2 SENDMAIL CONFIGURATION FILES
4 This document describes the sendmail configuration files. It
5 explains how to create a sendmail.cf file for use with sendmail.
6 It also describes how to set options for sendmail which are explained
7 in the Sendmail Installation and Operation guide (doc/op/op.me).
9 To get started, you may want to look at tcpproto.mc (for TCP-only
10 sites) and clientproto.mc (for clusters of clients using a single
11 mail host), or the generic-*.mc files as operating system-specific
16 INTRODUCTION AND EXAMPLE
17 A BRIEF INTRODUCTION TO M4
27 MASQUERADING AND RELAYING
28 USING LDAP FOR ALIASES, MAPS, AND CLASSES
30 ANTI-SPAM CONFIGURATION CONTROL
33 ADDING NEW MAILERS OR RULESETS
34 ADDING NEW MAIL FILTERS
35 QUEUE GROUP DEFINITIONS
36 NON-SMTP BASED CONFIGURATIONS
38 ACCEPTING MAIL FOR MULTIPLE NAMES
40 USING USERDB TO MAP FULL NAMES
41 MISCELLANEOUS SPECIAL FEATURES
43 TWEAKING CONFIGURATION OPTIONS
44 MESSAGE SUBMISSION PROGRAM
45 FORMAT OF FILES AND MAPS
47 ADMINISTRATIVE DETAILS
50 +--------------------------+
51 | INTRODUCTION AND EXAMPLE |
52 +--------------------------+
54 Configuration files are contained in the subdirectory "cf", with a
55 suffix ".mc". They must be run through "m4" to produce a ".cf" file.
56 You must pre-load "cf.m4":
58 m4 ${CFDIR}/m4/cf.m4 config.mc > config.cf
60 Alternatively, you can simply:
65 where ${CFDIR} is the root of the cf directory and config.mc is the
66 name of your configuration file. If you are running a version of M4
67 that understands the __file__ builtin (versions of GNU m4 >= 0.75 do
68 this, but the versions distributed with 4.4BSD and derivatives do not)
69 or the -I flag (ditto), then ${CFDIR} can be in an arbitrary directory.
70 For "traditional" versions, ${CFDIR} ***MUST*** be "..", or you MUST
71 use -D_CF_DIR_=/path/to/cf/dir/ -- note the trailing slash! For example:
73 m4 -D_CF_DIR_=${CFDIR}/ ${CFDIR}/m4/cf.m4 config.mc > config.cf
75 Let's examine a typical .mc file:
79 # Copyright (c) 1998-2002 Sendmail, Inc. and its suppliers.
80 # All rights reserved.
81 # Copyright (c) 1983 Eric P. Allman. All rights reserved.
82 # Copyright (c) 1988, 1993
83 # The Regents of the University of California. All rights reserved.
85 # By using this file, you agree to the terms and conditions set
86 # forth in the LICENSE file which can be found at the top level of
87 # the sendmail distribution.
91 # This is a Berkeley-specific configuration file for HP-UX 9.x.
92 # It applies only to the Computer Science Division at Berkeley,
93 # and should not be used elsewhere. It is provided on the sendmail
94 # distribution as a sample only. To create your own configuration
95 # file, create an appropriate domain file in ../domain, change the
96 # `DOMAIN' macro below to reference that file, and copy the result
97 # to a name of your own choosing.
101 The divert(-1) will delete the crud in the resulting output file.
102 The copyright notice can be replaced by whatever your lawyers require;
103 our lawyers require the one that is included in these files. A copyleft
104 is a copyright by another name. The divert(0) restores regular output.
106 VERSIONID(`<SCCS or RCS version id>')
108 VERSIONID is a macro that stuffs the version information into the
109 resulting file. You could use SCCS, RCS, CVS, something else, or
110 omit it completely. This is not the same as the version id included
111 in SMTP greeting messages -- this is defined in m4/version.m4.
115 You must specify an OSTYPE to properly configure things such as the
116 pathname of the help and status files, the flags needed for the local
117 mailer, and other important things. If you omit it, you will get an
118 error when you try to build the configuration. Look at the ostype
119 directory for the list of known operating system types.
121 DOMAIN(`CS.Berkeley.EDU')dnl
123 This example is specific to the Computer Science Division at Berkeley.
124 You can use "DOMAIN(`generic')" to get a sufficiently bland definition
125 that may well work for you, or you can create a customized domain
126 definition appropriate for your environment.
131 These describe the mailers used at the default CS site. The local
132 mailer is always included automatically. Beware: MAILER declarations
133 should always be at the end of the configuration file. The general
134 rules are that the order should be:
140 local macro definitions
146 There are a few exceptions to this rule. Local macro definitions which
147 influence a FEATURE() should be done before that feature. For example,
148 a define(`PROCMAIL_MAILER_PATH', ...) should be done before
149 FEATURE(`local_procmail').
151 *******************************************************************
152 *** BE SURE YOU CUSTOMIZE THESE FILES! They have some ***
153 *** Berkeley-specific assumptions built in, such as the name ***
154 *** of their UUCP-relay. You'll want to create your own ***
155 *** domain description, and use that in place of ***
156 *** domain/Berkeley.EDU.m4. ***
157 *******************************************************************
160 +----------------------------+
161 | A BRIEF INTRODUCTION TO M4 |
162 +----------------------------+
164 Sendmail uses the M4 macro processor to ``compile'' the configuration
165 files. The most important thing to know is that M4 is stream-based,
166 that is, it doesn't understand about lines. For this reason, in some
167 places you may see the word ``dnl'', which stands for ``delete
168 through newline''; essentially, it deletes all characters starting
169 at the ``dnl'' up to and including the next newline character. In
170 most cases sendmail uses this only to avoid lots of unnecessary
171 blank lines in the output.
173 Other important directives are define(A, B) which defines the macro
174 ``A'' to have value ``B''. Macros are expanded as they are read, so
175 one normally quotes both values to prevent expansion. For example,
177 define(`SMART_HOST', `smart.foo.com')
179 One word of warning: M4 macros are expanded even in lines that appear
180 to be comments. For example, if you have
182 # See FEATURE(`foo') above
184 it will not do what you expect, because the FEATURE(`foo') will be
185 expanded. This also applies to
187 # And then define the $X macro to be the return address
189 because ``define'' is an M4 keyword. If you want to use them, surround
190 them with directed quotes, `like this'.
192 Since m4 uses single quotes (opening "`" and closing "'") to quote
193 arguments, those quotes can't be used in arguments. For example,
194 it is not possible to define a rejection message containing a single
195 quote. Usually there are simple workarounds by changing those
196 messages; in the worst case it might be ok to change the value
197 directly in the generated .cf file, which however is not advised.
203 This package requires a post-V7 version of m4; if you are running the
204 4.2bsd, SysV.2, or 7th Edition version. SunOS's /usr/5bin/m4 or
205 BSD-Net/2's m4 both work. GNU m4 version 1.1 or later also works.
206 Unfortunately, the M4 on BSDI 1.0 doesn't work -- you'll have to use a
207 Net/2 or GNU version. GNU m4 is available from
208 ftp://ftp.gnu.org/pub/gnu/m4/m4-1.4.tar.gz (check for the latest version).
209 EXCEPTIONS: DEC's m4 on Digital UNIX 4.x is broken (3.x is fine). Use GNU
217 sendmail 8.9 has introduced a new configuration directory for sendmail
218 related files, /etc/mail. The new files available for sendmail 8.9 --
219 the class {R} /etc/mail/relay-domains and the access database
220 /etc/mail/access -- take advantage of this new directory. Beginning with
221 8.10, all files will use this directory by default (some options may be
222 set by OSTYPE() files). This new directory should help to restore
223 uniformity to sendmail's file locations.
225 Below is a table of some of the common changes:
227 Old filename New filename
228 ------------ ------------
229 /etc/bitdomain /etc/mail/bitdomain
230 /etc/domaintable /etc/mail/domaintable
231 /etc/genericstable /etc/mail/genericstable
232 /etc/uudomain /etc/mail/uudomain
233 /etc/virtusertable /etc/mail/virtusertable
234 /etc/userdb /etc/mail/userdb
236 /etc/aliases /etc/mail/aliases
237 /etc/sendmail/aliases /etc/mail/aliases
238 /etc/ucbmail/aliases /etc/mail/aliases
239 /usr/adm/sendmail/aliases /etc/mail/aliases
240 /usr/lib/aliases /etc/mail/aliases
241 /usr/lib/mail/aliases /etc/mail/aliases
242 /usr/ucblib/aliases /etc/mail/aliases
244 /etc/sendmail.cw /etc/mail/local-host-names
245 /etc/mail/sendmail.cw /etc/mail/local-host-names
246 /etc/sendmail/sendmail.cw /etc/mail/local-host-names
248 /etc/sendmail.ct /etc/mail/trusted-users
250 /etc/sendmail.oE /etc/mail/error-header
252 /etc/sendmail.hf /etc/mail/helpfile
253 /etc/mail/sendmail.hf /etc/mail/helpfile
254 /usr/ucblib/sendmail.hf /etc/mail/helpfile
255 /etc/ucbmail/sendmail.hf /etc/mail/helpfile
256 /usr/lib/sendmail.hf /etc/mail/helpfile
257 /usr/share/lib/sendmail.hf /etc/mail/helpfile
258 /usr/share/misc/sendmail.hf /etc/mail/helpfile
259 /share/misc/sendmail.hf /etc/mail/helpfile
261 /etc/service.switch /etc/mail/service.switch
263 /etc/sendmail.st /etc/mail/statistics
264 /etc/mail/sendmail.st /etc/mail/statistics
265 /etc/mailer/sendmail.st /etc/mail/statistics
266 /etc/sendmail/sendmail.st /etc/mail/statistics
267 /usr/lib/sendmail.st /etc/mail/statistics
268 /usr/ucblib/sendmail.st /etc/mail/statistics
270 Note that all of these paths actually use a new m4 macro MAIL_SETTINGS_DIR
271 to create the pathnames. The default value of this variable is
272 `/etc/mail/'. If you set this macro to a different value, you MUST include
275 Notice: all filenames used in a .mc (or .cf) file should be absolute
276 (starting at the root, i.e., with '/'). Relative filenames most
277 likely cause surprises during operations (unless otherwise noted).
284 You MUST define an operating system environment, or the configuration
285 file build will puke. There are several environments available; look
286 at the "ostype" directory for the current list. This macro changes
287 things like the location of the alias file and queue directory. Some
288 of these files are identical to one another.
290 It is IMPERATIVE that the OSTYPE occur before any MAILER definitions.
291 In general, the OSTYPE macro should go immediately after any version
292 information, and MAILER definitions should always go last.
294 Operating system definitions are usually easy to write. They may define
295 the following variables (everything defaults, so an ostype file may be
296 empty). Unfortunately, the list of configuration-supported systems is
297 not as broad as the list of source-supported systems, since many of
298 the source contributors do not include corresponding ostype files.
300 ALIAS_FILE [/etc/mail/aliases] The location of the text version
301 of the alias file(s). It can be a comma-separated
302 list of names (but be sure you quote values with
303 commas in them -- for example, use
304 define(`ALIAS_FILE', `a,b')
305 to get "a" and "b" both listed as alias files;
306 otherwise the define() primitive only sees "a").
307 HELP_FILE [/etc/mail/helpfile] The name of the file
308 containing information printed in response to
309 the SMTP HELP command.
310 QUEUE_DIR [/var/spool/mqueue] The directory containing
311 queue files. To use multiple queues, supply
312 a value ending with an asterisk. For
313 example, /var/spool/mqueue/qd* will use all of the
314 directories or symbolic links to directories
315 beginning with 'qd' in /var/spool/mqueue as queue
316 directories. The names 'qf', 'df', and 'xf' are
317 reserved as specific subdirectories for the
318 corresponding queue file types as explained in
319 doc/op/op.me. See also QUEUE GROUP DEFINITIONS.
320 MSP_QUEUE_DIR [/var/spool/clientmqueue] The directory containing
321 queue files for the MSP (Mail Submission Program,
322 see sendmail/SECURITY).
323 STATUS_FILE [/etc/mail/statistics] The file containing status
325 LOCAL_MAILER_PATH [/bin/mail] The program used to deliver local mail.
326 LOCAL_MAILER_FLAGS [Prmn9] The flags used by the local mailer. The
327 flags lsDFMAw5:/|@q are always included.
328 LOCAL_MAILER_ARGS [mail -d $u] The arguments passed to deliver local
330 LOCAL_MAILER_MAX [undefined] If defined, the maximum size of local
331 mail that you are willing to accept.
332 LOCAL_MAILER_MAXMSGS [undefined] If defined, the maximum number of
333 messages to deliver in a single connection. Only
334 useful for LMTP local mailers.
335 LOCAL_MAILER_CHARSET [undefined] If defined, messages containing 8-bit data
336 that ARRIVE from an address that resolves to the
337 local mailer and which are converted to MIME will be
338 labeled with this character set.
339 LOCAL_MAILER_EOL [undefined] If defined, the string to use as the
340 end of line for the local mailer.
341 LOCAL_MAILER_DSN_DIAGNOSTIC_CODE
342 [X-Unix] The DSN Diagnostic-Code value for the
343 local mailer. This should be changed with care.
344 LOCAL_SHELL_PATH [/bin/sh] The shell used to deliver piped email.
345 LOCAL_SHELL_FLAGS [eu9] The flags used by the shell mailer. The
346 flags lsDFM are always included.
347 LOCAL_SHELL_ARGS [sh -c $u] The arguments passed to deliver "prog"
349 LOCAL_SHELL_DIR [$z:/] The directory search path in which the
351 LOCAL_MAILER_QGRP [undefined] The queue group for the local mailer.
352 USENET_MAILER_PATH [/usr/lib/news/inews] The name of the program
354 USENET_MAILER_FLAGS [rsDFMmn] The mailer flags for the usenet mailer.
355 USENET_MAILER_ARGS [-m -h -n] The command line arguments for the
356 usenet mailer. NOTE: Some versions of inews
357 (such as those shipped with newer versions of INN)
358 use different flags. Double check the defaults
359 against the inews man page.
360 USENET_MAILER_MAX [undefined] The maximum size of messages that will
361 be accepted by the usenet mailer.
362 USENET_MAILER_QGRP [undefined] The queue group for the usenet mailer.
363 SMTP_MAILER_FLAGS [undefined] Flags added to SMTP mailer. Default
364 flags are `mDFMuX' for all SMTP-based mailers; the
365 "esmtp" mailer adds `a'; "smtp8" adds `8'; and
367 RELAY_MAILER_FLAGS [undefined] Flags added to the relay mailer. Default
368 flags are `mDFMuX' for all SMTP-based mailers; the
369 relay mailer adds `a8'. If this is not defined,
370 then SMTP_MAILER_FLAGS is used.
371 SMTP_MAILER_MAX [undefined] The maximum size of messages that will
372 be transported using the smtp, smtp8, esmtp, or dsmtp
374 SMTP_MAILER_MAXMSGS [undefined] If defined, the maximum number of
375 messages to deliver in a single connection for the
376 smtp, smtp8, esmtp, or dsmtp mailers.
377 SMTP_MAILER_MAXRCPTS [undefined] If defined, the maximum number of
378 recipients to deliver in a single connection for the
379 smtp, smtp8, esmtp, or dsmtp mailers.
380 SMTP_MAILER_ARGS [TCP $h] The arguments passed to the smtp mailer.
381 About the only reason you would want to change this
382 would be to change the default port.
383 ESMTP_MAILER_ARGS [TCP $h] The arguments passed to the esmtp mailer.
384 SMTP8_MAILER_ARGS [TCP $h] The arguments passed to the smtp8 mailer.
385 DSMTP_MAILER_ARGS [TCP $h] The arguments passed to the dsmtp mailer.
386 RELAY_MAILER_ARGS [TCP $h] The arguments passed to the relay mailer.
387 SMTP_MAILER_QGRP [undefined] The queue group for the smtp mailer.
388 ESMTP_MAILER_QGRP [undefined] The queue group for the esmtp mailer.
389 SMTP8_MAILER_QGRP [undefined] The queue group for the smtp8 mailer.
390 DSMTP_MAILER_QGRP [undefined] The queue group for the dsmtp mailer.
391 RELAY_MAILER_QGRP [undefined] The queue group for the relay mailer.
392 RELAY_MAILER_MAXMSGS [undefined] If defined, the maximum number of
393 messages to deliver in a single connection for the
395 SMTP_MAILER_CHARSET [undefined] If defined, messages containing 8-bit data
396 that ARRIVE from an address that resolves to one of
397 the SMTP mailers and which are converted to MIME will
398 be labeled with this character set.
399 UUCP_MAILER_PATH [/usr/bin/uux] The program used to send UUCP mail.
400 UUCP_MAILER_FLAGS [undefined] Flags added to UUCP mailer. Default
401 flags are `DFMhuU' (and `m' for uucp-new mailer,
402 minus `U' for uucp-dom mailer).
403 UUCP_MAILER_ARGS [uux - -r -z -a$g -gC $h!rmail ($u)] The arguments
404 passed to the UUCP mailer.
405 UUCP_MAILER_MAX [100000] The maximum size message accepted for
406 transmission by the UUCP mailers.
407 UUCP_MAILER_CHARSET [undefined] If defined, messages containing 8-bit data
408 that ARRIVE from an address that resolves to one of
409 the UUCP mailers and which are converted to MIME will
410 be labeled with this character set.
411 UUCP_MAILER_QGRP [undefined] The queue group for the UUCP mailers.
412 FAX_MAILER_PATH [/usr/local/lib/fax/mailfax] The program used to
414 FAX_MAILER_ARGS [mailfax $u $h $f] The arguments passed to the FAX
416 FAX_MAILER_MAX [100000] The maximum size message accepted for
418 POP_MAILER_PATH [/usr/lib/mh/spop] The pathname of the POP mailer.
419 POP_MAILER_FLAGS [Penu] Flags added to POP mailer. Flags lsDFMq
421 POP_MAILER_ARGS [pop $u] The arguments passed to the POP mailer.
422 POP_MAILER_QGRP [undefined] The queue group for the pop mailer.
423 PROCMAIL_MAILER_PATH [/usr/local/bin/procmail] The path to the procmail
424 program. This is also used by
425 FEATURE(`local_procmail').
426 PROCMAIL_MAILER_FLAGS [SPhnu9] Flags added to Procmail mailer. Flags
427 DFM are always set. This is NOT used by
428 FEATURE(`local_procmail'); tweak LOCAL_MAILER_FLAGS
430 PROCMAIL_MAILER_ARGS [procmail -Y -m $h $f $u] The arguments passed to
431 the Procmail mailer. This is NOT used by
432 FEATURE(`local_procmail'); tweak LOCAL_MAILER_ARGS
434 PROCMAIL_MAILER_MAX [undefined] If set, the maximum size message that
435 will be accepted by the procmail mailer.
436 PROCMAIL_MAILER_QGRP [undefined] The queue group for the procmail mailer.
437 MAIL11_MAILER_PATH [/usr/etc/mail11] The path to the mail11 mailer.
438 MAIL11_MAILER_FLAGS [nsFx] Flags for the mail11 mailer.
439 MAIL11_MAILER_ARGS [mail11 $g $x $h $u] Arguments passed to the mail11
441 MAIL11_MAILER_QGRP [undefined] The queue group for the mail11 mailer.
442 PH_MAILER_PATH [/usr/local/etc/phquery] The path to the phquery
444 PH_MAILER_FLAGS [ehmu] Flags for the phquery mailer. Flags nrDFM
446 PH_MAILER_ARGS [phquery -- $u] -- arguments to the phquery mailer.
447 PH_MAILER_QGRP [undefined] The queue group for the ph mailer.
448 CYRUS_MAILER_FLAGS [Ah5@/:|] The flags used by the cyrus mailer. The
449 flags lsDFMnPq are always included.
450 CYRUS_MAILER_PATH [/usr/cyrus/bin/deliver] The program used to deliver
452 CYRUS_MAILER_ARGS [deliver -e -m $h -- $u] The arguments passed
453 to deliver cyrus mail.
454 CYRUS_MAILER_MAX [undefined] If set, the maximum size message that
455 will be accepted by the cyrus mailer.
456 CYRUS_MAILER_USER [cyrus:mail] The user and group to become when
457 running the cyrus mailer.
458 CYRUS_MAILER_QGRP [undefined] The queue group for the cyrus mailer.
459 CYRUS_BB_MAILER_FLAGS [u] The flags used by the cyrusbb mailer.
460 The flags lsDFMnP are always included.
461 CYRUS_BB_MAILER_ARGS [deliver -e -m $u] The arguments passed
462 to deliver cyrusbb mail.
463 CYRUSV2_MAILER_FLAGS [A@/:|m] The flags used by the cyrusv2 mailer. The
464 flags lsDFMnqXz are always included.
465 CYRUSV2_MAILER_MAXMSGS [undefined] If defined, the maximum number of
466 messages to deliver in a single connection for the
468 CYRUSV2_MAILER_MAXRCPTS [undefined] If defined, the maximum number of
469 recipients to deliver in a single connection for the
471 CYRUSV2_MAILER_ARGS [FILE /var/imap/socket/lmtp] The arguments passed
472 to the cyrusv2 mailer. This can be used to
473 change the name of the Unix domain socket, or
474 to switch to delivery via TCP (e.g., `TCP $h lmtp')
475 CYRUSV2_MAILER_QGRP [undefined] The queue group for the cyrusv2 mailer.
476 CYRUSV2_MAILER_CHARSET [undefined] If defined, messages containing 8-bit data
477 that ARRIVE from an address that resolves to one the
478 Cyrus mailer and which are converted to MIME will
479 be labeled with this character set.
480 confEBINDIR [/usr/libexec] The directory for executables.
481 Currently used for FEATURE(`local_lmtp') and
483 QPAGE_MAILER_FLAGS [mDFMs] The flags used by the qpage mailer.
484 QPAGE_MAILER_PATH [/usr/local/bin/qpage] The program used to deliver
486 QPAGE_MAILER_ARGS [qpage -l0 -m -P$u] The arguments passed
487 to deliver qpage mail.
488 QPAGE_MAILER_MAX [4096] If set, the maximum size message that
489 will be accepted by the qpage mailer.
