[exim.git] / doc / doc-docbook / spec.xfpt
1 . /////////////////////////////////////////////////////////////////////////////
2 . This is the primary source of the Exim Manual. It is an xfpt document that is
3 . converted into DocBook XML for subsequent conversion into printable and online
4 . formats. The markup used herein is "standard" xfpt markup, with some extras.
5 . The markup is summarized in a file called Markup.txt.
6 .
7 . WARNING: When you use the .new macro, make sure it appears *before* any
8 . adjacent index items; otherwise you get an empty "paragraph" which causes
9 . unwanted vertical space.
10 . /////////////////////////////////////////////////////////////////////////////
12 .include stdflags
13 .include stdmacs
15 . /////////////////////////////////////////////////////////////////////////////
16 . This outputs the standard DocBook boilerplate.
17 . /////////////////////////////////////////////////////////////////////////////
19 .docbook
21 . /////////////////////////////////////////////////////////////////////////////
22 . These lines are processing instructions for the Simple DocBook Processor that
23 . Philip Hazel has developed as a less cumbersome way of making PostScript and
24 . PDFs than using xmlto and fop. They will be ignored by all other XML
25 . processors.
26 . /////////////////////////////////////////////////////////////////////////////
28 .literal xml
29 <?sdop
30 foot_right_recto="&chaptertitle; (&chapternumber;)"
31 foot_right_verso="&chaptertitle; (&chapternumber;)"
32 toc_chapter_blanks="yes,yes"
33 table_warn_overflow="overprint"
34 ?>
35 .literal off
37 . /////////////////////////////////////////////////////////////////////////////
38 . This generates the outermost <book> element that wraps the entire document.
39 . /////////////////////////////////////////////////////////////////////////////
41 .book
43 . /////////////////////////////////////////////////////////////////////////////
44 . These definitions set some parameters and save some typing.
45 . Update the Copyright year (only) when changing content.
46 . /////////////////////////////////////////////////////////////////////////////
48 .set previousversion "4.93"
49 .include ./local_params
51 .set ACL "access control lists (ACLs)"
52 .set I "&nbsp;&nbsp;&nbsp;&nbsp;"
54 .macro copyyear
55 2019
56 .endmacro
58 . /////////////////////////////////////////////////////////////////////////////
59 . Additional xfpt markup used by this document, over and above the default
60 . provided in the xfpt library.
61 . /////////////////////////////////////////////////////////////////////////////
63 . --- Override the &$ flag to automatically insert a $ with the variable name.
65 .flag &$ $& "<varname>$" "</varname>"
67 . --- Short flags for daggers in option headings. They will always be inside
68 . --- an italic string, but we want the daggers to be in Roman.
70 .flag &!! "</emphasis>&dagger;<emphasis>"
71 .flag &!? "</emphasis>&Dagger;<emphasis>"
73 . --- A macro for an Exim option definition heading, generating a one-line
74 . --- table with four columns. For cases when the option name is given with
75 . --- a space, so that it can be split, a fifth argument is used for the
76 . --- index entry.
78 .macro option
79 .arg 5
80 .oindex "&%$5%&"
81 .endarg
82 .arg -5
83 .oindex "&%$1%&"
84 .endarg
85 .itable all 0 0 4 8* left 6* center 6* center 6* right
86 .row "&%$1%&" "Use: &'$2'&" "Type: &'$3'&" "Default