490 QPAGE_MAILER_QGRP [undefined] The queue group for the qpage mailer.
491 LOCAL_PROG_QGRP [undefined] The queue group for the prog mailer.
493 Note: to tweak Name_MAILER_FLAGS use the macro MODIFY_MAILER_FLAGS:
494 MODIFY_MAILER_FLAGS(`Name', `change') where Name is the first part of
495 the macro Name_MAILER_FLAGS and change can be: flags that should
496 be used directly (thus overriding the default value), or if it
497 starts with `+' (`-') then those flags are added to (removed from)
498 the default value. Example:
500 MODIFY_MAILER_FLAGS(`LOCAL', `+e')
502 will add the flag `e' to LOCAL_MAILER_FLAGS. Notice: there are
503 several smtp mailers all of which are manipulated individually.
504 See the section MAILERS for the available mailer names.
505 WARNING: The FEATUREs local_lmtp and local_procmail set LOCAL_MAILER_FLAGS
506 unconditionally, i.e., without respecting any definitions in an
514 You will probably want to collect domain-dependent defines into one
515 file, referenced by the DOMAIN macro. For example, the Berkeley
516 domain file includes definitions for several internal distinguished
519 UUCP_RELAY The host that will accept UUCP-addressed email.
520 If not defined, all UUCP sites must be directly
522 BITNET_RELAY The host that will accept BITNET-addressed email.
523 If not defined, the .BITNET pseudo-domain won't work.
524 DECNET_RELAY The host that will accept DECNET-addressed email.
525 If not defined, the .DECNET pseudo-domain and addresses
526 of the form node::user will not work.
527 FAX_RELAY The host that will accept mail to the .FAX pseudo-domain.
528 The "fax" mailer overrides this value.
529 LOCAL_RELAY The site that will handle unqualified names -- that
530 is, names without an @domain extension.
531 Normally MAIL_HUB is preferred for this function.
532 LOCAL_RELAY is mostly useful in conjunction with
533 FEATURE(`stickyhost') -- see the discussion of
534 stickyhost below. If not set, they are assumed to
535 belong on this machine. This allows you to have a
536 central site to store a company- or department-wide
537 alias database. This only works at small sites,
538 and only with some user agents.
539 LUSER_RELAY The site that will handle lusers -- that is, apparently
540 local names that aren't local accounts or aliases. To
541 specify a local user instead of a site, set this to
544 Any of these can be either ``mailer:hostname'' (in which case the
545 mailer is the internal mailer name, such as ``uucp-new'' and the hostname
546 is the name of the host as appropriate for that mailer) or just a
547 ``hostname'', in which case a default mailer type (usually ``relay'',
548 a variant on SMTP) is used. WARNING: if you have a wildcard MX
549 record matching your domain, you probably want to define these to
550 have a trailing dot so that you won't get the mail diverted back
553 The domain file can also be used to define a domain name, if needed
554 (using "DD<domain>") and set certain site-wide features. If all hosts
555 at your site masquerade behind one email name, you could also use
558 You do not have to define a domain -- in particular, if you are a
559 single machine sitting off somewhere, it is probably more work than
560 it's worth. This is just a mechanism for combining "domain dependent
561 knowledge" into one place.
568 There are fewer mailers supported in this version than the previous
569 version, owing mostly to a simpler world. As a general rule, put the
570 MAILER definitions last in your .mc file.
572 local The local and prog mailers. You will almost always
573 need these; the only exception is if you relay ALL
574 your mail to another site. This mailer is included
577 smtp The Simple Mail Transport Protocol mailer. This does
578 not hide hosts behind a gateway or another other
579 such hack; it assumes a world where everyone is
580 running the name server. This file actually defines
581 five mailers: "smtp" for regular (old-style) SMTP to
582 other servers, "esmtp" for extended SMTP to other
583 servers, "smtp8" to do SMTP to other servers without
584 converting 8-bit data to MIME (essentially, this is
585 your statement that you know the other end is 8-bit
586 clean even if it doesn't say so), "dsmtp" to do on
587 demand delivery, and "relay" for transmission to the
588 RELAY_HOST, LUSER_RELAY, or MAIL_HUB.
590 uucp The UNIX-to-UNIX Copy Program mailer. Actually, this
591 defines two mailers, "uucp-old" (a.k.a. "uucp") and
592 "uucp-new" (a.k.a. "suucp"). The latter is for when you
593 know that the UUCP mailer at the other end can handle
594 multiple recipients in one transfer. If the smtp mailer
595 is included in your configuration, two other mailers
596 ("uucp-dom" and "uucp-uudom") are also defined [warning: you
597 MUST specify MAILER(`smtp') before MAILER(`uucp')]. When you
598 include the uucp mailer, sendmail looks for all names in
599 class {U} and sends them to the uucp-old mailer; all
600 names in class {Y} are sent to uucp-new; and all
601 names in class {Z} are sent to uucp-uudom. Note that
602 this is a function of what version of rmail runs on
603 the receiving end, and hence may be out of your control.
604 See the section below describing UUCP mailers in more
607 usenet Usenet (network news) delivery. If this is specified,
608 an extra rule is added to ruleset 0 that forwards all
609 local email for users named ``group.usenet'' to the
610 ``inews'' program. Note that this works for all groups,
611 and may be considered a security problem.
613 fax Facsimile transmission. This is experimental and based
614 on Sam Leffler's HylaFAX software. For more information,
615 see http://www.hylafax.org/.
617 pop Post Office Protocol.
619 procmail An interface to procmail (does not come with sendmail).
620 This is designed to be used in mailertables. For example,
621 a common question is "how do I forward all mail for a given
622 domain to a single person?". If you have this mailer
623 defined, you could set up a mailertable reading:
625 host.com procmail:/etc/procmailrcs/host.com
627 with the file /etc/procmailrcs/host.com reading:
629 :0 # forward mail for host.com
630 ! -oi -f $1 person@other.host
632 This would arrange for (anything)@host.com to be sent
633 to person@other.host. In a procmail script, $1 is the
634 name of the sender and $2 is the name of the recipient.
635 If you use this with FEATURE(`local_procmail'), the FEATURE
636 should be listed first.
638 Of course there are other ways to solve this particular
639 problem, e.g., a catch-all entry in a virtusertable.
641 mail11 The DECnet mail11 mailer, useful only if you have the mail11
642 program from gatekeeper.dec.com:/pub/DEC/gwtools (and
643 DECnet, of course). This is for Phase IV DECnet support;
644 if you have Phase V at your site you may have additional
647 phquery The phquery program. This is somewhat counterintuitively
648 referenced as the "ph" mailer internally. It can be used
649 to do CCSO name server lookups. The phquery program, which
650 this mailer uses, is distributed with the ph client.
652 cyrus The cyrus and cyrusbb mailers. The cyrus mailer delivers to
653 a local cyrus user. this mailer can make use of the
654 "user+detail@local.host" syntax (see
655 FEATURE(`preserve_local_plus_detail')); it will deliver the
656 mail to the user's "detail" mailbox if the mailbox's ACL
657 permits. The cyrusbb mailer delivers to a system-wide
658 cyrus mailbox if the mailbox's ACL permits. The cyrus
659 mailer must be defined after the local mailer.
661 cyrusv2 The mailer for Cyrus v2.x. The cyrusv2 mailer delivers to
662 local cyrus users via LMTP. This mailer can make use of the
663 "user+detail@local.host" syntax (see
664 FEATURE(`preserve_local_plus_detail')); it will deliver the
665 mail to the user's "detail" mailbox if the mailbox's ACL
666 permits. The cyrusv2 mailer must be defined after the
669 qpage A mailer for QuickPage, a pager interface. See
670 http://www.qpage.org/ for further information.
672 The local mailer accepts addresses of the form "user+detail", where
673 the "+detail" is not used for mailbox matching but is available
674 to certain local mail programs (in particular, see
675 FEATURE(`local_procmail')). For example, "eric", "eric+sendmail", and
676 "eric+sww" all indicate the same user, but additional arguments <null>,
677 "sendmail", and "sww" may be provided for use in sorting mail.
684 Special features can be requested using the "FEATURE" macro. For
685 example, the .mc line:
687 FEATURE(`use_cw_file')
689 tells sendmail that you want to have it read an /etc/mail/local-host-names
690 file to get values for class {w}. A FEATURE may contain up to 9
691 optional parameters -- for example:
693 FEATURE(`mailertable', `dbm /usr/lib/mailertable')
695 The default database map type for the table features can be set with
697 define(`DATABASE_MAP_TYPE', `dbm')
699 which would set it to use ndbm databases. The default is the Berkeley DB
700 hash database format. Note that you must still declare a database map type
701 if you specify an argument to a FEATURE. DATABASE_MAP_TYPE is only used
702 if no argument is given for the FEATURE. It must be specified before any
703 feature that uses a map.
705 Also, features which can take a map definition as an argument can also take
706 the special keyword `LDAP'. If that keyword is used, the map will use the
707 LDAP definition described in the ``USING LDAP FOR ALIASES, MAPS, AND
708 CLASSES'' section below.
710 Available features are:
712 use_cw_file Read the file /etc/mail/local-host-names file to get
713 alternate names for this host. This might be used if you
714 were on a host that MXed for a dynamic set of other hosts.
715 If the set is static, just including the line "Cw<name1>
716 <name2> ..." (where the names are fully qualified domain
717 names) is probably superior. The actual filename can be
718 overridden by redefining confCW_FILE.
720 use_ct_file Read the file /etc/mail/trusted-users file to get the
721 names of users that will be ``trusted'', that is, able to
722 set their envelope from address using -f without generating
723 a warning message. The actual filename can be overridden
724 by redefining confCT_FILE.
726 redirect Reject all mail addressed to "address.REDIRECT" with
727 a ``551 User has moved; please try <address>'' message.
728 If this is set, you can alias people who have left
729 to their new address with ".REDIRECT" appended.
731 nouucp Don't route UUCP addresses. This feature takes one
733 `reject': reject addresses which have "!" in the local
734 part unless it originates from a system
735 that is allowed to relay.
736 `nospecial': don't do anything special with "!".
737 Warnings: 1. See the notice in the anti-spam section.
738 2. don't remove "!" from OperatorChars if `reject' is
741 nocanonify Don't pass addresses to $[ ... $] for canonification
742 by default, i.e., host/domain names are considered canonical,
743 except for unqualified names, which must not be used in this
744 mode (violation of the standard). It can be changed by
745 setting the DaemonPortOptions modifiers (M=). That is,
746 FEATURE(`nocanonify') will be overridden by setting the
747 'c' flag. Conversely, if FEATURE(`nocanonify') is not used,
748 it can be emulated by setting the 'C' flag
749 (DaemonPortOptions=Modifiers=C). This would generally only
750 be used by sites that only act as mail gateways or which have
751 user agents that do full canonification themselves. You may
753 "define(`confBIND_OPTS', `-DNSRCH -DEFNAMES')" to turn off
754 the usual resolver options that do a similar thing.
756 An exception list for FEATURE(`nocanonify') can be
757 specified with CANONIFY_DOMAIN or CANONIFY_DOMAIN_FILE,
758 i.e., a list of domains which are nevertheless passed to
759 $[ ... $] for canonification. This is useful to turn on
760 canonification for local domains, e.g., use
761 CANONIFY_DOMAIN(`my.domain my') to canonify addresses
762 which end in "my.domain" or "my".
763 Another way to require canonification in the local
764 domain is CANONIFY_DOMAIN(`$=m').
766 A trailing dot is added to addresses with more than
767 one component in it such that other features which
768 expect a trailing dot (e.g., virtusertable) will
771 If `canonify_hosts' is specified as parameter, i.e.,
772 FEATURE(`nocanonify', `canonify_hosts'), then
773 addresses which have only a hostname, e.g.,
774 <user@host>, will be canonified (and hopefully fully
777 stickyhost This feature is sometimes used with LOCAL_RELAY,
778 although it can be used for a different effect with
781 When used without MAIL_HUB, email sent to
782 "user@local.host" are marked as "sticky" -- that
783 is, the local addresses aren't matched against UDB,
784 don't go through ruleset 5, and are not forwarded to
785 the LOCAL_RELAY (if defined).
787 With MAIL_HUB, mail addressed to "user@local.host"
788 is forwarded to the mail hub, with the envelope
789 address still remaining "user@local.host".
790 Without stickyhost, the envelope would be changed
791 to "user@mail_hub", in order to protect against
794 mailertable Include a "mailer table" which can be used to override
795 routing for particular domains (which are not in class {w},
796 i.e. local host names). The argument of the FEATURE may be
797 the key definition. If none is specified, the definition
800 hash /etc/mail/mailertable
802 Keys in this database are fully qualified domain names
803 or partial domains preceded by a dot -- for example,
804 "vangogh.CS.Berkeley.EDU" or ".CS.Berkeley.EDU". As a
805 special case of the latter, "." matches any domain not
806 covered by other keys. Values must be of the form:
808 where "mailer" is the internal mailer name, and "domain"
809 is where to send the message. These maps are not
810 reflected into the message header. As a special case,
813 will forward to the indicated user using the local mailer,
815 will forward to the original user in the e-mail address
816 using the local mailer, and
818 error:D.S.N:code message
819 will give an error message with the indicated SMTP reply
820 code and message, where D.S.N is an RFC 1893 compliant
823 domaintable Include a "domain table" which can be used to provide
824 domain name mapping. Use of this should really be
825 limited to your own domains. It may be useful if you
826 change names (e.g., your company changes names from
827 oldname.com to newname.com). The argument of the
828 FEATURE may be the key definition. If none is specified,
829 the definition used is:
831 hash /etc/mail/domaintable
833 The key in this table is the domain name; the value is
834 the new (fully qualified) domain. Anything in the
835 domaintable is reflected into headers; that is, this
836 is done in ruleset 3.
838 bitdomain Look up bitnet hosts in a table to try to turn them into
839 internet addresses. The table can be built using the
840 bitdomain program contributed by John Gardiner Myers.
841 The argument of the FEATURE may be the key definition; if
842 none is specified, the definition used is:
844 hash /etc/mail/bitdomain
846 Keys are the bitnet hostname; values are the corresponding
849 uucpdomain Similar feature for UUCP hosts. The default map definition
852 hash /etc/mail/uudomain
854 At the moment there is no automagic tool to build this
858 Include the local host domain even on locally delivered
859 mail. Normally it is not added on unqualified names.
860 However, if you use a shared message store but do not use
861 the same user name space everywhere, you may need the host
862 name on local names. An optional argument specifies
863 another domain to be added than the local.
865 allmasquerade If masquerading is enabled (using MASQUERADE_AS), this
866 feature will cause recipient addresses to also masquerade
867 as being from the masquerade host. Normally they get
868 the local hostname. Although this may be right for
869 ordinary users, it can break local aliases. For example,
870 if you send to "localalias", the originating sendmail will
871 find that alias and send to all members, but send the
872 message with "To: localalias@masqueradehost". Since that
873 alias likely does not exist, replies will fail. Use this
874 feature ONLY if you can guarantee that the ENTIRE
875 namespace on your masquerade host supersets all the
879 Normally, any hosts listed in class {w} are masqueraded. If
880 this feature is given, only the hosts listed in class {M} (see
881 below: MASQUERADE_DOMAIN) are masqueraded. This is useful
882 if you have several domains with disjoint namespaces hosted
885 masquerade_entire_domain
886 If masquerading is enabled (using MASQUERADE_AS) and
887 MASQUERADE_DOMAIN (see below) is set, this feature will
888 cause addresses to be rewritten such that the masquerading
889 domains are actually entire domains to be hidden. All
890 hosts within the masquerading domains will be rewritten
891 to the masquerade name (used in MASQUERADE_AS). For example,
894 MASQUERADE_AS(`masq.com')
895 MASQUERADE_DOMAIN(`foo.org')
896 MASQUERADE_DOMAIN(`bar.com')
898 then *foo.org and *bar.com are converted to masq.com. Without
899 this feature, only foo.org and bar.com are masqueraded.
901 NOTE: only domains within your jurisdiction and
902 current hierarchy should be masqueraded using this.
905 This feature prevents the local mailer from masquerading even
906 if MASQUERADE_AS is used. MASQUERADE_AS will only have effect
907 on addresses of mail going outside the local domain.
910 If masquerading is enabled (using MASQUERADE_AS) or the
911 genericstable is in use, this feature will cause envelope
912 addresses to also masquerade as being from the masquerade
913 host. Normally only the header addresses are masqueraded.
915 genericstable This feature will cause unqualified addresses (i.e., without
916 a domain) and addresses with a domain listed in class {G}
917 to be looked up in a map and turned into another ("generic")
918 form, which can change both the domain name and the user name.
919 Notice: if you use an MSP (as it is default starting with
920 8.12), the MTA will only receive qualified addresses from the
921 MSP (as required by the RFCs). Hence you need to add your
922 domain to class {G}. This feature is similar to the userdb
923 functionality. The same types of addresses as for
924 masquerading are looked up, i.e., only header sender
925 addresses unless the allmasquerade and/or masquerade_envelope
926 features are given. Qualified addresses must have the domain
927 part in class {G}; entries can be added to this class by the
928 macros GENERICS_DOMAIN or GENERICS_DOMAIN_FILE (analogously
929 to MASQUERADE_DOMAIN and MASQUERADE_DOMAIN_FILE, see below).
931 The argument of FEATURE(`genericstable') may be the map
932 definition; the default map definition is:
934 hash /etc/mail/genericstable
936 The key for this table is either the full address, the domain
937 (with a leading @; the localpart is passed as first argument)
938 or the unqualified username (tried in the order mentioned);
939 the value is the new user address. If the new user address
940 does not include a domain, it will be qualified in the standard
941 manner, i.e., using $j or the masquerade name. Note that the
942 address being looked up must be fully qualified. For local
943 mail, it is necessary to use FEATURE(`always_add_domain')
944 for the addresses to be qualified.
945 The "+detail" of an address is passed as %1, so entries like
947 old+*@foo.org new+%1@example.com
948 gen+*@foo.org %1@example.com
950 and other forms are possible.
952 generics_entire_domain
953 If the genericstable is enabled and GENERICS_DOMAIN or
954 GENERICS_DOMAIN_FILE is used, this feature will cause
955 addresses to be searched in the map if their domain
956 parts are subdomains of elements in class {G}.
958 virtusertable A domain-specific form of aliasing, allowing multiple
959 virtual domains to be hosted on one machine. For example,
960 if the virtuser table contained:
962 info@foo.com foo-info
963 info@bar.com bar-info
964 joe@bar.com error:nouser 550 No such user here
965 jax@bar.com error:5.7.0:550 Address invalid
966 @baz.org jane@example.net
968 then mail addressed to info@foo.com will be sent to the
969 address foo-info, mail addressed to info@bar.com will be
970 delivered to bar-info, and mail addressed to anyone at baz.org
971 will be sent to jane@example.net, mail to joe@bar.com will
972 be rejected with the specified error message, and mail to
973 jax@bar.com will also have a RFC 1893 compliant error code
976 The username from the original address is passed
979 @foo.org %1@example.com
981 meaning someone@foo.org will be sent to someone@example.com.
982 Additionally, if the local part consists of "user+detail"
983 then "detail" is passed as %2 and "+detail" is passed as %3
984 when a match against user+* is attempted, so entries like
986 old+*@foo.org new+%2@example.com
987 gen+*@foo.org %2@example.com
988 +*@foo.org %1%3@example.com
989 X++@foo.org Z%3@example.com
992 and other forms are possible. Note: to preserve "+detail"
993 for a default case (@domain) %1%3 must be used as RHS.
994 There are two wildcards after "+": "+" matches only a non-empty
995 detail, "*" matches also empty details, e.g., user+@foo.org
996 matches +*@foo.org but not ++@foo.org. This can be used
997 to ensure that the parameters %2 and %3 are not empty.
999 All the host names on the left hand side (foo.com, bar.com,
1000 and baz.org) must be in class {w} or class {VirtHost}. The
1001 latter can be defined by the macros VIRTUSER_DOMAIN or
1002 VIRTUSER_DOMAIN_FILE (analogously to MASQUERADE_DOMAIN and
1003 MASQUERADE_DOMAIN_FILE, see below). If VIRTUSER_DOMAIN or
1004 VIRTUSER_DOMAIN_FILE is used, then the entries of class
1005 {VirtHost} are added to class {R}, i.e., relaying is allowed
1006 to (and from) those domains. The default map definition is:
1008 hash /etc/mail/virtusertable
1010 A new definition can be specified as the second argument of
1011 the FEATURE macro, such as
1013 FEATURE(`virtusertable', `dbm /etc/mail/virtusers')
1015 virtuser_entire_domain
1016 If the virtusertable is enabled and VIRTUSER_DOMAIN or
1017 VIRTUSER_DOMAIN_FILE is used, this feature will cause
1018 addresses to be searched in the map if their domain
1019 parts are subdomains of elements in class {VirtHost}.
1021 ldap_routing Implement LDAP-based e-mail recipient routing according to
1022 the Internet Draft draft-lachman-laser-ldap-mail-routing-01.
1023 This provides a method to re-route addresses with a
1024 domain portion in class {LDAPRoute} to either a
1025 different mail host or a different address. Hosts can
1026 be added to this class using LDAPROUTE_DOMAIN and
1027 LDAPROUTE_DOMAIN_FILE (analogously to MASQUERADE_DOMAIN and
1028 MASQUERADE_DOMAIN_FILE, see below).
1030 See the LDAP ROUTING section below for more information.
1032 nodns If you aren't running DNS at your site (for example,
1033 you are UUCP-only connected). It's hard to consider
1034 this a "feature", but hey, it had to go somewhere.
1035 Actually, as of 8.7 this is a no-op -- remove "dns" from
1036 the hosts service switch entry instead.
1038 nullclient This is a special case -- it creates a configuration file
1039 containing nothing but support for forwarding all mail to a
1040 central hub via a local SMTP-based network. The argument
1041 is the name of that hub.
1043 The only other feature that should be used in conjunction
1044 with this one is FEATURE(`nocanonify'). No mailers
1045 should be defined. No aliasing or forwarding is done.
1047 local_lmtp Use an LMTP capable local mailer. The argument to this
1048 feature is the pathname of an LMTP capable mailer. By
1049 default, mail.local is used. This is expected to be the
1050 mail.local which came with the 8.9 distribution which is
1051 LMTP capable. The path to mail.local is set by the
1052 confEBINDIR m4 variable -- making the default
1053 LOCAL_MAILER_PATH /usr/libexec/mail.local.
1054 WARNING: This feature sets LOCAL_MAILER_FLAGS unconditionally,
1055 i.e., without respecting any definitions in an OSTYPE setting.
1057 local_procmail Use procmail or another delivery agent as the local mailer.
1058 The argument to this feature is the pathname of the
1059 delivery agent, which defaults to PROCMAIL_MAILER_PATH.
1060 Note that this does NOT use PROCMAIL_MAILER_FLAGS or
1061 PROCMAIL_MAILER_ARGS for the local mailer; tweak
1062 LOCAL_MAILER_FLAGS and LOCAL_MAILER_ARGS instead, or
1063 specify the appropriate parameters. When procmail is used,
1064 the local mailer can make use of the
1065 "user+indicator@local.host" syntax; normally the +indicator
1066 is just tossed, but by default it is passed as the -a
1067 argument to procmail.
1069 This feature can take up to three arguments:
1071 1. Path to the mailer program
1072 [default: /usr/local/bin/procmail]
1073 2. Argument vector including name of the program
1074 [default: procmail -Y -a $h -d $u]
1075 3. Flags for the mailer [default: SPfhn9]
1077 Empty arguments cause the defaults to be taken.
1078 Note that if you are on a system with a broken
1079 setreuid() call, you may need to add -f $f to the procmail
1080 argument vector to pass the proper sender to procmail.
1082 For example, this allows it to use the maildrop
1083 (http://www.flounder.net/~mrsam/maildrop/) mailer instead
1086 FEATURE(`local_procmail', `/usr/local/bin/maildrop',
1091 FEATURE(`local_procmail', `/usr/local/bin/scanmails')
1093 WARNING: This feature sets LOCAL_MAILER_FLAGS unconditionally,
1094 i.e., without respecting any definitions in an OSTYPE setting.
1096 bestmx_is_local Accept mail as though locally addressed for any host that
1097 lists us as the best possible MX record. This generates
1098 additional DNS traffic, but should be OK for low to
1099 medium traffic hosts. The argument may be a set of
1100 domains, which will limit the feature to only apply to
1101 these domains -- this will reduce unnecessary DNS
1102 traffic. THIS FEATURE IS FUNDAMENTALLY INCOMPATIBLE WITH
1103 WILDCARD MX RECORDS!!! If you have a wildcard MX record
1104 that matches your domain, you cannot use this feature.
1106 smrsh Use the SendMail Restricted SHell (smrsh) provided
1107 with the distribution instead of /bin/sh for mailing
1108 to programs. This improves the ability of the local
1109 system administrator to control what gets run via
1110 e-mail. If an argument is provided it is used as the
1111 pathname to smrsh; otherwise, the path defined by
1112 confEBINDIR is used for the smrsh binary -- by default,
1113 /usr/libexec/smrsh is assumed.
1116 By default, the sendmail configuration files do not permit
1117 mail relaying (that is, accepting mail from outside your
1118 local host (class {w}) and sending it to another host than
1119 your local host). This option sets your site to allow
1120 mail relaying from any site to any site. In almost all
1121 cases, it is better to control relaying more carefully
1122 with the access map, class {R}, or authentication. Domains
1123 can be added to class {R} by the macros RELAY_DOMAIN or
1124 RELAY_DOMAIN_FILE (analogously to MASQUERADE_DOMAIN and
1125 MASQUERADE_DOMAIN_FILE, see below).
1128 This option allows any host in your domain as defined by
1129 class {m} to use your server for relaying. Notice: make
1130 sure that your domain is not just a top level domain,
1131 e.g., com. This can happen if you give your host a name
1132 like example.com instead of host.example.com.
1135 By default, names that are listed as RELAY in the access
1136 db and class {R} are treated as domain names, not host names.
1137 For example, if you specify ``foo.com'', then mail to or
1138 from foo.com, abc.foo.com, or a.very.deep.domain.foo.com
1139 will all be accepted for relaying. This feature changes
1140 the behaviour to lookup individual host names only.
1143 Turns on the ability to allow relaying based on the MX
1144 records of the host portion of an incoming recipient; that
1145 is, if an MX record for host foo.com points to your site,
1146 you will accept and relay mail addressed to foo.com. See
1147 description below for more information before using this
1148 feature. Also, see the KNOWNBUGS entry regarding bestmx
1151 FEATURE(`relay_based_on_MX') does not necessarily allow
1152 routing of these messages which you expect to be allowed,
1153 if route address syntax (or %-hack syntax) is used. If
1154 this is a problem, add entries to the access-table or use
1155 FEATURE(`loose_relay_check').
1158 Allows relaying if the mail sender is listed as RELAY in
1159 the access map. If an optional argument `domain' (this
1160 is the literal word `domain', not a placeholder) is given,
1161 relaying can be allowed just based on the domain portion
1162 of the sender address. This feature should only be used if
1163 absolutely necessary as the sender address can be easily
1164 forged. Use of this feature requires the "From:" tag to
1165 be used for the key in the access map; see the discussion
1166 of tags and FEATURE(`relay_mail_from') in the section on
1167 anti-spam configuration control.
1170 Allows relaying if the domain portion of the mail sender
1171 is a local host. This should only be used if absolutely
1172 necessary as it opens a window for spammers. Specifically,
1173 they can send mail to your mail server that claims to be
1174 from your domain (either directly or via a routed address),
1175 and you will go ahead and relay it out to arbitrary hosts
1178 accept_unqualified_senders
1179 Normally, MAIL FROM: commands in the SMTP session will be
1180 refused if the connection is a network connection and the
1181 sender address does not include a domain name. If your
1182 setup sends local mail unqualified (i.e., MAIL FROM: <joe>),
1183 you will need to use this feature to accept unqualified
1184 sender addresses. Setting the DaemonPortOptions modifier
1185 'u' overrides the default behavior, i.e., unqualified
1186 addresses are accepted even without this FEATURE.
1187 If this FEATURE is not used, the DaemonPortOptions modifier
1188 'f' can be used to enforce fully qualified addresses.
1190 accept_unresolvable_domains
1191 Normally, MAIL FROM: commands in the SMTP session will be
1192 refused if the host part of the argument to MAIL FROM:
1193 cannot be located in the host name service (e.g., an A or
1194 MX record in DNS). If you are inside a firewall that has
1195 only a limited view of the Internet host name space, this
1196 could cause problems. In this case you probably want to
1197 use this feature to accept all domains on input, even if
1198 they are unresolvable.
1200 access_db Turns on the access database feature. The access db gives
1201 you the ability to allow or refuse to accept mail from
1202 specified domains for administrative reasons. Moreover,
1203 it can control the behavior of sendmail in various situations.
1204 By default, the access database specification is:
1206 hash -T<TMPF> /etc/mail/access
1208 See the anti-spam configuration control section for further
1209 important information about this feature. Notice:
1210 "-T<TMPF>" is meant literal, do not replace it by anything.
1212 blacklist_recipients
1213 Turns on the ability to block incoming mail for certain
1214 recipient usernames, hostnames, or addresses. For
1215 example, you can block incoming mail to user nobody,
1216 host foo.mydomain.com, or guest@bar.mydomain.com.
1217 These specifications are put in the access db as
1218 described in the anti-spam configuration control section
1219 later in this document.
1221 delay_checks The rulesets check_mail and check_relay will not be called
1222 when a client connects or issues a MAIL command, respectively.
1223 Instead, those rulesets will be called by the check_rcpt
1224 ruleset; they will be skipped under certain circumstances.
1225 See "Delay all checks" in the anti-spam configuration control
1226 section. Note: this feature is incompatible to the versions
1229 dnsbl Turns on rejection of hosts found in an DNS based rejection
1230 list. If an argument is provided it is used as the domain
1231 in which blocked hosts are listed; otherwise it defaults to
1232 blackholes.mail-abuse.org. An explanation for an DNS based
1233 rejection list can be found at http://mail-abuse.org/rbl/.
1234 A second argument can be used to change the default error
1235 message. Without that second argument, the error message
1237 Rejected: IP-ADDRESS listed at SERVER
1238 where IP-ADDRESS and SERVER are replaced by the appropriate
1239 information. By default, temporary lookup failures are
1240 ignored. This behavior can be changed by specifying a
1241 third argument, which must be either `t' or a full error
1242 message. See the anti-spam configuration control section for
1243 an example. The dnsbl feature can be included several times
1244 to query different DNS based rejection lists. See also
1245 enhdnsbl for an enhanced version.
1247 Set the DNSBL_MAP mc option to change the default map
1248 definition from `host'. Set the DNSBL_MAP_OPT mc option
1249 to add additional options to the map specification used.
1251 Some DNS based rejection lists cause failures if asked
1252 for AAAA records. If your sendmail version is compiled
1253 with IPv6 support (NETINET6) and you experience this
1256 define(`DNSBL_MAP', `dns -R A')
1258 before the first use of this feature. Alternatively you
1259 can use enhdnsbl instead (see below). Moreover, this
1260 statement can be used to reduce the number of DNS retries,
1263 define(`DNSBL_MAP', `dns -R A -r2')
1265 See below (EDNSBL_TO) for an explanation.
1267 NOTE: The default DNS blacklist, blackholes.mail-abuse.org,
1268 is a service offered by the Mail Abuse Prevention System
1269 (MAPS). As of July 31, 2001, MAPS is a subscription
1270 service, so using that network address won't work if you
1271 haven't subscribed. Contact MAPS to subscribe
1272 (http://mail-abuse.org/).
1274 enhdnsbl Enhanced version of dnsbl (see above). Further arguments
1275 (up to 5) can be used to specify specific return values
1276 from lookups. Temporary lookup failures are ignored unless
1277 a third argument is given, which must be either `t' or a full
1278 error message. By default, any successful lookup will
1279 generate an error. Otherwise the result of the lookup is
1280 compared with the supplied argument(s), and only if a match
1281 occurs an error is generated. For example,
1283 FEATURE(`enhdnsbl', `dnsbl.example.com', `', `t', `127.0.0.2.')
1285 will reject the e-mail if the lookup returns the value
1286 ``127.0.0.2.'', or generate a 451 response if the lookup
1287 temporarily failed. The arguments can contain metasymbols
1288 as they are allowed in the LHS of rules. As the example
1289 shows, the default values are also used if an empty argument,
1290 i.e., `', is specified. This feature requires that sendmail
1291 has been compiled with the flag DNSMAP (see sendmail/README).
1293 Set the EDNSBL_TO mc option to change the DNS retry count
1294 from the default value of 5, this can be very useful when
1295 a DNS server is not responding, which in turn may cause
1296 clients to time out (an entry stating
1298 did not issue MAIL/EXPN/VRFY/ETRN
1302 lookupdotdomain Look up also .domain in the access map. This allows to
1303 match only subdomains. It does not work well with
1304 FEATURE(`relay_hosts_only'), because most lookups for
1305 subdomains are suppressed by the latter feature.
1308 Normally, if % addressing is used for a recipient, e.g.
1309 user%site@othersite, and othersite is in class {R}, the
1310 check_rcpt ruleset will strip @othersite and recheck
1311 user@site for relaying. This feature changes that
1312 behavior. It should not be needed for most installations.
1314 authinfo Provide a separate map for client side authentication
1315 information. See SMTP AUTHENTICATION for details.
1316 By default, the authinfo database specification is:
1318 hash /etc/mail/authinfo
1321 Preserve the name of the recipient host if LUSER_RELAY is
1322 used. Without this option, the domain part of the
1323 recipient address will be replaced by the host specified as
1324 LUSER_RELAY. This feature only works if the hostname is
1325 passed to the mailer (see mailer triple in op.me). Note
1326 that in the default configuration the local mailer does not
1327 receive the hostname, i.e., the mailer triple has an empty
1330 preserve_local_plus_detail
1331 Preserve the +detail portion of the address when passing
1332 address to local delivery agent. Disables alias and
1333 .forward +detail stripping (e.g., given user+detail, only
1334 that address will be looked up in the alias file; user+* and
1335 user will not be looked up). Only use if the local
1336 delivery agent in use supports +detail addressing.
1338 compat_check Enable ruleset check_compat to look up pairs of addresses
1339 with the Compat: tag -- Compat:sender<@>recipient -- in the
1340 access map. Valid values for the RHS include
1341 DISCARD silently discard recipient
1342 TEMP: return a temporary error
1343 ERROR: return a permanent error
1344 In the last two cases, a 4xy/5xy SMTP reply code should
1347 no_default_msa Don't generate the default MSA daemon, i.e.,
1348 DAEMON_OPTIONS(`Port=587,Name=MSA,M=E')
1349 To define a MSA daemon with other parameters, use this
1350 FEATURE and introduce new settings via DAEMON_OPTIONS().
1352 msp Defines config file for Message Submission Program.
1353 See sendmail/SECURITY for details and cf/cf/submit.mc how
1354 to use it. An optional argument can be used to override
1355 the default of `[localhost]' to use as host to send all
1356 e-mails to. Note that MX records will be used if the
1357 specified hostname is not in square brackets (e.g.,
1358 [hostname]). If `MSA' is specified as second argument then
1359 port 587 is used to contact the server. Example:
1361 FEATURE(`msp', `', `MSA')
1363 Some more hints about possible changes can be found below
1364 in the section MESSAGE SUBMISSION PROGRAM.
1366 Note: Due to many problems, submit.mc uses
1368 FEATURE(`msp', `[127.0.0.1]')
1370 by default. If you have a machine with IPv6 only,
1373 FEATURE(`msp', `[IPv6:::1]')
1375 If you want to continue using '[localhost]', (the behavior
1380 queuegroup A simple example how to select a queue group based
1381 on the full e-mail address or the domain of the
1382 recipient. Selection is done via entries in the
1383 access map using the tag QGRP:, for example:
1385 QGRP:example.com main
1386 QGRP:friend@some.org others
1387 QGRP:my.domain local
1389 where "main", "others", and "local" are names of
1390 queue groups. If an argument is specified, it is used
1391 as default queue group.
1393 Note: please read the warning in doc/op/op.me about
1394 queue groups and possible queue manipulations.
1400 Some things just can't be called features. To make this clear,
1401 they go in the hack subdirectory and are referenced using the HACK
1402 macro. These will tend to be site-dependent. The release
1403 includes the Berkeley-dependent "cssubdomain" hack (that makes
1404 sendmail accept local names in either Berkeley.EDU or CS.Berkeley.EDU;
1405 this is intended as a short-term aid while moving hosts into
1409 +--------------------+
1410 | SITE CONFIGURATION |
1411 +--------------------+
1413 *****************************************************
1414 * This section is really obsolete, and is preserved *
1415 * only for back compatibility. You should plan on *
1416 * using mailertables for new installations. In *
1417 * particular, it doesn't work for the newer forms *
1418 * of UUCP mailers, such as uucp-uudom. *
1419 *****************************************************
1421 Complex sites will need more local configuration information, such as
1422 lists of UUCP hosts they speak with directly. This can get a bit more
1423 tricky. For an example of a "complex" site, see cf/ucbvax.mc.
1425 The SITECONFIG macro allows you to indirectly reference site-dependent
1426 configuration information stored in the siteconfig subdirectory. For
1429 SITECONFIG(`uucp.ucbvax', `ucbvax', `U')
1431 reads the file uucp.ucbvax for local connection information. The
1432 second parameter is the local name (in this case just "ucbvax" since
1433 it is locally connected, and hence a UUCP hostname). The third
1434 parameter is the name of both a macro to store the local name (in
1435 this case, {U}) and the name of the class (e.g., {U}) in which to store
1436 the host information read from the file. Another SITECONFIG line reads
1438 SITECONFIG(`uucp.ucbarpa', `ucbarpa.Berkeley.EDU', `W')
1440 This says that the file uucp.ucbarpa contains the list of UUCP sites
1441 connected to ucbarpa.Berkeley.EDU. Class {W} will be used to
1442 store this list, and $W is defined to be ucbarpa.Berkeley.EDU, that
1443 is, the name of the relay to which the hosts listed in uucp.ucbarpa
1444 are connected. [The machine ucbarpa is gone now, but this
1445 out-of-date configuration file has been left around to demonstrate
1446 how you might do this.]
1448 Note that the case of SITECONFIG with a third parameter of ``U'' is
1449 special; the second parameter is assumed to be the UUCP name of the
1450 local site, rather than the name of a remote site, and the UUCP name
1451 is entered into class {w} (the list of local hostnames) as $U.UUCP.
1453 The siteconfig file (e.g., siteconfig/uucp.ucbvax.m4) contains nothing
1454 more than a sequence of SITE macros describing connectivity. For
1460 The second example demonstrates that you can use two names on the
1461 same line; these are usually aliases for the same host (or are at
1462 least in the same company).
1465 +--------------------+
1466 | USING UUCP MAILERS |
1467 +--------------------+
1469 It's hard to get UUCP mailers right because of the extremely ad hoc
1470 nature of UUCP addressing. These config files are really designed
1471 for domain-based addressing, even for UUCP sites.
1473 There are four UUCP mailers available. The choice of which one to
1474 use is partly a matter of local preferences and what is running at
1475 the other end of your UUCP connection. Unlike good protocols that
1476 define what will go over the wire, UUCP uses the policy that you
1477 should do what is right for the other end; if they change, you have
1478 to change. This makes it hard to do the right thing, and discourages
1479 people from updating their software. In general, if you can avoid
1482 The major choice is whether to go for a domainized scheme or a
1483 non-domainized scheme. This depends entirely on what the other
1484 end will recognize. If at all possible, you should encourage the
1485 other end to go to a domain-based system -- non-domainized addresses
1486 don't work entirely properly.
1488 The four mailers are:
1490 uucp-old (obsolete name: "uucp")
1491 This is the oldest, the worst (but the closest to UUCP) way of
1492 sending messages accros UUCP connections. It does bangify
1493 everything and prepends $U (your UUCP name) to the sender's
1494 address (which can already be a bang path itself). It can
1495 only send to one address at a time, so it spends a lot of
1496 time copying duplicates of messages. Avoid this if at all
1499 uucp-new (obsolete name: "suucp")
1500 The same as above, except that it assumes that in one rmail
1501 command you can specify several recipients. It still has a
1502 lot of other problems.
1505 This UUCP mailer keeps everything as domain addresses.
1506 Basically, it uses the SMTP mailer rewriting rules. This mailer
1507 is only included if MAILER(`smtp') is specified before
1510 Unfortunately, a lot of UUCP mailer transport agents require
1511 bangified addresses in the envelope, although you can use
1512 domain-based addresses in the message header. (The envelope
1513 shows up as the From_ line on UNIX mail.) So....
1516 This is a cross between uucp-new (for the envelope addresses)
1517 and uucp-dom (for the header addresses). It bangifies the
1518 envelope sender (From_ line in messages) without adding the
1519 local hostname, unless there is no host name on the address
1520 at all (e.g., "wolf") or the host component is a UUCP host name
1521 instead of a domain name ("somehost!wolf" instead of
1522 "some.dom.ain!wolf"). This is also included only if MAILER(`smtp')
1523 is also specified earlier.
1527 On host grasp.insa-lyon.fr (UUCP host name "grasp"), the following
1528 summarizes the sender rewriting for various mailers.
1530 Mailer sender rewriting in the envelope
1531 ------ ------ -------------------------
1532 uucp-{old,new} wolf grasp!wolf
1533 uucp-dom wolf wolf@grasp.insa-lyon.fr
1534 uucp-uudom wolf grasp.insa-lyon.fr!wolf
1536 uucp-{old,new} wolf@fr.net grasp!fr.net!wolf
1537 uucp-dom wolf@fr.net wolf@fr.net
1538 uucp-uudom wolf@fr.net fr.net!wolf
1540 uucp-{old,new} somehost!wolf grasp!somehost!wolf
1541 uucp-dom somehost!wolf somehost!wolf@grasp.insa-lyon.fr
1542 uucp-uudom somehost!wolf grasp.insa-lyon.fr!somehost!wolf
1544 If you are using one of the domainized UUCP mailers, you really want
1545 to convert all UUCP addresses to domain format -- otherwise, it will
1546 do it for you (and probably not the way you expected). For example,
1547 if you have the address foo!bar!baz (and you are not sending to foo),
1548 the heuristics will add the @uucp.relay.name or @local.host.name to
1549 this address. However, if you map foo to foo.host.name first, it
1550 will not add the local hostname. You can do this using the uucpdomain
1554 +-------------------+
1555 | TWEAKING RULESETS |
1556 +-------------------+
1558 For more complex configurations, you can define special rules.
1559 The macro LOCAL_RULE_3 introduces rules that are used in canonicalizing
1560 the names. Any modifications made here are reflected in the header.
1562 A common use is to convert old UUCP addresses to SMTP addresses using
1563 the UUCPSMTP macro. For example:
1566 UUCPSMTP(`decvax', `decvax.dec.com')
1567 UUCPSMTP(`research', `research.att.com')
1569 will cause addresses of the form "decvax!user" and "research!user"
1570 to be converted to "user@decvax.dec.com" and "user@research.att.com"
1573 This could also be used to look up hosts in a database map:
1576 R$* < @ $+ > $* $: $1 < @ $(hostmap $2 $) > $3
1578 This map would be defined in the LOCAL_CONFIG portion, as shown below.
1580 Similarly, LOCAL_RULE_0 can be used to introduce new parsing rules.
1581 For example, new rules are needed to parse hostnames that you accept
1582 via MX records. For example, you might have:
1585 R$+ <@ host.dom.ain.> $#uucp $@ cnmat $: $1 < @ host.dom.ain.>
1587 You would use this if you had installed an MX record for cnmat.Berkeley.EDU
1588 pointing at this host; this rule catches the message and forwards it on
1591 You can also tweak rulesets 1 and 2 using LOCAL_RULE_1 and LOCAL_RULE_2.
1592 These rulesets are normally empty.
1594 A similar macro is LOCAL_CONFIG. This introduces lines added after the
1595 boilerplate option setting but before rulesets. Do not declare rulesets in
1596 the LOCAL_CONFIG section. It can be used to declare local database maps or
1597 whatever. For example:
1600 Khostmap hash /etc/mail/hostmap
1601 Kyplocal nis -m hosts.byname
1604 +---------------------------+
1605 | MASQUERADING AND RELAYING |
1606 +---------------------------+
1608 You can have your host masquerade as another using
1610 MASQUERADE_AS(`host.domain')
1612 This causes mail being sent to be labeled as coming from the
1613 indicated host.domain, rather than $j. One normally masquerades as
1614 one of one's own subdomains (for example, it's unlikely that
1615 Berkeley would choose to masquerade as an MIT site). This
1616 behaviour is modified by a plethora of FEATUREs; in particular, see
1617 masquerade_envelope, allmasquerade, limited_masquerade, and
1618 masquerade_entire_domain.
1620 The masquerade name is not normally canonified, so it is important
1621 that it be your One True Name, that is, fully qualified and not a
1622 CNAME. However, if you use a CNAME, the receiving side may canonify
1623 it for you, so don't think you can cheat CNAME mapping this way.
1625 Normally the only addresses that are masqueraded are those that come
1626 from this host (that is, are either unqualified or in class {w}, the list
1627 of local domain names). You can augment this list, which is realized
1630 MASQUERADE_DOMAIN(`otherhost.domain')
1632 The effect of this is that although mail to user@otherhost.domain
1633 will not be delivered locally, any mail including any user@otherhost.domain
1634 will, when relayed, be rewritten to have the MASQUERADE_AS address.
1635 This can be a space-separated list of names.
1637 If these names are in a file, you can use
1639 MASQUERADE_DOMAIN_FILE(`filename')
1641 to read the list of names from the indicated file (i.e., to add
1642 elements to class {M}).
1644 To exempt hosts or subdomains from being masqueraded, you can use
1646 MASQUERADE_EXCEPTION(`host.domain')
1648 This can come handy if you want to masquerade a whole domain
1649 except for one (or a few) host(s). If these names are in a file,
1652 MASQUERADE_EXCEPTION_FILE(`filename')
1654 Normally only header addresses are masqueraded. If you want to
1655 masquerade the envelope as well, use
1657 FEATURE(`masquerade_envelope')
1659 There are always users that need to be "exposed" -- that is, their
1660 internal site name should be displayed instead of the masquerade name.
1661 Root is an example (which has been "exposed" by default prior to 8.10).
1662 You can add users to this list using
1664 EXPOSED_USER(`usernames')
1666 This adds users to class {E}; you could also use
1668 EXPOSED_USER_FILE(`filename')
1670 You can also arrange to relay all unqualified names (that is, names
1671 without @host) to a relay host. For example, if you have a central
1672 email server, you might relay to that host so that users don't have
1673 to have .forward files or aliases. You can do this using
1675 define(`LOCAL_RELAY', `mailer:hostname')
1677 The ``mailer:'' can be omitted, in which case the mailer defaults to
1678 "relay". There are some user names that you don't want relayed, perhaps
1679 because of local aliases. A common example is root, which may be
1680 locally aliased. You can add entries to this list using
1682 LOCAL_USER(`usernames')
1684 This adds users to class {L}; you could also use
1686 LOCAL_USER_FILE(`filename')
1688 If you want all incoming mail sent to a centralized hub, as for a
1689 shared /var/spool/mail scheme, use
1691 define(`MAIL_HUB', `mailer:hostname')
1693 Again, ``mailer:'' defaults to "relay". If you define both LOCAL_RELAY
1694 and MAIL_HUB _AND_ you have FEATURE(`stickyhost'), unqualified names will
1695 be sent to the LOCAL_RELAY and other local names will be sent to MAIL_HUB.
1696 Note: there is a (long standing) bug which keeps this combination from
1697 working for addresses of the form user+detail.
1698 Names in class {L} will be delivered locally, so you MUST have aliases or
1699 .forward files for them.
1701 For example, if you are on machine mastodon.CS.Berkeley.EDU and you have
1702 FEATURE(`stickyhost'), the following combinations of settings will have the
1705 email sent to.... eric eric@mastodon.CS.Berkeley.EDU
1707 LOCAL_RELAY set to mail.CS.Berkeley.EDU (delivered locally)
1708 mail.CS.Berkeley.EDU (no local aliasing) (aliasing done)
1710 MAIL_HUB set to mammoth.CS.Berkeley.EDU mammoth.CS.Berkeley.EDU
1711 mammoth.CS.Berkeley.EDU (aliasing done) (aliasing done)
1713 Both LOCAL_RELAY and mail.CS.Berkeley.EDU mammoth.CS.Berkeley.EDU
1714 MAIL_HUB set as above (no local aliasing) (aliasing done)
1716 If you do not have FEATURE(`stickyhost') set, then LOCAL_RELAY and
1717 MAIL_HUB act identically, with MAIL_HUB taking precedence.
1719 If you want all outgoing mail to go to a central relay site, define
1720 SMART_HOST as well. Briefly:
1722 LOCAL_RELAY applies to unqualified names (e.g., "eric").
1723 MAIL_HUB applies to names qualified with the name of the
1724 local host (e.g., "eric@mastodon.CS.Berkeley.EDU").
1725 SMART_HOST applies to names qualified with other hosts or
1726 bracketed addresses (e.g., "eric@mastodon.CS.Berkeley.EDU"
1727 or "eric@[127.0.0.1]").
1729 However, beware that other relays (e.g., UUCP_RELAY, BITNET_RELAY,
1730 DECNET_RELAY, and FAX_RELAY) take precedence over SMART_HOST, so if you
1731 really want absolutely everything to go to a single central site you will
1732 need to unset all the other relays -- or better yet, find or build a
1733 minimal config file that does this.
1735 For duplicate suppression to work properly, the host name is best
1736 specified with a terminal dot:
1738 define(`MAIL_HUB', `host.domain.')
1739 note the trailing dot ---^
1742 +-------------------------------------------+
1743 | USING LDAP FOR ALIASES, MAPS, AND CLASSES |
1744 +-------------------------------------------+
1746 LDAP can be used for aliases, maps, and classes by either specifying your
1747 own LDAP map specification or using the built-in default LDAP map
1748 specification. The built-in default specifications all provide lookups
1749 which match against either the machine's fully qualified hostname (${j}) or
1750 a "cluster". The cluster allows you to share LDAP entries among a large
1751 number of machines without having to enter each of the machine names into
1752 each LDAP entry. To set the LDAP cluster name to use for a particular
1753 machine or set of machines, set the confLDAP_CLUSTER m4 variable to a
1754 unique name. For example:
1756 define(`confLDAP_CLUSTER', `Servers')
1758 Here, the word `Servers' will be the cluster name. As an example, assume
1759 that smtp.sendmail.org, etrn.sendmail.org, and mx.sendmail.org all belong
1760 to the Servers cluster.
1762 Some of the LDAP LDIF examples below show use of the Servers cluster.
1763 Every entry must have either a sendmailMTAHost or sendmailMTACluster
1764 attribute or it will be ignored. Be careful as mixing clusters and
1765 individual host records can have surprising results (see the CAUTION
1768 See the file cf/sendmail.schema for the actual LDAP schemas. Note that
1769 this schema (and therefore the lookups and examples below) is experimental
1770 at this point as it has had little public review. Therefore, it may change
1771 in future versions. Feedback via sendmail@sendmail.org is encouraged.
1777 The ALIAS_FILE (O AliasFile) option can be set to use LDAP for alias
1778 lookups. To use the default schema, simply use:
1780 define(`ALIAS_FILE', `ldap:')
1782 By doing so, you will use the default schema which expands to a map
1783 declared as follows:
1785 ldap -k (&(objectClass=sendmailMTAAliasObject)
1786 (sendmailMTAAliasGrouping=aliases)
1787 (|(sendmailMTACluster=${sendmailMTACluster})
1788 (sendmailMTAHost=$j))
1789 (sendmailMTAKey=%0))
1790 -v sendmailMTAAliasValue
1792 NOTE: The macros shown above ${sendmailMTACluster} and $j are not actually
1793 used when the binary expands the `ldap:' token as the AliasFile option is
1794 not actually macro-expanded when read from the sendmail.cf file.
1796 Example LDAP LDIF entries might be:
1798 dn: sendmailMTAKey=sendmail-list, dc=sendmail, dc=org
1799 objectClass: sendmailMTA
1800 objectClass: sendmailMTAAlias
1801 objectClass: sendmailMTAAliasObject
1802 sendmailMTAAliasGrouping: aliases
1803 sendmailMTAHost: etrn.sendmail.org
1804 sendmailMTAKey: sendmail-list
1805 sendmailMTAAliasValue: ca@example.org
1806 sendmailMTAAliasValue: eric
1807 sendmailMTAAliasValue: gshapiro@example.com
1809 dn: sendmailMTAKey=owner-sendmail-list, dc=sendmail, dc=org
1810 objectClass: sendmailMTA
1811 objectClass: sendmailMTAAlias
1812 objectClass: sendmailMTAAliasObject
1813 sendmailMTAAliasGrouping: aliases
1814 sendmailMTAHost: etrn.sendmail.org
1815 sendmailMTAKey: owner-sendmail-list
1816 sendmailMTAAliasValue: eric
1818 dn: sendmailMTAKey=postmaster, dc=sendmail, dc=org
1819 objectClass: sendmailMTA
1820 objectClass: sendmailMTAAlias
1821 objectClass: sendmailMTAAliasObject
1822 sendmailMTAAliasGrouping: aliases
1823 sendmailMTACluster: Servers
1824 sendmailMTAKey: postmaster
1825 sendmailMTAAliasValue: eric
1827 Here, the aliases sendmail-list and owner-sendmail-list will be available
1828 only on etrn.sendmail.org but the postmaster alias will be available on
1829 every machine in the Servers cluster (including etrn.sendmail.org).
1831 CAUTION: aliases are additive so that entries like these:
1833 dn: sendmailMTAKey=bob, dc=sendmail, dc=org
1834 objectClass: sendmailMTA
1835 objectClass: sendmailMTAAlias
1836 objectClass: sendmailMTAAliasObject
1837 sendmailMTAAliasGrouping: aliases
1838 sendmailMTACluster: Servers
1840 sendmailMTAAliasValue: eric
1842 dn: sendmailMTAKey=bobetrn, dc=sendmail, dc=org
1843 objectClass: sendmailMTA
1844 objectClass: sendmailMTAAlias
1845 objectClass: sendmailMTAAliasObject
1846 sendmailMTAAliasGrouping: aliases
1847 sendmailMTAHost: etrn.sendmail.org
1849 sendmailMTAAliasValue: gshapiro
1851 would mean that on all of the hosts in the cluster, mail to bob would go to
1852 eric EXCEPT on etrn.sendmail.org in which case it would go to BOTH eric and
1855 If you prefer not to use the default LDAP schema for your aliases, you can
1856 specify the map parameters when setting ALIAS_FILE. For example:
1858 define(`ALIAS_FILE', `ldap:-k (&(objectClass=mailGroup)(mail=%0)) -v mgrpRFC822MailMember')
1864 FEATURE()'s which take an optional map definition argument (e.g., access,
1865 mailertable, virtusertable, etc.) can instead take the special keyword
1868 FEATURE(`access_db', `LDAP')
1869 FEATURE(`virtusertable', `LDAP')
1871 When this keyword is given, that map will use LDAP lookups consisting of
1872 the objectClass sendmailMTAClassObject, the attribute sendmailMTAMapName
1873 with the map name, a search attribute of sendmailMTAKey, and the value
1874 attribute sendmailMTAMapValue.
1876 The values for sendmailMTAMapName are:
1878 FEATURE() sendmailMTAMapName
1879 --------- ------------------
1884 genericstable generics
1886 uucpdomain uucpdomain
1887 virtusertable virtuser
1889 For example, FEATURE(`mailertable', `LDAP') would use the map definition:
1891 Kmailertable ldap -k (&(objectClass=sendmailMTAMapObject)
1892 (sendmailMTAMapName=mailer)
1893 (|(sendmailMTACluster=${sendmailMTACluster})
1894 (sendmailMTAHost=$j))
1895 (sendmailMTAKey=%0))
1896 -1 -v sendmailMTAMapValue
1898 An example LDAP LDIF entry using this map might be:
1900 dn: sendmailMTAMapName=mailer, dc=sendmail, dc=org
1901 objectClass: sendmailMTA
1902 objectClass: sendmailMTAMap
1903 sendmailMTACluster: Servers
1904 sendmailMTAMapName: mailer
1906 dn: sendmailMTAKey=example.com, sendmailMTAMapName=mailer, dc=sendmail, dc=org
1907 objectClass: sendmailMTA
1908 objectClass: sendmailMTAMap
1909 objectClass: sendmailMTAMapObject
1910 sendmailMTAMapName: mailer
1911 sendmailMTACluster: Servers
1912 sendmailMTAKey: example.com
1913 sendmailMTAMapValue: relay:[smtp.example.com]
1915 CAUTION: If your LDAP database contains the record above and *ALSO* a host
1916 specific record such as:
1918 dn: sendmailMTAKey=example.com@etrn, sendmailMTAMapName=mailer, dc=sendmail, dc=org
1919 objectClass: sendmailMTA
1920 objectClass: sendmailMTAMap
1921 objectClass: sendmailMTAMapObject
1922 sendmailMTAMapName: mailer
1923 sendmailMTAHost: etrn.sendmail.org
1924 sendmailMTAKey: example.com
1925 sendmailMTAMapValue: relay:[mx.example.com]
1927 then these entries will give unexpected results. When the lookup is done
1928 on etrn.sendmail.org, the effect is that there is *NO* match at all as maps
1929 require a single match. Since the host etrn.sendmail.org is also in the
1930 Servers cluster, LDAP would return two answers for the example.com map key
1931 in which case sendmail would treat this as no match at all.
1933 If you prefer not to use the default LDAP schema for your maps, you can
1934 specify the map parameters when using the FEATURE(). For example:
1936 FEATURE(`access_db', `ldap:-1 -k (&(objectClass=mapDatabase)(key=%0)) -v value')
1942 Normally, classes can be filled via files or programs. As of 8.12, they
1943 can also be filled via map lookups using a new syntax:
1945 F{ClassName}mapkey@mapclass:mapspec
1947 mapkey is optional and if not provided the map key will be empty. This can
1948 be used with LDAP to read classes from LDAP. Note that the lookup is only
1949 done when sendmail is initially started. Use the special value `@LDAP' to
1950 use the default LDAP schema. For example:
1952 RELAY_DOMAIN_FILE(`@LDAP')
1954 would put all of the attribute sendmailMTAClassValue values of LDAP records
1955 with objectClass sendmailMTAClass and an attribute sendmailMTAClassName of
1956 'R' into class $={R}. In other words, it is equivalent to the LDAP map
1959 F{R}@ldap:-k (&(objectClass=sendmailMTAClass)
1960 (sendmailMTAClassName=R)
1961 (|(sendmailMTACluster=${sendmailMTACluster})
1962 (sendmailMTAHost=$j)))
1963 -v sendmailMTAClassValue
1965 NOTE: The macros shown above ${sendmailMTACluster} and $j are not actually
1966 used when the binary expands the `@LDAP' token as class declarations are
1967 not actually macro-expanded when read from the sendmail.cf file.
1969 This can be used with class related commands such as RELAY_DOMAIN_FILE(),
1970 MASQUERADE_DOMAIN_FILE(), etc:
1972 Command sendmailMTAClassName
1973 ------- --------------------
1974 CANONIFY_DOMAIN_FILE() Canonify
1975 EXPOSED_USER_FILE() E
1976 GENERICS_DOMAIN_FILE() G
1977 LDAPROUTE_DOMAIN_FILE() LDAPRoute
1978 LDAPROUTE_EQUIVALENT_FILE() LDAPRouteEquiv
1980 MASQUERADE_DOMAIN_FILE() M
1981 MASQUERADE_EXCEPTION_FILE() N
1982 RELAY_DOMAIN_FILE() R
1983 VIRTUSER_DOMAIN_FILE() VirtHost
1985 You can also add your own as any 'F'ile class of the form:
1989 will use "ClassName" for the sendmailMTAClassName.
1991 An example LDAP LDIF entry would look like:
1993 dn: sendmailMTAClassName=R, dc=sendmail, dc=org
1994 objectClass: sendmailMTA
1995 objectClass: sendmailMTAClass
1996 sendmailMTACluster: Servers
1997 sendmailMTAClassName: R
1998 sendmailMTAClassValue: sendmail.org
1999 sendmailMTAClassValue: example.com
2000 sendmailMTAClassValue: 10.56.23
2002 CAUTION: If your LDAP database contains the record above and *ALSO* a host
2003 specific record such as:
2005 dn: sendmailMTAClassName=R@etrn.sendmail.org, dc=sendmail, dc=org
2006 objectClass: sendmailMTA
2007 objectClass: sendmailMTAClass
2008 sendmailMTAHost: etrn.sendmail.org
2009 sendmailMTAClassName: R
2010 sendmailMTAClassValue: example.com
2012 the result will be similar to the aliases caution above. When the lookup
2013 is done on etrn.sendmail.org, $={R} would contain all of the entries (from
2014 both the cluster match and the host match). In other words, the effective
2017 If you prefer not to use the default LDAP schema for your classes, you can
2018 specify the map parameters when using the class command. For example:
2020 VIRTUSER_DOMAIN_FILE(`@ldap:-k (&(objectClass=virtHosts)(host=*)) -v host')
2022 Remember, macros can not be used in a class declaration as the binary does
2030 FEATURE(`ldap_routing') can be used to implement the IETF Internet Draft
2031 LDAP Schema for Intranet Mail Routing
2032 (draft-lachman-laser-ldap-mail-routing-01). This feature enables
2033 LDAP-based rerouting of a particular address to either a different host
2034 or a different address. The LDAP lookup is first attempted on the full
2035 address (e.g., user@example.com) and then on the domain portion
2036 (e.g., @example.com). Be sure to setup your domain for LDAP routing using
2037 LDAPROUTE_DOMAIN(), e.g.:
2039 LDAPROUTE_DOMAIN(`example.com')
2041 Additionally, you can specify equivalent domains for LDAP routing using
2042 LDAPROUTE_EQUIVALENT() and LDAPROUTE_EQUIVALENT_FILE(). 'Equivalent'
2043 hostnames are mapped to $M (the masqueraded hostname for the server) before
2044 the LDAP query. For example, if the mail is addressed to
2045 user@host1.example.com, normally the LDAP lookup would only be done for
2046 'user@host1.example.com' and '@host1.example.com'. However, if
2047 LDAPROUTE_EQUIVALENT(`host1.example.com') is used, the lookups would also be
2048 done on 'user@example.com' and '@example.com' after attempting the
2049 host1.example.com lookups.
2051 By default, the feature will use the schemas as specified in the draft
2052 and will not reject addresses not found by the LDAP lookup. However,
2053 this behavior can be changed by giving additional arguments to the FEATURE()
2056 FEATURE(`ldap_routing', <mailHost>, <mailRoutingAddress>, <bounce>, <detail>)
2058 where <mailHost> is a map definition describing how to lookup an alternative
2059 mail host for a particular address; <mailRoutingAddress> is a map definition
2060 describing how to lookup an alternative address for a particular address;
2061 the <bounce> argument, if present and not the word "passthru", dictates
2062 that mail should be bounced if neither a mailHost nor mailRoutingAddress
2063 is found; and <detail> indicates what actions to take if the address
2064 contains +detail information -- `strip' tries the lookup with the +detail
2065 and if no matches are found, strips the +detail and tries the lookup again;
2066 `preserve', does the same as `strip' but if a mailRoutingAddress match is
2067 found, the +detail information is copied to the new address.
2069 The default <mailHost> map definition is:
2071 ldap -1 -T<TMPF> -v mailHost -k (&(objectClass=inetLocalMailRecipient)
2072 (mailLocalAddress=%0))
2074 The default <mailRoutingAddress> map definition is:
2076 ldap -1 -T<TMPF> -v mailRoutingAddress
2077 -k (&(objectClass=inetLocalMailRecipient)
2078 (mailLocalAddress=%0))
2080 Note that neither includes the LDAP server hostname (-h server) or base DN
2081 (-b o=org,c=COUNTRY), both necessary for LDAP queries. It is presumed that
2082 your .mc file contains a setting for the confLDAP_DEFAULT_SPEC option with
2083 these settings. If this is not the case, the map definitions should be
2084 changed as described above. The "-T<TMPF>" is required in any user
2085 specified map definition to catch temporary errors.
2087 The following possibilities exist as a result of an LDAP lookup on an
2090 mailHost is mailRoutingAddress is Results in
2091 ----------- --------------------- ----------
2092 set to a set mail delivered to
2093 "local" host mailRoutingAddress
2095 set to a not set delivered to
2096 "local" host original address
2098 set to a set mailRoutingAddress
2099 remote host relayed to mailHost
2101 set to a not set original address
2102 remote host relayed to mailHost
2104 not set set mail delivered to
2107 not set not set delivered to
2108 original address *OR*
2109 bounced as unknown user
2111 The term "local" host above means the host specified is in class {w}. If
2112 the result would mean sending the mail to a different host, that host is
2113 looked up in the mailertable before delivery.
2115 Note that the last case depends on whether the third argument is given
2116 to the FEATURE() command. The default is to deliver the message to the
2119 The LDAP entries should be set up with an objectClass of
2120 inetLocalMailRecipient and the address be listed in a mailLocalAddress
2121 attribute. If present, there must be only one mailHost attribute and it
2122 must contain a fully qualified host name as its value. Similarly, if
2123 present, there must be only one mailRoutingAddress attribute and it must
2124 contain an RFC 822 compliant address. Some example LDAP records (in LDIF
2127 dn: uid=tom, o=example.com, c=US
2128 objectClass: inetLocalMailRecipient
2129 mailLocalAddress: tom@example.com
2130 mailRoutingAddress: thomas@mailhost.example.com
2132 This would deliver mail for tom@example.com to thomas@mailhost.example.com.
2134 dn: uid=dick, o=example.com, c=US
2135 objectClass: inetLocalMailRecipient
2136 mailLocalAddress: dick@example.com
2137 mailHost: eng.example.com
2139 This would relay mail for dick@example.com to the same address but redirect
2140 the mail to MX records listed for the host eng.example.com (unless the
2141 mailertable overrides).
2143 dn: uid=harry, o=example.com, c=US
2144 objectClass: inetLocalMailRecipient
2145 mailLocalAddress: harry@example.com
2146 mailHost: mktmail.example.com
2147 mailRoutingAddress: harry@mkt.example.com
2149 This would relay mail for harry@example.com to the MX records listed for
2150 the host mktmail.example.com using the new address harry@mkt.example.com
2151 when talking to that host.
2153 dn: uid=virtual.example.com, o=example.com, c=US
2154 objectClass: inetLocalMailRecipient
2155 mailLocalAddress: @virtual.example.com
2156 mailHost: server.example.com
2157 mailRoutingAddress: virtual@example.com
2159 This would send all mail destined for any username @virtual.example.com to
2160 the machine server.example.com's MX servers and deliver to the address
2161 virtual@example.com on that relay machine.
2164 +---------------------------------+
2165 | ANTI-SPAM CONFIGURATION CONTROL |
2166 +---------------------------------+
2168 The primary anti-spam features available in sendmail are:
2170 * Relaying is denied by default.
2171 * Better checking on sender information.
2175 Relaying (transmission of messages from a site outside your host (class
2176 {w}) to another site except yours) is denied by default. Note that this
2177 changed in sendmail 8.9; previous versions allowed relaying by default.
2178 If you really want to revert to the old behaviour, you will need to use
2179 FEATURE(`promiscuous_relay'). You can allow certain domains to relay
2180 through your server by adding their domain name or IP address to class
2181 {R} using RELAY_DOMAIN() and RELAY_DOMAIN_FILE() or via the access database
2182 (described below). Note that IPv6 addresses must be prefaced with "IPv6:".
2183 The file consists (like any other file based class) of entries listed on
2184 separate lines, e.g.,
2189 IPv6:2002:c0a8:51d2::23f4
2193 Notice: the last entry allows relaying for connections via a UNIX
2194 socket to the MTA/MSP. This might be necessary if your configuration
2195 doesn't allow relaying by other means in that case, e.g., by having
2196 localhost.$m in class {R} (make sure $m is not just a top level
2201 FEATURE(`relay_entire_domain')
2203 then any host in any of your local domains (that is, class {m})
2204 will be relayed (that is, you will accept mail either to or from any
2205 host in your domain).
2207 You can also allow relaying based on the MX records of the host
2208 portion of an incoming recipient address by using
2210 FEATURE(`relay_based_on_MX')
2212 For example, if your server receives a recipient of user@domain.com
2213 and domain.com lists your server in its MX records, the mail will be
2214 accepted for relay to domain.com. This feature may cause problems
2215 if MX lookups for the recipient domain are slow or time out. In that
2216 case, mail will be temporarily rejected. It is usually better to
2217 maintain a list of hosts/domains for which the server acts as relay.
2218 Note also that this feature will stop spammers from using your host
2219 to relay spam but it will not stop outsiders from using your server
2220 as a relay for their site (that is, they set up an MX record pointing
2221 to your mail server, and you will relay mail addressed to them
2222 without any prior arrangement). Along the same lines,
2224 FEATURE(`relay_local_from')
2226 will allow relaying if the sender specifies a return path (i.e.
2227 MAIL FROM: <user@domain>) domain which is a local domain. This is a
2228 dangerous feature as it will allow spammers to spam using your mail
2229 server by simply specifying a return address of user@your.domain.com.
2230 It should not be used unless absolutely necessary.
2231 A slightly better solution is
2233 FEATURE(`relay_mail_from')
2235 which allows relaying if the mail sender is listed as RELAY in the
2236 access map. If an optional argument `domain' (this is the literal
2237 word `domain', not a placeholder) is given, the domain portion of
2238 the mail sender is also checked to allowing relaying. This option
2239 only works together with the tag From: for the LHS of the access
2240 map entries (see below: Finer control...). This feature allows
2241 spammers to abuse your mail server by specifying a return address
2242 that you enabled in your access file. This may be harder to figure
2243 out for spammers, but it should not be used unless necessary.
2244 Instead use SMTP AUTH or STARTTLS to allow relaying for roaming
2248 If source routing is used in the recipient address (e.g.,
2249 RCPT TO: <user%site.com@othersite.com>), sendmail will check
2250 user@site.com for relaying if othersite.com is an allowed relay host
2251 in either class {R}, class {m} if FEATURE(`relay_entire_domain') is used,
2252 or the access database if FEATURE(`access_db') is used. To prevent
2253 the address from being stripped down, use:
2255 FEATURE(`loose_relay_check')
2257 If you think you need to use this feature, you probably do not. This
2258 should only be used for sites which have no control over the addresses
2259 that they provide a gateway for. Use this FEATURE with caution as it
2260 can allow spammers to relay through your server if not setup properly.
2262 NOTICE: It is possible to relay mail through a system which the anti-relay
2263 rules do not prevent: the case of a system that does use FEATURE(`nouucp',
2264 `nospecial') (system A) and relays local messages to a mail hub (e.g., via
2265 LOCAL_RELAY or LUSER_RELAY) (system B). If system B doesn't use
2266 FEATURE(`nouucp') at all, addresses of the form
2267 <example.net!user@local.host> would be relayed to <user@example.net>.
2268 System A doesn't recognize `!' as an address separator and therefore
2269 forwards it to the mail hub which in turns relays it because it came from
2270 a trusted local host. So if a mailserver allows UUCP (bang-format)
2271 addresses, all systems from which it allows relaying should do the same
2272 or reject those addresses.
2274 As of 8.9, sendmail will refuse mail if the MAIL FROM: parameter has
2275 an unresolvable domain (i.e., one that DNS, your local name service,
2276 or special case rules in ruleset 3 cannot locate). This also applies
2277 to addresses that use domain literals, e.g., <user@[1.2.3.4]>, if the
2278 IP address can't be mapped to a host name. If you want to continue
2279 to accept such domains, e.g., because you are inside a firewall that
2280 has only a limited view of the Internet host name space (note that you
2281 will not be able to return mail to them unless you have some "smart
2282 host" forwarder), use
2284 FEATURE(`accept_unresolvable_domains')
2286 Alternatively, you can allow specific addresses by adding them to
2287 the access map, e.g.,
2289 From:unresolvable.domain OK
2293 Notice: domains which are temporarily unresolvable are (temporarily)
2294 rejected with a 451 reply code. If those domains should be accepted
2295 (which is discouraged) then you can use
2300 sendmail will also refuse mail if the MAIL FROM: parameter is not
2301 fully qualified (i.e., contains a domain as well as a user). If you
2302 want to continue to accept such senders, use
2304 FEATURE(`accept_unqualified_senders')
2306 Setting the DaemonPortOptions modifier 'u' overrides the default behavior,
2307 i.e., unqualified addresses are accepted even without this FEATURE. If
2308 this FEATURE is not used, the DaemonPortOptions modifier 'f' can be used
2309 to enforce fully qualified domain names.
2311 An ``access'' database can be created to accept or reject mail from
2312 selected domains. For example, you may choose to reject all mail
2313 originating from known spammers. To enable such a database, use
2315 FEATURE(`access_db')
2317 Notice: the access database is applied to the envelope addresses
2318 and the connection information, not to the header.
2320 The FEATURE macro can accept as second parameter the key file
2321 definition for the database; for example
2323 FEATURE(`access_db', `hash -T<TMPF> /etc/mail/access_map')
2325 Notice: If a second argument is specified it must contain the option
2326 `-T<TMPF>' as shown above. The optional third and fourth parameters
2327 may be `skip' or `lookupdotdomain'. The former enables SKIP as
2328 value part (see below), the latter is another way to enable the
2329 feature of the same name (see above).
2331 Remember, since /etc/mail/access is a database, after creating the text
2332 file as described below, you must use makemap to create the database
2335 makemap hash /etc/mail/access < /etc/mail/access
2337 The table itself uses e-mail addresses, domain names, and network
2338 numbers as keys. Note that IPv6 addresses must be prefaced with "IPv6:".
2341 spammer@aol.com REJECT
2342 cyberspammer.com REJECT
2345 IPv6:2002:c0a8:02c7 RELAY
2346 IPv6:2002:c0a8:51d2::23f4 REJECT
2348 would refuse mail from spammer@aol.com, any user from cyberspammer.com
2349 (or any host within the cyberspammer.com domain), any host in the entire
2350 top level domain TLD, 192.168.212.* network, and the IPv6 address
2351 2002:c0a8:51d2::23f4. It would allow relay for the IPv6 network
2352 2002:c0a8:02c7::/48.
2354 The value part of the map can contain:
2356 OK Accept mail even if other rules in the running
2357 ruleset would reject it, for example, if the domain
2358 name is unresolvable. "Accept" does not mean
2359 "relay", but at most acceptance for local
2360 recipients. That is, OK allows less than RELAY.
2361 RELAY Accept mail addressed to the indicated domain or
2362 received from the indicated domain for relaying
2363 through your SMTP server. RELAY also serves as
2364 an implicit OK for the other checks.
2365 REJECT Reject the sender or recipient with a general
2367 DISCARD Discard the message completely using the
2368 $#discard mailer. If it is used in check_compat,
2369 it affects only the designated recipient, not
2370 the whole message as it does in all other cases.
2371 This should only be used if really necessary.
2372 SKIP This can only be used for host/domain names
2373 and IP addresses/nets. It will abort the current
2374 search for this entry without accepting or rejecting
2375 it but causing the default action.
2376 ### any text where ### is an RFC 821 compliant error code and
2377 "any text" is a message to return for the command.
2378 The string should be quoted to avoid surprises,
2379 e.g., sendmail may remove spaces otherwise.
2380 This type is deprecated, use one the two
2381 ERROR: entries below instead.
2383 as above, but useful to mark error messages as such.
2384 ERROR:D.S.N:### any text
2385 where D.S.N is an RFC 1893 compliant error code
2386 and the rest as above.
2390 cyberspammer.com ERROR:"550 We don't accept mail from spammers"
2391 okay.cyberspammer.com OK
2394 IPv6:1:2:3:4:5:6:7 RELAY
2396 [IPv6:1:2:3:4:5:6:7:8] OK
2398 would accept mail from okay.cyberspammer.com, but would reject mail from
2399 all other hosts at cyberspammer.com with the indicated message. It would
2400 allow relaying mail from and to any hosts in the sendmail.org domain, and
2401 allow relaying from the 128.32.*.* network and the IPv6 1:2:3:4:5:6:7:*
2402 network. The latter two entries are for checks against ${client_name} if
2403 the IP address doesn't resolve to a hostname (or is considered as "may be
2404 forged"). That is, using square brackets means these are host names,
2405 not network numbers.
2407 Warning: if you change the RFC 821 compliant error code from the default
2408 value of 550, then you should probably also change the RFC 1893 compliant
2409 error code to match it. For example, if you use
2411 user@example.com ERROR:450 mailbox full
2413 the error returned would be "450 5.0.0 mailbox full" which is wrong.
2414 Use "ERROR:4.2.2:450 mailbox full" instead.
2416 Note, UUCP users may need to add hostname.UUCP to the access database
2421 FEATURE(`relay_hosts_only')
2423 then the above example will allow relaying for sendmail.org, but not
2424 hosts within the sendmail.org domain. Note that this will also require
2425 hosts listed in class {R} to be fully qualified host names.
2427 You can also use the access database to block sender addresses based on
2428 the username portion of the address. For example:
2430 FREE.STEALTH.MAILER@ ERROR:550 Spam not accepted
2432 Note that you must include the @ after the username to signify that
2433 this database entry is for checking only the username portion of the
2438 FEATURE(`blacklist_recipients')
2440 then you can add entries to the map for local users, hosts in your
2441 domains, or addresses in your domain which should not receive mail:
2443 badlocaluser@ ERROR:550 Mailbox disabled for this username
2444 host.mydomain.com ERROR:550 That host does not accept mail
2445 user@otherhost.mydomain.com ERROR:550 Mailbox disabled for this recipient
2447 This would prevent a recipient of badlocaluser@mydomain.com, any
2448 user at host.mydomain.com, and the single address
2449 user@otherhost.mydomain.com from receiving mail. Please note: a
2450 local username must be now tagged with an @ (this is consistent
2451 with the check of the sender address, and hence it is possible to
2452 distinguish between hostnames and usernames). Enabling this feature
2453 will keep you from sending mails to all addresses that have an
2454 error message or REJECT as value part in the access map. Taking
2455 the example from above:
2457 spammer@aol.com REJECT
2458 cyberspammer.com REJECT
2460 Mail can't be sent to spammer@aol.com or anyone at cyberspammer.com.
2462 There are several DNS based blacklists, the first of which was
2463 the RBL (``Realtime Blackhole List'') run by the MAPS project,
2464 see http://mail-abuse.org/. These are databases of spammers
2465 maintained in DNS. To use such a database, specify
2469 This will cause sendmail to reject mail from any site in the original
2470 Realtime Blackhole List database. This default DNS blacklist,
2471 blackholes.mail-abuse.org, is a service offered by the Mail Abuse
2472 Prevention System (MAPS). As of July 31, 2001, MAPS is a subscription
2473 service, so using that network address won't work if you haven't
2474 subscribed. Contact MAPS to subscribe (http://mail-abuse.org/).
2476 You can specify an alternative RBL server to check by specifying an
2477 argument to the FEATURE. The default error message is
2479 Rejected: IP-ADDRESS listed at SERVER
2481 where IP-ADDRESS and SERVER are replaced by the appropriate
2482 information. A second argument can be used to specify a different
2483 text. By default, temporary lookup failures are ignored and hence
2484 cause the connection not to be rejected by the DNS based rejection
2485 list. This behavior can be changed by specifying a third argument,
2486 which must be either `t' or a full error message. For example:
2488 FEATURE(`dnsbl', `dnsbl.example.com', `',
2489 `"451 Temporary lookup failure for " $&{client_addr} " in dnsbl.example.com"')
2491 If `t' is used, the error message is:
2493 451 Temporary lookup failure of IP-ADDRESS at SERVER
2495 where IP-ADDRESS and SERVER are replaced by the appropriate
2498 This FEATURE can be included several times to query different
2499 DNS based rejection lists, e.g., the dial-up user list (see
2500 http://mail-abuse.org/dul/).
2502 Notice: to avoid checking your own local domains against those
2503 blacklists, use the access_db feature and add:
2506 Connect:127.0.0.1 RELAY
2508 to the access map, where 10.1 is your local network. You may
2509 want to use "RELAY" instead of "OK" to allow also relaying
2510 instead of just disabling the DNS lookups in the backlists.
2513 The features described above make use of the check_relay, check_mail,
2514 and check_rcpt rulesets. Note that check_relay checks the SMTP
2515 client hostname and IP address when the connection is made to your
2516 server. It does not check if a mail message is being relayed to
2517 another server. That check is done in check_rcpt. If you wish to
2518 include your own checks, you can put your checks in the rulesets
2519 Local_check_relay, Local_check_mail, and Local_check_rcpt. For
2520 example if you wanted to block senders with all numeric usernames
2521 (i.e. 2312343@bigisp.com), you would use Local_check_mail and the
2525 Kallnumbers regex -a@MATCH ^[0-9]+$
2529 # check address against various regex checks
2530 R$* $: $>Parse0 $>3 $1
2531 R$+ < @ bigisp.com. > $* $: $(allnumbers $1 $)
2532 R@MATCH $#error $: 553 Header Error
2534 These rules are called with the original arguments of the corresponding
2535 check_* ruleset. If the local ruleset returns $#OK, no further checking
2536 is done by the features described above and the mail is accepted. If the
2537 local ruleset resolves to a mailer (such as $#error or $#discard), the
2538 appropriate action is taken. Otherwise, the results of the local
2539 rewriting are ignored.
2541 Finer control by using tags for the LHS of the access map
2542 ---------------------------------------------------------
2544 Read this section only if the options listed so far are not sufficient
2545 for your purposes. There is now the option to tag entries in the
2546 access map according to their type. Three tags are available:
2548 Connect: connection information (${client_addr}, ${client_name})
2549 From: envelope sender
2550 To: envelope recipient
2552 If the required item is looked up in a map, it will be tried first
2553 with the corresponding tag in front, then (as fallback to enable
2554 backward compatibility) without any tag, unless the specific feature
2555 requires a tag. For example,
2557 From:spammer@some.dom REJECT
2558 To:friend.domain RELAY
2559 Connect:friend.domain OK
2560 Connect:from.domain RELAY
2561 From:good@another.dom OK
2562 From:another.dom REJECT
2564 This would deny mails from spammer@some.dom but you could still
2565 send mail to that address even if FEATURE(`blacklist_recipients')
2566 is enabled. Your system will allow relaying to friend.domain, but
2567 not from it (unless enabled by other means). Connections from that
2568 domain will be allowed even if it ends up in one of the DNS based
2569 rejection lists. Relaying is enabled from from.domain but not to
2570 it (since relaying is based on the connection information for
2571 outgoing relaying, the tag Connect: must be used; for incoming
2572 relaying, which is based on the recipient address, To: must be
2573 used). The last two entries allow mails from good@another.dom but
2574 reject mail from all other addresses with another.dom as domain
2580 By using FEATURE(`delay_checks') the rulesets check_mail and check_relay
2581 will not be called when a client connects or issues a MAIL command,
2582 respectively. Instead, those rulesets will be called by the check_rcpt
2583 ruleset; they will be skipped if a sender has been authenticated using
2584 a "trusted" mechanism, i.e., one that is defined via TRUST_AUTH_MECH().
2585 If check_mail returns an error then the RCPT TO command will be rejected
2586 with that error. If it returns some other result starting with $# then
2587 check_relay will be skipped. If the sender address (or a part of it) is
2588 listed in the access map and it has a RHS of OK or RELAY, then check_relay
2589 will be skipped. This has an interesting side effect: if your domain is
2590 my.domain and you have
2594 in the access map, then all e-mail with a sender address of
2595 <user@my.domain> gets through, even if check_relay would reject it
2596 (e.g., based on the hostname or IP address). This allows spammers
2597 to get around DNS based blacklist by faking the sender address. To
2598 avoid this problem you have to use tagged entries:
2601 Connect:my.domain RELAY
2603 if you need those entries at all (class {R} may take care of them).
2605 FEATURE(`delay_checks') can take an optional argument:
2607 FEATURE(`delay_checks', `friend')
2608 enables spamfriend test
2609 FEATURE(`delay_checks', `hater')
2610 enables spamhater test
2612 If such an argument is given, the recipient will be looked up in the
2613 access map (using the tag Spam:). If the argument is `friend', then
2614 the default behavior is to apply the other rulesets and make a SPAM
2615 friend the exception. The rulesets check_mail and check_relay will be
2616 skipped only if the recipient address is found and has RHS FRIEND. If
2617 the argument is `hater', then the default behavior is to skip the rulesets
2618 check_mail and check_relay and make a SPAM hater the exception. The
2619 other two rulesets will be applied only if the recipient address is
2620 found and has RHS HATER.
2622 This allows for simple exceptions from the tests, e.g., by activating
2623 the friend option and having
2627 in the access map, mail to abuse@localdomain will get through (where
2628 "localdomain" is any domain in class {w}). It is also possible to
2629 specify a full address or an address with +detail:
2631 Spam:abuse@my.domain FRIEND
2632 Spam:me+abuse@ FRIEND
2633 Spam:spam.domain FRIEND
2635 Note: The required tag has been changed in 8.12 from To: to Spam:.
2636 This change is incompatible to previous versions. However, you can
2637 (for now) simply add the new entries to the access map, the old
2638 ones will be ignored. As soon as you removed the old entries from
2639 the access map, specify a third parameter (`n') to this feature and
2640 the backward compatibility rules will not be in the generated .cf
2646 You can also reject mail on the basis of the contents of headers.
2647 This is done by adding a ruleset call to the 'H' header definition command
2648 in sendmail.cf. For example, this can be used to check the validity of
2649 a Message-ID: header:
2652 HMessage-Id: $>CheckMessageId
2657 R$* $#error $: 553 Header Error
2659 The alternative format:
2661 HSubject: $>+CheckSubject
2663 that is, $>+ instead of $>, gives the full Subject: header including
2664 comments to the ruleset (comments in parentheses () are stripped
2667 A default ruleset for headers which don't have a specific ruleset
2668 defined for them can be given by:
2673 1. All rules act on tokens as explained in doc/op/op.{me,ps,txt}.
2674 That may cause problems with simple header checks due to the
2675 tokenization. It might be simpler to use a regex map and apply it
2677 2. There are no default rulesets coming with this distribution of
2678 sendmail. You can either write your own or you can search the
2679 WWW for examples, e.g., http://www.digitalanswers.org/check_local/
2681 After all of the headers are read, the check_eoh ruleset will be called for
2682 any final header-related checks. The ruleset is called with the number of
2683 headers and the size of all of the headers in bytes separated by $|. One
2684 example usage is to reject messages which do not have a Message-Id:
2685 header. However, the Message-Id: header is *NOT* a required header and is
2686 not a guaranteed spam indicator. This ruleset is an example and should
2687 probably not be used in production.
2691 HMessage-Id: $>CheckMessageId
2695 # Record the presence of the header
2696 R$* $: $(storage {MessageIdCheck} $@ OK $) $1
2698 R$* $#error $: 553 Header Error
2702 R$* $: < $&{MessageIdCheck} >
2703 # Clear the macro for the next message
2704 R$* $: $(storage {MessageIdCheck} $) $1
2705 # Has a Message-Id: header
2707 # Allow missing Message-Id: from local mail
2708 R$* $: < $&{client_name} >
2711 # Otherwise, reject the mail
2712 R$* $#error $: 553 Header Error
2718 In this text, cert will be used as an abreviation for X.509 certificate,
2719 DN (CN) is the distinguished (common) name of a cert, and CA is a
2720 certification authority, which signs (issues) certs.
2722 For STARTTLS to be offered by sendmail you need to set at least
2723 this variables (the file names and paths are just examples):
2725 define(`confCACERT_PATH', `/etc/mail/certs/')
2726 define(`confCACERT', `/etc/mail/certs/CA.cert.pem')
2727 define(`confSERVER_CERT', `/etc/mail/certs/my.cert.pem')
2728 define(`confSERVER_KEY', `/etc/mail/certs/my.key.pem')
2730 On systems which do not have the compile flag HASURANDOM set (see
2731 sendmail/README) you also must set confRAND_FILE.
2733 See doc/op/op.{me,ps,txt} for more information about these options,
2734 especially the sections ``Certificates for STARTTLS'' and ``PRNG for
2737 Macros related to STARTTLS are:
2739 ${cert_issuer} holds the DN of the CA (the cert issuer).
2740 ${cert_subject} holds the DN of the cert (called the cert subject).
2741 ${cn_issuer} holds the CN of the CA (the cert issuer).
2742 ${cn_subject} holds the CN of the cert (called the cert subject).
2743 ${tls_version} the TLS/SSL version used for the connection, e.g., TLSv1,
2744 TLSv1/SSLv3, SSLv3, SSLv2.
2745 ${cipher} the cipher used for the connection, e.g., EDH-DSS-DES-CBC3-SHA,
2746 EDH-RSA-DES-CBC-SHA, DES-CBC-MD5, DES-CBC3-SHA.
2747 ${cipher_bits} the keylength (in bits) of the symmetric encryption algorithm
2748 used for the connection.
2749 ${verify} holds the result of the verification of the presented cert.
2750 Possible values are:
2751 OK verification succeeded.
2752 NO no cert presented.
2753 NOT no cert requested.
2754 FAIL cert presented but could not be verified,
2755 e.g., the cert of the signing CA is missing.
2756 NONE STARTTLS has not been performed.
2757 TEMP temporary error occurred.
2758 PROTOCOL protocol error occurred (SMTP level).
2759 SOFTWARE STARTTLS handshake failed.
2760 ${server_name} the name of the server of the current outgoing SMTP
2762 ${server_addr} the address of the server of the current outgoing SMTP
2768 SMTP STARTTLS can allow relaying for remote SMTP clients which have
2769 successfully authenticated themselves. If the verification of the cert
2770 failed (${verify} != OK), relaying is subject to the usual rules.
2771 Otherwise the DN of the issuer is looked up in the access map using the
2772 tag CERTISSUER. If the resulting value is RELAY, relaying is allowed.
2773 If it is SUBJECT, the DN of the cert subject is looked up next in the
2774 access map using the tag CERTSUBJECT. If the value is RELAY, relaying
2777 ${cert_issuer} and ${cert_subject} can be optionally modified by regular
2778 expressions defined in the m4 variables _CERT_REGEX_ISSUER_ and
2779 _CERT_REGEX_SUBJECT_, respectively. To avoid problems with those macros in
2780 rulesets and map lookups, they are modified as follows: each non-printable
2781 character and the characters '<', '>', '(', ')', '"', '+', ' ' are replaced
2782 by their HEX value with a leading '+'. For example:
2784 /C=US/ST=California/O=endmail.org/OU=private/CN=Darth Mail (Cert)/Email=
2785 darth+cert@endmail.org
2789 /C=US/ST=California/O=endmail.org/OU=private/CN=
2790 Darth+20Mail+20+28Cert+29/Email=darth+2Bcert@endmail.org
2792 (line breaks have been inserted for readability).
2794 The macros which are subject to this encoding are ${cert_subject},
2795 ${cert_issuer}, ${cn_subject}, and ${cn_issuer}.
2799 To allow relaying for everyone who can present a cert signed by
2801 /C=US/ST=California/O=endmail.org/OU=private/CN=
2802 Darth+20Mail+20+28Cert+29/Email=darth+2Bcert@endmail.org
2806 CertIssuer:/C=US/ST=California/O=endmail.org/OU=private/CN=
2807 Darth+20Mail+20+28Cert+29/Email=darth+2Bcert@endmail.org RELAY
2809 To allow relaying only for a subset of machines that have a cert signed by
2811 /C=US/ST=California/O=endmail.org/OU=private/CN=
2812 Darth+20Mail+20+28Cert+29/Email=darth+2Bcert@endmail.org
2816 CertIssuer:/C=US/ST=California/O=endmail.org/OU=private/CN=
2817 Darth+20Mail+20+28Cert+29/Email=darth+2Bcert@endmail.org SUBJECT
2818 CertSubject:/C=US/ST=California/O=endmail.org/OU=private/CN=
2819 DeathStar/Email=deathstar@endmail.org RELAY
2821 Note: line breaks have been inserted after "CN=" for readability,
2822 each tagged entry must be one (long) line in the access map.
2824 Of course it is also possible to write a simple ruleset that allows
2825 relaying for everyone who can present a cert that can be verified, e.g.,
2832 Allowing Connections
2833 --------------------
2835 The rulesets tls_server, tls_client, and tls_rcpt are used to decide whether
2836 an SMTP connection is accepted (or should continue).
2838 tls_server is called when sendmail acts as client after a STARTTLS command
2839 (should) have been issued. The parameter is the value of ${verify}.
2841 tls_client is called when sendmail acts as server, after a STARTTLS command
2842 has been issued, and from check_mail. The parameter is the value of
2843 ${verify} and STARTTLS or MAIL, respectively.
2845 Both rulesets behave the same. If no access map is in use, the connection
2846 will be accepted unless ${verify} is SOFTWARE, in which case the connection
2847 is always aborted. For tls_server/tls_client, ${client_name}/${server_name}
2848 is looked up in the access map using the tag TLS_Srv/TLS_Clt, which is done
2849 with the ruleset LookUpDomain. If no entry is found, ${client_addr}
2850 (${server_addr}) is looked up in the access map (same tag, ruleset
2851 LookUpAddr). If this doesn't result in an entry either, just the tag is
2852 looked up in the access map (included the trailing colon). Notice:
2853 requiring that e-mail is sent to a server only encrypted, e.g., via
2855 TLS_Srv:secure.domain ENCR:112
2857 doesn't necessarily mean that e-mail sent to that domain is encrypted.
2858 If the domain has multiple MX servers, e.g.,
2860 secure.domain. IN MX 10 mail.secure.domain.
2861 secure.domain. IN MX 50 mail.other.domain.
2863 then mail to user@secure.domain may go unencrypted to mail.other.domain.
2864 tls_rcpt can be used to address this problem.
2866 tls_rcpt is called before a RCPT TO: command is sent. The parameter is the
2867 current recipient. This ruleset is only defined if FEATURE(`access_db')
2868 is selected. A recipient address user@domain is looked up in the access
2869 map in four formats: TLS_Rcpt:user@domain, TLS_Rcpt:user@, TLS_Rcpt:domain,
2870 and TLS_Rcpt:; the first match is taken.
2872 The result of the lookups is then used to call the ruleset TLS_connection,
2873 which checks the requirement specified by the RHS in the access map against
2874 the actual parameters of the current TLS connection, esp. ${verify} and
2875 ${cipher_bits}. Legal RHSs in the access map are:
2877 VERIFY verification must have succeeded
2878 VERIFY:bits verification must have succeeded and ${cipher_bits} must
2879 be greater than or equal bits.
2880 ENCR:bits ${cipher_bits} must be greater than or equal bits.
2882 The RHS can optionally be prefixed by TEMP+ or PERM+ to select a temporary
2883 or permanent error. The default is a temporary error code (403 4.7.0)
2884 unless the macro TLS_PERM_ERR is set during generation of the .cf file.
2886 If a certain level of encryption is required, then it might also be
2887 possible that this level is provided by the security layer from a SASL
2888 algorithm, e.g., DIGEST-MD5.
2890 Furthermore, there can be a list of extensions added. Such a list
2891 starts with '+' and the items are separated by '++'. Allowed
2894 CN:name name must match ${cn_subject}
2895 CN ${server_name} must match ${cn_subject}
2896 CS:name name must match ${cert_subject}
2897 CI:name name must match ${cert_issuer}
2899 Example: e-mail sent to secure.example.com should only use an encrypted
2900 connection. E-mail received from hosts within the laptop.example.com domain
2901 should only be accepted if they have been authenticated. The host which
2902 receives e-mail for darth@endmail.org must present a cert that uses the
2903 CN smtp.endmail.org.
2905 TLS_Srv:secure.example.com ENCR:112
2906 TLS_Clt:laptop.example.com PERM+VERIFY:112
2907 TLS_Rcpt:darth@endmail.org ENCR:112+CN:smtp.endmail.org
2910 Disabling STARTTLS And Setting SMTP Server Features
2911 ---------------------------------------------------
2913 By default STARTTLS is used whenever possible. However, there are
2914 some broken MTAs that don't properly implement STARTTLS. To be able
2915 to send to (or receive from) those MTAs, the ruleset try_tls
2916 (srv_features) can be used that work together with the access map.
2917 Entries for the access map must be tagged with Try_TLS (Srv_Features)
2918 and refer to the hostname or IP address of the connecting system.
2919 A default case can be specified by using just the tag. For example,
2920 the following entries in the access map:
2922 Try_TLS:broken.server NO
2923 Srv_Features:my.domain v
2926 will turn off STARTTLS when sending to broken.server (or any host
2927 in that domain), and request a client certificate during the TLS
2928 handshake only for hosts in my.domain. The valid entries on the RHS
2929 for Srv_Features are listed in the Sendmail Installation and
2936 The Received: header reveals whether STARTTLS has been used. It contains an
2939 (version=${tls_version} cipher=${cipher} bits=${cipher_bits} verify=${verify})
2942 +---------------------+
2943 | SMTP AUTHENTICATION |
2944 +---------------------+
2946 The macros ${auth_authen}, ${auth_author}, and ${auth_type} can be
2947 used in anti-relay rulesets to allow relaying for those users that
2948 authenticated themselves. A very simple example is:
2951 R$* $: $&{auth_type}
2954 which checks whether a user has successfully authenticated using
2955 any available mechanism. Depending on the setup of the CYRUS SASL
2956 library, more sophisticated rulesets might be required, e.g.,
2959 R$* $: $&{auth_type} $| $&{auth_authen}
2960 RDIGEST-MD5 $| $+@$=w $# OK
2962 to allow relaying for users that authenticated using DIGEST-MD5
2963 and have an identity in the local domains.
2965 The ruleset trust_auth is used to determine whether a given AUTH=
2966 parameter (that is passed to this ruleset) should be trusted. This
2967 ruleset may make use of the other ${auth_*} macros. Only if the
2968 ruleset resolves to the error mailer, the AUTH= parameter is not
2969 trusted. A user supplied ruleset Local_trust_auth can be written
2970 to modify the default behavior, which only trust the AUTH=
2971 parameter if it is identical to the authenticated user.
2973 Per default, relaying is allowed for any user who authenticated
2974 via a "trusted" mechanism, i.e., one that is defined via
2975 TRUST_AUTH_MECH(`list of mechanisms')
2977 TRUST_AUTH_MECH(`KERBEROS_V4 DIGEST-MD5')
2979 If the selected mechanism provides a security layer the number of
2980 bits used for the key of the symmetric cipher is stored in the
2983 If sendmail acts as client, it needs some information how to
2984 authenticate against another MTA. This information can be provided
2985 by the ruleset authinfo or by the option DefaultAuthInfo. The
2986 authinfo ruleset looks up {server_name} using the tag AuthInfo: in
2987 the access map. If no entry is found, {server_addr} is looked up
2988 in the same way and finally just the tag AuthInfo: to provide
2989 default values. Note: searches for domain parts or IP nets are
2990 only performed if the access map is used; if the authinfo feature
2991 is used then only up to three lookups are performed (two exact
2992 matches, one default).
2994 Notice: the default configuration file causes the option DefaultAuthInfo
2995 to fail since the ruleset authinfo is in the .cf file. If you really
2996 want to use DefaultAuthInfo (it is deprecated) then you have to
2999 The RHS for an AuthInfo: entry in the access map should consists of a
3000 list of tokens, each of which has the form: "TDstring" (including
3001 the quotes). T is a tag which describes the item, D is a delimiter,
3002 either ':' for simple text or '=' for a base64 encoded string.
3003 Valid values for the tag are:
3005 U user (authorization) id
3009 M list of mechanisms delimited by spaces
3011 Example entries are:
3013 AuthInfo:other.dom "U:user" "I:user" "P:secret" "R:other.dom" "M:DIGEST-MD5"
3014 AuthInfo:host.more.dom "U:user" "P=c2VjcmV0"
3016 User id or authentication id must exist as well as the password. All
3017 other entries have default values. If one of user or authentication
3018 id is missing, the existing value is used for the missing item.
3019 If "R:" is not specified, realm defaults to $j. The list of mechanisms
3020 defaults to those specified by AuthMechanisms.
3022 Since this map contains sensitive information, either the access
3023 map must be unreadable by everyone but root (or the trusted user)
3024 or FEATURE(`authinfo') must be used which provides a separate map.
3025 Notice: It is not checked whether the map is actually
3026 group/world-unreadable, this is left to the user.
3028 +--------------------------------+
3029 | ADDING NEW MAILERS OR RULESETS |
3030 +--------------------------------+
3032 Sometimes you may need to add entirely new mailers or rulesets. They
3033 should be introduced with the constructs MAILER_DEFINITIONS and
3034 LOCAL_RULESETS respectively. For example:
3044 Local additions for the rulesets srv_features, try_tls, tls_rcpt,
3045 tls_client, and tls_server can be made using LOCAL_SRV_FEATURES,
3046 LOCAL_TRY_TLS, LOCAL_TLS_RCPT, LOCAL_TLS_CLIENT, and LOCAL_TLS_SERVER,
3047 respectively. For example, to add a local ruleset that decides
3048 whether to try STARTTLS in a sendmail client, use:
3053 Note: you don't need to add a name for the ruleset, it is implicitly
3054 defined by using the appropriate macro.
3057 +-------------------------+
3058 | ADDING NEW MAIL FILTERS |
3059 +-------------------------+
3061 Sendmail supports mail filters to filter incoming SMTP messages according
3062 to the "Sendmail Mail Filter API" documentation. These filters can be
3063 configured in your mc file using the two commands:
3065 MAIL_FILTER(`name', `equates')
3066 INPUT_MAIL_FILTER(`name', `equates')
3068 The first command, MAIL_FILTER(), simply defines a filter with the given
3069 name and equates. For example:
3071 MAIL_FILTER(`archive', `S=local:/var/run/archivesock, F=R')
3073 This creates the equivalent sendmail.cf entry:
3075 Xarchive, S=local:/var/run/archivesock, F=R
3077 The INPUT_MAIL_FILTER() command performs the same actions as MAIL_FILTER
3078 but also populates the m4 variable `confINPUT_MAIL_FILTERS' with the name
3079 of the filter such that the filter will actually be called by sendmail.
3081 For example, the two commands:
3083 INPUT_MAIL_FILTER(`archive', `S=local:/var/run/archivesock, F=R')
3084 INPUT_MAIL_FILTER(`spamcheck', `S=inet:2525@localhost, F=T')
3086 are equivalent to the three commands:
3088 MAIL_FILTER(`archive', `S=local:/var/run/archivesock, F=R')
3089 MAIL_FILTER(`spamcheck', `S=inet:2525@localhost, F=T')
3090 define(`confINPUT_MAIL_FILTERS', `archive, spamcheck')
3092 In general, INPUT_MAIL_FILTER() should be used unless you need to define
3093 more filters than you want to use for `confINPUT_MAIL_FILTERS'.
3095 Note that setting `confINPUT_MAIL_FILTERS' after any INPUT_MAIL_FILTER()
3096 commands will clear the list created by the prior INPUT_MAIL_FILTER()
3100 +-------------------------+
3101 | QUEUE GROUP DEFINITIONS |
3102 +-------------------------+
3104 In addition to the queue directory (which is the default queue group
3105 called "mqueue"), sendmail can deal with multiple queue groups, which
3106 are collections of queue directories with the same behaviour. Queue
3107 groups can be defined using the command:
3109 QUEUE_GROUP(`name', `equates')
3111 For details about queue groups, please see doc/op/op.{me,ps,txt}.
3113 +-------------------------------+
3114 | NON-SMTP BASED CONFIGURATIONS |
3115 +-------------------------------+
3117 These configuration files are designed primarily for use by
3118 SMTP-based sites. They may not be well tuned for UUCP-only or
3119 UUCP-primarily nodes (the latter is defined as a small local net
3120 connected to the rest of the world via UUCP). However, there is
3121 one hook to handle some special cases.
3123 You can define a ``smart host'' that understands a richer address syntax
3126 define(`SMART_HOST', `mailer:hostname')
3128 In this case, the ``mailer:'' defaults to "relay". Any messages that
3129 can't be handled using the usual UUCP rules are passed to this host.
3131 If you are on a local SMTP-based net that connects to the outside
3132 world via UUCP, you can use LOCAL_NET_CONFIG to add appropriate rules.
3135 define(`SMART_HOST', `uucp-new:uunet')
3137 R$* < @ $* .$m. > $* $#smtp $@ $2.$m. $: $1 < @ $2.$m. > $3
3139 This will cause all names that end in your domain name ($m) to be sent
3140 via SMTP; anything else will be sent via uucp-new (smart UUCP) to uunet.
3141 If you have FEATURE(`nocanonify'), you may need to omit the dots after
3142 the $m. If you are running a local DNS inside your domain which is
3143 not otherwise connected to the outside world, you probably want to
3146 define(`SMART_HOST', `smtp:fire.wall.com')
3148 R$* < @ $* . > $* $#smtp $@ $2. $: $1 < @ $2. > $3
3150 That is, send directly only to things you found in your DNS lookup;
3151 anything else goes through SMART_HOST.
3153 You may need to turn off the anti-spam rules in order to accept
3154 UUCP mail with FEATURE(`promiscuous_relay') and
3155 FEATURE(`accept_unresolvable_domains').
3162 Normally, the $j macro is automatically defined to be your fully
3163 qualified domain name (FQDN). Sendmail does this by getting your
3164 host name using gethostname and then calling gethostbyname on the
3165 result. For example, in some environments gethostname returns
3166 only the root of the host name (such as "foo"); gethostbyname is
3167 supposed to return the FQDN ("foo.bar.com"). In some (fairly rare)
3168 cases, gethostbyname may fail to return the FQDN. In this case
3169 you MUST define confDOMAIN_NAME to be your fully qualified domain
3170 name. This is usually done using:
3173 define(`confDOMAIN_NAME', `$w.$m')dnl
3176 +-----------------------------------+
3177 | ACCEPTING MAIL FOR MULTIPLE NAMES |
3178 +-----------------------------------+
3180 If your host is known by several different names, you need to augment
3181 class {w}. This is a list of names by which your host is known, and
3182 anything sent to an address using a host name in this list will be
3183 treated as local mail. You can do this in two ways: either create the
3184 file /etc/mail/local-host-names containing a list of your aliases (one per
3185 line), and use ``FEATURE(`use_cw_file')'' in the .mc file, or add
3186 ``LOCAL_DOMAIN(`alias.host.name')''. Be sure you use the fully-qualified
3187 name of the host, rather than a short name.
3189 If you want to have different address in different domains, take
3190 a look at the virtusertable feature, which is also explained at
3191 http://www.sendmail.org/virtual-hosting.html
3194 +--------------------+
3195 | USING MAILERTABLES |
3196 +--------------------+
3198 To use FEATURE(`mailertable'), you will have to create an external
3199 database containing the routing information for various domains.
3200 For example, a mailertable file in text format might be:
3202 .my.domain xnet:%1.my.domain
3203 uuhost1.my.domain uucp-new:uuhost1
3204 .bitnet smtp:relay.bit.net
3206 This should normally be stored in /etc/mail/mailertable. The actual
3207 database version of the mailertable is built using:
3209 makemap hash /etc/mail/mailertable < /etc/mail/mailertable
3211 The semantics are simple. Any LHS entry that does not begin with
3212 a dot matches the full host name indicated. LHS entries beginning
3213 with a dot match anything ending with that domain name (including
3214 the leading dot) -- that is, they can be thought of as having a
3215 leading ".+" regular expression pattern for a non-empty sequence of
3216 characters. Matching is done in order of most-to-least qualified
3217 -- for example, even though ".my.domain" is listed first in the
3218 above example, an entry of "uuhost1.my.domain" will match the second
3219 entry since it is more explicit. Note: e-mail to "user@my.domain"
3220 does not match any entry in the above table. You need to have
3223 my.domain esmtp:host.my.domain
3225 The RHS should always be a "mailer:host" pair. The mailer is the
3226 configuration name of a mailer (that is, an M line in the
3227 sendmail.cf file). The "host" will be the hostname passed to
3228 that mailer. In domain-based matches (that is, those with leading
3229 dots) the "%1" may be used to interpolate the wildcarded part of
3230 the host name. For example, the first line above sends everything
3231 addressed to "anything.my.domain" to that same host name, but using
3232 the (presumably experimental) xnet mailer.
3234 In some cases you may want to temporarily turn off MX records,
3235 particularly on gateways. For example, you may want to MX
3236 everything in a domain to one machine that then forwards it
3237 directly. To do this, you might use the DNS configuration:
3239 *.domain. IN MX 0 relay.machine
3241 and on relay.machine use the mailertable:
3243 .domain smtp:[gateway.domain]
3245 The [square brackets] turn off MX records for this host only.
3246 If you didn't do this, the mailertable would use the MX record
3247 again, which would give you an MX loop. Note that the use of
3248 wildcard MX records is almost always a bad idea. Please avoid
3249 using them if possible.
3252 +--------------------------------+
3253 | USING USERDB TO MAP FULL NAMES |
3254 +--------------------------------+
3256 The user database was not originally intended for mapping full names
3257 to login names (e.g., Eric.Allman => eric), but some people are using
3258 it that way. (it is recommended that you set up aliases for this
3259 purpose instead -- since you can specify multiple alias files, this
3260 is fairly easy.) The intent was to locate the default maildrop at
3261 a site, but allow you to override this by sending to a specific host.
3263 If you decide to set up the user database in this fashion, it is
3264 imperative that you not use FEATURE(`stickyhost') -- otherwise,
3265 e-mail sent to Full.Name@local.host.name will be rejected.
3267 To build the internal form of the user database, use:
3269 makemap btree /etc/mail/userdb < /etc/mail/userdb.txt
3271 As a general rule, it is an extremely bad idea to using full names
3272 as e-mail addresses, since they are not in any sense unique. For
3273 example, the UNIX software-development community has at least two
3274 well-known Peter Deutsches, and at one time Bell Labs had two
3275 Stephen R. Bournes with offices along the same hallway. Which one
3276 will be forced to suffer the indignity of being Stephen_R_Bourne_2?
3277 The less famous of the two, or the one that was hired later?
3279 Finger should handle full names (and be fuzzy). Mail should use
3280 handles, and not be fuzzy.
3283 +--------------------------------+
3284 | MISCELLANEOUS SPECIAL FEATURES |
3285 +--------------------------------+
3288 Sometimes it is convenient to merge configuration on a
3289 centralized mail machine, for example, to forward all
3290 root mail to a mail server. In this case it might be
3291 useful to be able to treat the root addresses as a class
3292 of addresses with subtle differences. You can do this
3293 using plussed users. For example, a client might include
3296 root: root+client1@server
3298 On the server, this will match an alias for "root+client1".
3299 If that is not found, the alias "root+*" will be tried,
3307 A lot of sendmail security comes down to you. Sendmail 8 is much
3308 more careful about checking for security problems than previous
3309 versions, but there are some things that you still need to watch
3312 * Make sure the aliases file is not writable except by trusted
3313 system personnel. This includes both the text and database
3316 * Make sure that other files that sendmail reads, such as the
3317 mailertable, are only writable by trusted system personnel.
3319 * The queue directory should not be world writable PARTICULARLY
3320 if your system allows "file giveaways" (that is, if a non-root
3321 user can chown any file they own to any other user).
3323 * If your system allows file giveaways, DO NOT create a publically
3324 writable directory for forward files. This will allow anyone
3325 to steal anyone else's e-mail. Instead, create a script that
3326 copies the .forward file from users' home directories once a
3327 night (if you want the non-NFS-mounted forward directory).
3329 * If your system allows file giveaways, you'll find that
3330 sendmail is much less trusting of :include: files -- in
3331 particular, you'll have to have /SENDMAIL/ANY/SHELL/ in
3332 /etc/shells before they will be trusted (that is, before
3333 files and programs listed in them will be honored).
3335 In general, file giveaways are a mistake -- if you can turn them
3339 +--------------------------------+
3340 | TWEAKING CONFIGURATION OPTIONS |
3341 +--------------------------------+
3343 There are a large number of configuration options that don't normally
3344 need to be changed. However, if you feel you need to tweak them, you
3345 can define the following M4 variables. This list is shown in four
3346 columns: the name you define, the default value for that definition,
3347 the option or macro that is affected (either Ox for an option or Dx
3348 for a macro), and a brief description. Greater detail of the semantics
3349 can be found in the Installation and Operations Guide.
3351 Some options are likely to be deprecated in future versions -- that is,
3352 the option is only included to provide back-compatibility. These are
3355 Remember that these options are M4 variables, and hence may need to
3356 be quoted. In particular, arguments with commas will usually have to
3357 be ``double quoted, like this phrase'' to avoid having the comma
3358 confuse things. This is common for alias file definitions and for
3361 M4 Variable Name Configuration Description & [Default]
3362 ================ ============= =======================
3363 confMAILER_NAME $n macro [MAILER-DAEMON] The sender name used
3364 for internally generated outgoing
3366 confDOMAIN_NAME $j macro If defined, sets $j. This should
3367 only be done if your system cannot
3368 determine your local domain name,
3369 and then it should be set to
3370 $w.Foo.COM, where Foo.COM is your
3372 confCF_VERSION $Z macro If defined, this is appended to the
3373 configuration version name.
3374 confLDAP_CLUSTER ${sendmailMTACluster} macro
3375 If defined, this is the LDAP
3376 cluster to use for LDAP searches
3377 as described above in ``USING LDAP
3378 FOR ALIASES, MAPS, AND CLASSES''.
3379 confFROM_HEADER From: [$?x$x <$g>$|$g$.] The format of an
3380 internally generated From: address.
3381 confRECEIVED_HEADER Received:
3382 [$?sfrom $s $.$?_($?s$|from $.$_)
3383 $.$?{auth_type}(authenticated)
3384 $.by $j ($v/$Z)$?r with $r$. id $i$?u
3387 The format of the Received: header
3388 in messages passed through this host.
3389 It is unwise to try to change this.
3390 confCW_FILE Fw class [/etc/mail/local-host-names] Name
3391 of file used to get the local
3392 additions to class {w} (local host
3394 confCT_FILE Ft class [/etc/mail/trusted-users] Name of
3395 file used to get the local additions
3396 to class {t} (trusted users).
3397 confCR_FILE FR class [/etc/mail/relay-domains] Name of
3398 file used to get the local additions
3399 to class {R} (hosts allowed to relay).
3400 confTRUSTED_USERS Ct class [no default] Names of users to add to
3401 the list of trusted users. This list
3402 always includes root, uucp, and daemon.
3403 See also FEATURE(`use_ct_file').
3404 confTRUSTED_USER TrustedUser [no default] Trusted user for file
3405 ownership and starting the daemon.
3406 Not to be confused with
3407 confTRUSTED_USERS (see above).
3408 confSMTP_MAILER - [esmtp] The mailer name used when
3409 SMTP connectivity is required.
3410 One of "smtp", "smtp8",
3411 "esmtp", or "dsmtp".
3412 confUUCP_MAILER - [uucp-old] The mailer to be used by
3413 default for bang-format recipient
3414 addresses. See also discussion of
3415 class {U}, class {Y}, and class {Z}
3416 in the MAILER(`uucp') section.
3417 confLOCAL_MAILER - [local] The mailer name used when
3418 local connectivity is required.
3419 Almost always "local".
3420 confRELAY_MAILER - [relay] The default mailer name used
3421 for relaying any mail (e.g., to a
3422 BITNET_RELAY, a SMART_HOST, or
3423 whatever). This can reasonably be
3424 "uucp-new" if you are on a
3425 UUCP-connected site.
3426 confSEVEN_BIT_INPUT SevenBitInput [False] Force input to seven bits?
3427 confEIGHT_BIT_HANDLING EightBitMode [pass8] 8-bit data handling
3428 confALIAS_WAIT AliasWait [10m] Time to wait for alias file
3429 rebuild until you get bored and
3430 decide that the apparently pending
3432 confMIN_FREE_BLOCKS MinFreeBlocks [100] Minimum number of free blocks on
3433 queue filesystem to accept SMTP mail.
3434 (Prior to 8.7 this was minfree/maxsize,
3435 where minfree was the number of free
3436 blocks and maxsize was the maximum
3437 message size. Use confMAX_MESSAGE_SIZE
3438 for the second value now.)
3439 confMAX_MESSAGE_SIZE MaxMessageSize [infinite] The maximum size of messages
3440 that will be accepted (in bytes).
3441 confBLANK_SUB BlankSub [.] Blank (space) substitution
3443 confCON_EXPENSIVE HoldExpensive [False] Avoid connecting immediately
3444 to mailers marked expensive.
3445 confCHECKPOINT_INTERVAL CheckpointInterval
3446 [10] Checkpoint queue files every N
3448 confDELIVERY_MODE DeliveryMode [background] Default delivery mode.
3449 confERROR_MODE ErrorMode [print] Error message mode.
3450 confERROR_MESSAGE ErrorHeader [undefined] Error message header/file.
3451 confSAVE_FROM_LINES SaveFromLine Save extra leading From_ lines.
3452 confTEMP_FILE_MODE TempFileMode [0600] Temporary file mode.
3453 confMATCH_GECOS MatchGECOS [False] Match GECOS field.
3454 confMAX_HOP MaxHopCount [25] Maximum hop count.
3455 confIGNORE_DOTS* IgnoreDots [False; always False in -bs or -bd
3456 mode] Ignore dot as terminator for
3458 confBIND_OPTS ResolverOptions [undefined] Default options for DNS
3460 confMIME_FORMAT_ERRORS* SendMimeErrors [True] Send error messages as MIME-
3461 encapsulated messages per RFC 1344.
3462 confFORWARD_PATH ForwardPath [$z/.forward.$w:$z/.forward]
3463 The colon-separated list of places to
3464 search for .forward files. N.B.: see
3465 the Security Notes section.
3466 confMCI_CACHE_SIZE ConnectionCacheSize
3467 [2] Size of open connection cache.
3468 confMCI_CACHE_TIMEOUT ConnectionCacheTimeout
3469 [5m] Open connection cache timeout.
3470 confHOST_STATUS_DIRECTORY HostStatusDirectory
3471 [undefined] If set, host status is kept
3472 on disk between sendmail runs in the
3473 named directory tree. This need not be
3474 a full pathname, in which case it is
3475 interpreted relative to the queue
3477 confSINGLE_THREAD_DELIVERY SingleThreadDelivery
3478 [False] If this option and the
3479 HostStatusDirectory option are both
3480 set, single thread deliveries to other
3481 hosts. That is, don't allow any two
3482 sendmails on this host to connect
3483 simultaneously to any other single
3484 host. This can slow down delivery in
3485 some cases, in particular since a
3486 cached but otherwise idle connection
3487 to a host will prevent other sendmails
3488 from connecting to the other host.
3489 confUSE_ERRORS_TO* UseErrorsTo [False] Use the Errors-To: header to
3490 deliver error messages. This should
3491 not be necessary because of general
3492 acceptance of the envelope/header
3494 confLOG_LEVEL LogLevel [9] Log level.
3495 confME_TOO MeToo [True] Include sender in group
3496 expansions. This option is
3497 deprecated and will be removed from
3499 confCHECK_ALIASES CheckAliases [False] Check RHS of aliases when
3500 running newaliases. Since this does
3501 DNS lookups on every address, it can
3502 slow down the alias rebuild process
3503 considerably on large alias files.
3504 confOLD_STYLE_HEADERS* OldStyleHeaders [True] Assume that headers without
3505 special chars are old style.
3506 confPRIVACY_FLAGS PrivacyOptions [authwarnings] Privacy flags.
3507 confCOPY_ERRORS_TO PostmasterCopy [undefined] Address for additional
3508 copies of all error messages.
3509 confQUEUE_FACTOR QueueFactor [600000] Slope of queue-only function.
3510 confQUEUE_FILE_MODE QueueFileMode [undefined] Default permissions for
3511 queue files (octal). If not set,
3512 sendmail uses 0600 unless its real
3513 and effective uid are different in
3514 which case it uses 0644.
3515 confDONT_PRUNE_ROUTES DontPruneRoutes [False] Don't prune down route-addr
3516 syntax addresses to the minimum
3518 confSAFE_QUEUE* SuperSafe [True] Commit all messages to disk
3520 confTO_INITIAL Timeout.initial [5m] The timeout waiting for a response
3521 on the initial connect.
3522 confTO_CONNECT Timeout.connect [0] The timeout waiting for an initial
3523 connect() to complete. This can only
3524 shorten connection timeouts; the kernel
3525 silently enforces an absolute maximum
3526 (which varies depending on the system).
3527 confTO_ICONNECT Timeout.iconnect
3528 [undefined] Like Timeout.connect, but
3529 applies only to the very first attempt
3530 to connect to a host in a message.
3531 This allows a single very fast pass
3532 followed by more careful delivery
3533 attempts in the future.
3534 confTO_ACONNECT Timeout.aconnect
3535 [0] The overall timeout waiting for
3536 all connection for a single delivery
3537 attempt to succeed. If 0, no overall
3539 confTO_HELO Timeout.helo [5m] The timeout waiting for a response
3540 to a HELO or EHLO command.
3541 confTO_MAIL Timeout.mail [10m] The timeout waiting for a
3542 response to the MAIL command.
3543 confTO_RCPT Timeout.rcpt [1h] The timeout waiting for a response
3544 to the RCPT command.
3545 confTO_DATAINIT Timeout.datainit
3546 [5m] The timeout waiting for a 354
3547 response from the DATA command.
3548 confTO_DATABLOCK Timeout.datablock
3549 [1h] The timeout waiting for a block
3551 confTO_DATAFINAL Timeout.datafinal
3552 [1h] The timeout waiting for a response
3553 to the final "." that terminates a
3555 confTO_RSET Timeout.rset [5m] The timeout waiting for a response
3556 to the RSET command.
3557 confTO_QUIT Timeout.quit [2m] The timeout waiting for a response
3558 to the QUIT command.
3559 confTO_MISC Timeout.misc [2m] The timeout waiting for a response
3560 to other SMTP commands.
3561 confTO_COMMAND Timeout.command [1h] In server SMTP, the timeout
3562 waiting for a command to be issued.
3563 confTO_IDENT Timeout.ident [5s] The timeout waiting for a
3564 response to an IDENT query.
3565 confTO_FILEOPEN Timeout.fileopen
3566 [60s] The timeout waiting for a file
3567 (e.g., :include: file) to be opened.
3568 confTO_LHLO Timeout.lhlo [2m] The timeout waiting for a response
3569 to an LMTP LHLO command.
3570 confTO_AUTH Timeout.auth [10m] The timeout waiting for a
3571 response in an AUTH dialogue.
3572 confTO_STARTTLS Timeout.starttls
3573 [1h] The timeout waiting for a
3574 response to an SMTP STARTTLS command.
3575 confTO_CONTROL Timeout.control
3576 [2m] The timeout for a complete
3577 control socket transaction to complete.
3578 confTO_QUEUERETURN Timeout.queuereturn
3579 [5d] The timeout before a message is
3580 returned as undeliverable.
3581 confTO_QUEUERETURN_NORMAL
3582 Timeout.queuereturn.normal
3583 [undefined] As above, for normal
3585 confTO_QUEUERETURN_URGENT
3586 Timeout.queuereturn.urgent
3587 [undefined] As above, for urgent
3589 confTO_QUEUERETURN_NONURGENT
3590 Timeout.queuereturn.non-urgent
3591 [undefined] As above, for non-urgent
3592 (low) priority messages.
3593 confTO_QUEUEWARN Timeout.queuewarn
3594 [4h] The timeout before a warning
3595 message is sent to the sender telling
3596 them that the message has been
3598 confTO_QUEUEWARN_NORMAL Timeout.queuewarn.normal
3599 [undefined] As above, for normal
3601 confTO_QUEUEWARN_URGENT Timeout.queuewarn.urgent
3602 [undefined] As above, for urgent
3604 confTO_QUEUEWARN_NONURGENT
3605 Timeout.queuewarn.non-urgent
3606 [undefined] As above, for non-urgent
3607 (low) priority messages.
3608 confTO_HOSTSTATUS Timeout.hoststatus
3609 [30m] How long information about host
3610 statuses will be maintained before it
3611 is considered stale and the host should
3612 be retried. This applies both within
3613 a single queue run and to persistent
3614 information (see below).
3615 confTO_RESOLVER_RETRANS Timeout.resolver.retrans
3616 [varies] Sets the resolver's
3617 retransmission time interval (in
3619 Timeout.resolver.retrans.first and
3620 Timeout.resolver.retrans.normal.
3621 confTO_RESOLVER_RETRANS_FIRST Timeout.resolver.retrans.first
3622 [varies] Sets the resolver's
3623 retransmission time interval (in
3624 seconds) for the first attempt to
3626 confTO_RESOLVER_RETRANS_NORMAL Timeout.resolver.retrans.normal
3627 [varies] Sets the resolver's
3628 retransmission time interval (in
3629 seconds) for all resolver lookups
3630 except the first delivery attempt.
3631 confTO_RESOLVER_RETRY Timeout.resolver.retry
3632 [varies] Sets the number of times
3633 to retransmit a resolver query.
3635 Timeout.resolver.retry.first and
3636 Timeout.resolver.retry.normal.
3637 confTO_RESOLVER_RETRY_FIRST Timeout.resolver.retry.first
3638 [varies] Sets the number of times
3639 to retransmit a resolver query for
3640 the first attempt to deliver a
3642 confTO_RESOLVER_RETRY_NORMAL Timeout.resolver.retry.normal
3643 [varies] Sets the number of times
3644 to retransmit a resolver query for
3645 all resolver lookups except the
3646 first delivery attempt.
3647 confTIME_ZONE TimeZoneSpec [USE_SYSTEM] Time zone info -- can be
3648 USE_SYSTEM to use the system's idea,
3649 USE_TZ to use the user's TZ envariable,
3650 or something else to force that value.
3651 confDEF_USER_ID DefaultUser [1:1] Default user id.
3652 confUSERDB_SPEC UserDatabaseSpec
3653 [undefined] User database
3655 confFALLBACK_MX FallbackMXhost [undefined] Fallback MX host.
3656 confTRY_NULL_MX_LIST TryNullMXList [False] If this host is the best MX
3657 for a host and other arrangements
3658 haven't been made, try connecting
3659 to the host directly; normally this
3660 would be a config error.
3661 confQUEUE_LA QueueLA [varies] Load average at which
3662 queue-only function kicks in.
3663 Default values is (8 * numproc)
3664 where numproc is the number of
3665 processors online (if that can be
3667 confREFUSE_LA RefuseLA [varies] Load average at which
3668 incoming SMTP connections are
3669 refused. Default values is (12 *
3670 numproc) where numproc is the
3671 number of processors online (if
3672 that can be determined).
3673 confDELAY_LA DelayLA [0] Load average at which sendmail
3674 will sleep for one second on most
3675 SMTP commands and before accepting
3676 connections. 0 means no limit.
3677 confMAX_ALIAS_RECURSION MaxAliasRecursion
3678 [10] Maximum depth of alias recursion.
3679 confMAX_DAEMON_CHILDREN MaxDaemonChildren
3680 [undefined] The maximum number of
3681 children the daemon will permit. After
3682 this number, connections will be
3683 rejected. If not set or <= 0, there is
3685 confMAX_HEADERS_LENGTH MaxHeadersLength
3686 [32768] Maximum length of the sum
3688 confMAX_MIME_HEADER_LENGTH MaxMimeHeaderLength
3689 [undefined] Maximum length of
3690 certain MIME header field values.
3691 If not set, sendmail uses 2048/1024.
3692 confCONNECTION_RATE_THROTTLE ConnectionRateThrottle
3693 [undefined] The maximum number of
3694 connections permitted per second per
3695 daemon. After this many connections
3696 are accepted, further connections
3697 will be delayed. If not set or <= 0,
3699 confWORK_RECIPIENT_FACTOR
3700 RecipientFactor [30000] Cost of each recipient.
3701 confSEPARATE_PROC ForkEachJob [False] Run all deliveries in a
3703 confWORK_CLASS_FACTOR ClassFactor [1800] Priority multiplier for class.
3704 confWORK_TIME_FACTOR RetryFactor [90000] Cost of each delivery attempt.
3705 confQUEUE_SORT_ORDER QueueSortOrder [Priority] Queue sort algorithm:
3706 Priority, Host, Filename, Random,
3707 Modification, or Time.
3708 confMIN_QUEUE_AGE MinQueueAge [0] The minimum amount of time a job
3709 must sit in the queue between queue
3710 runs. This allows you to set the
3711 queue run interval low for better
3712 responsiveness without trying all
3714 confDEF_CHAR_SET DefaultCharSet [unknown-8bit] When converting
3715 unlabeled 8 bit input to MIME, the
3716 character set to use by default.
3717 confSERVICE_SWITCH_FILE ServiceSwitchFile
3718 [/etc/mail/service.switch] The file
3719 to use for the service switch on
3720 systems that do not have a
3721 system-defined switch.
3722 confHOSTS_FILE HostsFile [/etc/hosts] The file to use when doing
3723 "file" type access of hosts names.
3724 confDIAL_DELAY DialDelay [0s] If a connection fails, wait this
3725 long and try again. Zero means "don't
3726 retry". This is to allow "dial on
3727 demand" connections to have enough time
3728 to complete a connection.
3729 confNO_RCPT_ACTION NoRecipientAction
3730 [none] What to do if there are no legal
3731 recipient fields (To:, Cc: or Bcc:)
3732 in the message. Legal values can
3733 be "none" to just leave the
3734 nonconforming message as is, "add-to"
3735 to add a To: header with all the
3736 known recipients (which may expose
3737 blind recipients), "add-apparently-to"
3738 to do the same but use Apparently-To:
3739 instead of To: (strongly discouraged
3740 in accordance with IETF standards),
3741 "add-bcc" to add an empty Bcc:
3742 header, or "add-to-undisclosed" to
3744 ``To: undisclosed-recipients:;''.
3745 confSAFE_FILE_ENV SafeFileEnvironment
3746 [undefined] If set, sendmail will do a
3747 chroot() into this directory before
3749 confCOLON_OK_IN_ADDR ColonOkInAddr [True unless Configuration Level > 6]
3750 If set, colons are treated as a regular
3751 character in addresses. If not set,
3752 they are treated as the introducer to
3753 the RFC 822 "group" syntax. Colons are
3754 handled properly in route-addrs. This
3755 option defaults on for V5 and lower
3756 configuration files.
3757 confMAX_QUEUE_RUN_SIZE MaxQueueRunSize [0] If set, limit the maximum size of
3758 any given queue run to this number of
3759 entries. Essentially, this will stop
3760 reading each queue directory after this
3761 number of entries are reached; it does
3762 _not_ pick the highest priority jobs,
3763 so this should be as large as your
3764 system can tolerate. If not set, there
3766 confMAX_QUEUE_CHILDREN MaxQueueChildren
3767 [undefined] Limits the maximum number
3768 of concurrent queue runners active.
3769 This is to keep system resources used
3770 within a reasonable limit. Relates to
3771 Queue Groups and ForkAllJobs.
3772 confMAX_RUNNERS_PER_QUEUE MaxRunnersPerQueue
3773 [1] Only active when MaxQueueChildren
3774 defined. Controls the maximum number
3775 of queue runners (aka queue children)
3776 active at the same time in a work
3777 group. See also MaxQueueChildren.
3778 confDONT_EXPAND_CNAMES DontExpandCnames
3779 [False] If set, $[ ... $] lookups that
3780 do DNS based lookups do not expand
3781 CNAME records. This currently violates
3782 the published standards, but the IETF
3783 seems to be moving toward legalizing
3784 this. For example, if "FTP.Foo.ORG"
3785 is a CNAME for "Cruft.Foo.ORG", then
3786 with this option set a lookup of
3787 "FTP" will return "FTP.Foo.ORG"; if
3788 clear it returns "Cruft.FOO.ORG". N.B.
3789 you may not see any effect until your
3790 downstream neighbors stop doing CNAME
3792 confFROM_LINE UnixFromLine [From $g $d] The From_ line used
3793 when sending to files or programs.
3794 confSINGLE_LINE_FROM_HEADER SingleLineFromHeader
3795 [False] From: lines that have
3796 embedded newlines are unwrapped
3798 confALLOW_BOGUS_HELO AllowBogusHELO [False] Allow HELO SMTP command that
3799 does not include a host name.
3800 confMUST_QUOTE_CHARS MustQuoteChars [.'] Characters to be quoted in a full
3801 name phrase (@,;:\()[] are automatic).
3802 confOPERATORS OperatorChars [.:%@!^/[]+] Address operator
3804 confSMTP_LOGIN_MSG SmtpGreetingMessage
3805 [$j Sendmail $v/$Z; $b]
3806 The initial (spontaneous) SMTP
3807 greeting message. The word "ESMTP"
3808 will be inserted between the first and
3809 second words to convince other
3810 sendmails to try to speak ESMTP.
3811 confDONT_INIT_GROUPS DontInitGroups [False] If set, the initgroups(3)
3812 routine will never be invoked. You
3813 might want to do this if you are
3814 running NIS and you have a large group
3815 map, since this call does a sequential
3816 scan of the map; in a large site this
3817 can cause your ypserv to run
3818 essentially full time. If you set
3819 this, agents run on behalf of users
3820 will only have their primary
3821 (/etc/passwd) group permissions.
3822 confUNSAFE_GROUP_WRITES UnsafeGroupWrites
3823 [False] If set, group-writable
3824 :include: and .forward files are
3825 considered "unsafe", that is, programs
3826 and files cannot be directly referenced
3827 from such files. World-writable files
3828 are always considered unsafe.
3829 confCONNECT_ONLY_TO ConnectOnlyTo [undefined] override connection
3830 address (for testing).
3831 confCONTROL_SOCKET_NAME ControlSocketName
3832 [undefined] Control socket for daemon
3834 confDOUBLE_BOUNCE_ADDRESS DoubleBounceAddress
3835 [postmaster] If an error occurs when
3836 sending an error message, send that
3837 "double bounce" error message to this
3838 address. If it expands to an empty
3839 string, double bounces are dropped.
3840 confDEAD_LETTER_DROP DeadLetterDrop [undefined] Filename to save bounce
3841 messages which could not be returned
3842 to the user or sent to postmaster.
3843 If not set, the queue file will
3845 confRRT_IMPLIES_DSN RrtImpliesDsn [False] Return-Receipt-To: header
3846 implies DSN request.
3847 confRUN_AS_USER RunAsUser [undefined] If set, become this user
3848 when reading and delivering mail.
3849 Causes all file reads (e.g., .forward
3850 and :include: files) to be done as
3851 this user. Also, all programs will
3852 be run as this user, and all output
3853 files will be written as this user.
3854 confMAX_RCPTS_PER_MESSAGE MaxRecipientsPerMessage
3855 [infinite] If set, allow no more than
3856 the specified number of recipients in
3857 an SMTP envelope. Further recipients
3858 receive a 452 error code (i.e., they
3859 are deferred for the next delivery
3861 confBAD_RCPT_THROTTLE BadRcptThrottle [infinite] If set and more than the
3862 specified number of recipients in an
3863 envelope are rejected, sleep for one
3864 second after each rejected RCPT
3866 confDONT_PROBE_INTERFACES DontProbeInterfaces
3867 [False] If set, sendmail will _not_
3868 insert the names and addresses of any
3869 local interfaces into class {w}
3870 (list of known "equivalent" addresses).
3871 If you set this, you must also include
3872 some support for these addresses (e.g.,
3873 in a mailertable entry) -- otherwise,
3874 mail to addresses in this list will
3875 bounce with a configuration error.
3876 If set to "loopback" (without
3877 quotes), sendmail will skip
3878 loopback interfaces (e.g., "lo0").
3879 confPID_FILE PidFile [system dependent] Location of pid
3881 confPROCESS_TITLE_PREFIX ProcessTitlePrefix
3882 [undefined] Prefix string for the
3883 process title shown on 'ps' listings.
3884 confDONT_BLAME_SENDMAIL DontBlameSendmail
3885 [safe] Override sendmail's file
3886 safety checks. This will definitely
3887 compromise system security and should
3888 not be used unless absolutely
3890 confREJECT_MSG - [550 Access denied] The message
3891 given if the access database contains
3892 REJECT in the value portion.
3893 confRELAY_MSG - [550 Relaying denied] The message
3894 given if an unauthorized relaying
3895 attempt is rejected.
3896 confDF_BUFFER_SIZE DataFileBufferSize
3897 [4096] The maximum size of a
3898 memory-buffered data (df) file
3899 before a disk-based file is used.
3900 confXF_BUFFER_SIZE XScriptFileBufferSize
3901 [4096] The maximum size of a
3902 memory-buffered transcript (xf)
3903 file before a disk-based file is
3905 confAUTH_MECHANISMS AuthMechanisms [GSSAPI KERBEROS_V4 DIGEST-MD5
3906 CRAM-MD5] List of authentication
3907 mechanisms for AUTH (separated by
3908 spaces). The advertised list of
3909 authentication mechanisms will be the
3910 intersection of this list and the list
3911 of available mechanisms as determined
3912 by the CYRUS SASL library.
3913 confDEF_AUTH_INFO DefaultAuthInfo [undefined] Name of file that contains
3914 authentication information for
3915 outgoing connections. This file must
3916 contain the user id, the authorization
3917 id, the password (plain text), the
3918 realm to use, and the list of
3919 mechanisms to try, each on a separate
3920 line and must be readable by root (or
3921 the trusted user) only. If no realm
3922 is specified, $j is used. If no
3923 mechanisms are given in the file,
3924 AuthMechanisms is used. Notice: this
3925 option is deprecated and will be
3926 removed in future versions; it doesn't
3927 work for the MSP since it can't read
3928 the file. Use the authinfo ruleset
3929 instead. See also the section SMTP
3931 confAUTH_OPTIONS AuthOptions [undefined] If this option is 'A'
3932 then the AUTH= parameter for the
3933 MAIL FROM command is only issued
3934 when authentication succeeded.
3935 Other values (which should be listed
3936 one after the other without any
3937 intervening characters except for
3938 space or comma) are a, c, d, f, p,
3939 and y. See doc/op/op.me for
3941 confAUTH_MAX_BITS AuthMaxBits [INT_MAX] Limit the maximum encryption
3942 strength for the security layer in
3943 SMTP AUTH (SASL). Default is
3944 essentially unlimited.
3945 confTLS_SRV_OPTIONS TLSSrvOptions If this option is 'V' no client
3946 verification is performed, i.e.,
3947 the server doesn't ask for a
3949 confLDAP_DEFAULT_SPEC LDAPDefaultSpec [undefined] Default map
3950 specification for LDAP maps. The
3951 value should only contain LDAP
3952 specific settings such as "-h host
3953 -p port -d bindDN", etc. The
3954 settings will be used for all LDAP
3955 maps unless they are specified in
3956 the individual map specification
3958 confCACERT_PATH CACertPath [undefined] Path to directory
3960 confCACERT CACertFile [undefined] File containing one CA
3962 confSERVER_CERT ServerCertFile [undefined] File containing the
3963 cert of the server, i.e., this cert
3964 is used when sendmail acts as
3966 confSERVER_KEY ServerKeyFile [undefined] File containing the
3967 private key belonging to the server
3969 confCLIENT_CERT ClientCertFile [undefined] File containing the
3970 cert of the client, i.e., this cert
3971 is used when sendmail acts as
3973 confCLIENT_KEY ClientKeyFile [undefined] File containing the
3974 private key belonging to the client
3976 confDH_PARAMETERS DHParameters [undefined] File containing the
3978 confRAND_FILE RandFile [undefined] File containing random
3979 data (use prefix file:) or the
3980 name of the UNIX socket if EGD is
3981 used (use prefix egd:). STARTTLS
3982 requires this option if the compile
3983 flag HASURANDOM is not set (see
3985 confNICE_QUEUE_RUN NiceQueueRun [undefined] If set, the priority of
3986 queue runners is set the given value
3988 confDIRECT_SUBMISSION_MODIFIERS DirectSubmissionModifiers
3989 [undefined] Defines {daemon_flags}
3990 for direct submissions.
3991 confUSE_MSP UseMSP [false] Use as mail submission
3992 program, see sendmail/SECURITY.
3993 confDELIVER_BY_MIN DeliverByMin [0] Minimum time for Deliver By
3994 SMTP Service Extension (RFC 2852).
3995 confSHARED_MEMORY_KEY SharedMemoryKey [0] Key for shared memory.
3996 confFAST_SPLIT FastSplit [1] If set to a value greater than
3997 zero, the initial MX lookups on
3998 addresses is suppressed when they
3999 are sorted which may result in
4000 faster envelope splitting. If the
4001 mail is submitted directly from the
4002 command line, then the value also
4003 limits the number of processes to
4004 deliver the envelopes.
4005 confMAILBOX_DATABASE MailboxDatabase [pw] Type of lookup to find
4006 information about local mailboxes.
4007 confDEQUOTE_OPTS - [empty] Additional options for the
4009 confINPUT_MAIL_FILTERS InputMailFilters
4010 A comma separated list of filters
4011 which determines which filters and
4012 the invocation sequence are
4013 contacted for incoming SMTP
4014 messages. If none are set, no
4015 filters will be contacted.
4016 confMILTER_LOG_LEVEL Milter.LogLevel [9] Log level for input mail filter
4017 actions, defaults to LogLevel.
4018 confMILTER_MACROS_CONNECT Milter.macros.connect
4019 [j, _, {daemon_name}, {if_name},
4020 {if_addr}] Macros to transmit to
4021 milters when a session connection
4023 confMILTER_MACROS_HELO Milter.macros.helo
4024 [{tls_version}, {cipher},
4025 {cipher_bits}, {cert_subject},
4026 {cert_issuer}] Macros to transmit to
4027 milters after HELO/EHLO command.
4028 confMILTER_MACROS_ENVFROM Milter.macros.envfrom
4029 [i, {auth_type}, {auth_authen},
4030 {auth_ssf}, {auth_author},
4031 {mail_mailer}, {mail_host},
4032 {mail_addr}] Macros to transmit to
4033 milters after MAIL FROM command.
4034 confMILTER_MACROS_ENVRCPT Milter.macros.envrcpt
4035 [{rcpt_mailer}, {rcpt_host},
4036 {rcpt_addr}] Macros to transmit to
4037 milters after RCPT TO command.
4040 See also the description of OSTYPE for some parameters that can be
4041 tweaked (generally pathnames to mailers).
4043 ClientPortOptions and DaemonPortOptions are special cases since multiple
4044 clients/daemons can be defined. This can be done via
4046 CLIENT_OPTIONS(`field1=value1,field2=value2,...')
4047 DAEMON_OPTIONS(`field1=value1,field2=value2,...')
4049 Note that multiple CLIENT_OPTIONS() commands (and therefore multiple
4050 ClientPortOptions settings) are allowed in order to give settings for each
4051 protocol family (e.g., one for Family=inet and one for Family=inet6). A
4052 restriction placed on one family only affects outgoing connections on that
4055 If DAEMON_OPTIONS is not used, then the default is
4057 DAEMON_OPTIONS(`Port=smtp, Name=MTA')
4058 DAEMON_OPTIONS(`Port=587, Name=MSA, M=E')
4060 If you use one DAEMON_OPTIONS macro, it will alter the parameters
4061 of the first of these. The second will still be defaulted; it
4062 represents a "Message Submission Agent" (MSA) as defined by RFC
4063 2476 (see below). To turn off the default definition for the MSA,
4064 use FEATURE(`no_default_msa') (see also FEATURES). If you use
4065 additional DAEMON_OPTIONS macros, they will add additional daemons.
4067 Example 1: To change the port for the SMTP listener, while
4068 still using the MSA default, use
4069 DAEMON_OPTIONS(`Port=925, Name=MTA')
4071 Example 2: To change the port for the MSA daemon, while still
4072 using the default SMTP port, use
4073 FEATURE(`no_default_msa')
4074 DAEMON_OPTIONS(`Name=MTA')
4075 DAEMON_OPTIONS(`Port=987, Name=MSA, M=E')
4077 Note that if the first of those DAEMON_OPTIONS lines were omitted, then
4078 there would be no listener on the standard SMTP port.
4080 Example 3: To listen on both IPv4 and IPv6 interfaces, use
4082 DAEMON_OPTIONS(`Name=MTA-v4, Family=inet')
4083 DAEMON_OPTIONS(`Name=MTA-v6, Family=inet6')
4085 A "Message Submission Agent" still uses all of the same rulesets for
4086 processing the message (and therefore still allows message rejection via
4087 the check_* rulesets). In accordance with the RFC, the MSA will ensure
4088 that all domains in envelope addresses are fully qualified if the message
4089 is relayed to another MTA. It will also enforce the normal address syntax
4090 rules and log error messages. Additionally, by using the M=a modifier you
4091 can require authentication before messages are accepted by the MSA.
4092 Notice: Do NOT use the 'a' modifier on a public accessible MTA! Finally,
4093 the M=E modifier shown above disables ETRN as required by RFC 2476.
4095 Mail filters can be defined using the INPUT_MAIL_FILTER() and MAIL_FILTER()
4098 INPUT_MAIL_FILTER(`sample', `S=local:/var/run/f1.sock')
4099 MAIL_FILTER(`myfilter', `S=inet:3333@localhost')
4101 The INPUT_MAIL_FILTER() command causes the filter(s) to be called in the
4102 same order they were specified by also setting confINPUT_MAIL_FILTERS. A
4103 filter can be defined without adding it to the input filter list by using
4104 MAIL_FILTER() instead of INPUT_MAIL_FILTER() in your .mc file.
4105 Alternatively, you can reset the list of filters and their order by setting
4106 confINPUT_MAIL_FILTERS option after all INPUT_MAIL_FILTER() commands in
4110 +----------------------------+
4111 | MESSAGE SUBMISSION PROGRAM |
4112 +----------------------------+
4114 The purpose of the message submission program (MSP) is explained
4115 in sendmail/SECURITY. This section contains a list of caveats and
4116 a few hints how for those who want to tweak the default configuration
4117 for it (which is installed as submit.cf).
4119 Notice: do not add options/features to submit.mc unless you are
4120 absolutely sure you need them. Options you may want to change
4123 - confTRUSTED_USERS, FEATURE(`use_ct_file'), and confCT_FILE for
4124 avoiding X-Authentication warnings.
4125 - confTIME_ZONE to change it from the default `USE_TZ'.
4126 - confDELIVERY_MODE is set to interactive in msp.m4 instead
4127 of the default background mode.
4128 - FEATURE(stickyhost) and LOCAL_RELAY to send unqualified addresses
4129 to the LOCAL_RELAY instead of the default relay.
4130 - confRAND_FILE if you use STARTTLS and sendmail is not compiled with
4131 the flag HASURANDOM.
4133 The MSP performs hostname canonicalization by default. As also
4134 explained in sendmail/SECURITY, mail may end up for various DNS
4135 related reasons in the MSP queue. This problem can be minimized by
4138 FEATURE(`nocanonify', `canonify_hosts')
4139 define(`confDIRECT_SUBMISSION_MODIFIERS', `C')
4141 See the discussion about nocanonify for possible side effects.
4143 Some things are not intended to work with the MSP. These include
4144 features that influence the delivery process (e.g., mailertable,
4145 aliases), or those that are only important for a SMTP server (e.g.,
4146 virtusertable, DaemonPortOptions, multiple queues). Moreover,
4147 relaxing certain restrictions (RestrictQueueRun, permissions on
4148 queue directory) or adding features (e.g., enabling prog/file mailer)
4149 can cause security problems.
4151 Other things don't work well with the MSP and require tweaking or
4152 workarounds. For example, to allow for client authentication it
4153 is not just sufficient to provide a client certificate and the
4154 corresponding key, but it is also necessary to make the key group
4155 (smmsp) readable and tell sendmail not to complain about that, i.e.,
4157 define(`confDONT_BLAME_SENDMAIL', `GroupReadableKeyFile')
4159 If the MSP should actually use AUTH then the necessary data
4160 should be placed in a map as explained in SMTP AUTHENTICATION:
4162 FEATURE(`authinfo', `DATABASE_MAP_TYPE /etc/mail/msp-authinfo')
4164 /etc/mail/msp-authinfo should contain an entry like:
4166 AuthInfo:127.0.0.1 "U:smmsp" "P:secret" "M:DIGEST-MD5"
4168 The file and the map created by makemap should be owned by smmsp,
4169 its group should be smmsp, and it should have mode 640. The database
4170 used by the MTA for AUTH must have a corresponding entry.
4171 Additionally the MTA must trust this authentication data so the AUTH=
4172 part will be relayed on to the next hop. This can be achieved by
4173 adding the following to your sendmail.mc file:
4177 R$* $: $&{auth_authen}
4180 feature/msp.m4 defines almost all settings for the MSP. Most of
4181 those should not be changed at all. Some of the features and options
4182 can be overridden if really necessary. It is a bit tricky to do
4183 this, because it depends on the actual way the option is defined
4184 in feature/msp.m4. If it is directly defined (i.e., define()) then
4185 the modified value must be defined after
4189 If it is conditionally defined (i.e., ifdef()) then the desired
4190 value must be defined before the FEATURE line in the .mc file.
4191 To see how the options are defined read feature/msp.m4.
4194 +--------------------------+
4195 | FORMAT OF FILES AND MAPS |
4196 +--------------------------+
4198 Files that define classes, i.e., F{classname}, consist of lines
4199 each of which contains a single element of the class. For example,
4200 /etc/mail/local-host-names may have the following content:
4205 Maps must be created using makemap(8) , e.g.,
4207 makemap hash MAP < MAP
4209 In general, a text file from which a map is created contains lines
4214 where 'key' and 'value' are also called LHS and RHS, respectively.
4215 By default, the delimiter between LHS and RHS is a non-empty sequence
4216 of white space characters.
4219 +------------------+
4220 | DIRECTORY LAYOUT |
4221 +------------------+
4223 Within this directory are several subdirectories, to wit:
4225 m4 General support routines. These are typically
4226 very important and should not be changed without
4227 very careful consideration.
4229 cf The configuration files themselves. They have
4230 ".mc" suffixes, and must be run through m4 to
4231 become complete. The resulting output should
4232 have a ".cf" suffix.
4234 ostype Definitions describing a particular operating
4235 system type. These should always be referenced
4236 using the OSTYPE macro in the .mc file. Examples
4237 include "bsd4.3", "bsd4.4", "sunos3.5", and
4240 domain Definitions describing a particular domain, referenced
4241 using the DOMAIN macro in the .mc file. These are
4242 site dependent; for example, "CS.Berkeley.EDU.m4"
4243 describes hosts in the CS.Berkeley.EDU subdomain.
4245 mailer Descriptions of mailers. These are referenced using
4246 the MAILER macro in the .mc file.
4248 sh Shell files used when building the .cf file from the
4249 .mc file in the cf subdirectory.
4251 feature These hold special orthogonal features that you might
4252 want to include. They should be referenced using
4255 hack Local hacks. These can be referenced using the HACK
4256 macro. They shouldn't be of more than voyeuristic
4257 interest outside the .Berkeley.EDU domain, but who knows?
4259 siteconfig Site configuration -- e.g., tables of locally connected
4263 +------------------------+
4264 | ADMINISTRATIVE DETAILS |
4265 +------------------------+
4267 The following sections detail usage of certain internal parts of the
4268 sendmail.cf file. Read them carefully if you are trying to modify
4269 the current model. If you find the above descriptions adequate, these
4270 should be {boring, confusing, tedious, ridiculous} (pick one or more).
4272 RULESETS (* means built in to sendmail)
4275 1 * Sender rewriting
4276 2 * Recipient rewriting
4277 3 * Canonicalization
4279 5 * Local address rewrite (after aliasing)
4280 1x mailer rules (sender qualification)
4281 2x mailer rules (recipient qualification)
4282 3x mailer rules (sender header qualification)
4283 4x mailer rules (recipient header qualification)
4284 5x mailer subroutines (general)
4285 6x mailer subroutines (general)
4286 7x mailer subroutines (general)
4288 90 Mailertable host stripping
4289 96 Bottom half of Ruleset 3 (ruleset 6 in old sendmail)
4290 97 Hook for recursive ruleset 0 call (ruleset 7 in old sendmail)
4291 98 Local part of ruleset 0 (ruleset 8 in old sendmail)
4296 0 local, prog local and program mailers
4297 1 [e]smtp, relay SMTP channel
4298 2 uucp-* UNIX-to-UNIX Copy Program
4299 3 netnews Network News delivery
4300 4 fax Sam Leffler's HylaFAX software
4301 5 mail11 DECnet mailer
4309 D The local domain -- usually not needed
4310 E reserved for X.400 Relay
4313 H mail Hub (for mail clusters)
4318 M Masquerade (who you claim to be)
4323 R Relay (for unqualified names)
4326 U my UUCP name (if you have a UUCP connection)
4327 V UUCP Relay (class {V} hosts)
4328 W UUCP Relay (class {W} hosts)
4329 X UUCP Relay (class {X} hosts)
4330 Y UUCP Relay (all other hosts)
4337 B domains that are candidates for bestmx lookup
4340 E addresses that should not seem to come from $M
4341 F hosts this system forward for
4342 G domains that should be looked up in genericstable
4347 L addresses that should not be forwarded to $R
4348 M domains that should be mapped to $M
4349 N host/domains that should not be mapped to $M
4350 O operators that indicate network operations (cannot be in local names)
4351 P top level pseudo-domains: BITNET, DECNET, FAX, UUCP, etc.
4353 R domains this system is willing to relay (pass anti-spam filters)
4356 U locally connected UUCP hosts
4357 V UUCP hosts connected to relay $V
4358 W UUCP hosts connected to relay $W
4359 X UUCP hosts connected to relay $X
4360 Y locally connected smart UUCP hosts
4361 Z locally connected domain-ized UUCP hosts
4362 . the class containing only a dot
4363 [ the class containing only a left bracket
4368 1 Local host detection and resolution
4369 2 Local Ruleset 3 additions
4370 3 Local Ruleset 0 additions
4371 4 UUCP Ruleset 0 additions
4372 5 locally interpreted names (overrides $R)
4373 6 local configuration (at top of file)
4374 7 mailer definitions
4375 8 DNS based blacklists
4376 9 special local rulesets (1 and 2)
4378 $Revision: 8.623.2.25 $, Last updated $Date: 2003/06/18 18:47:21 $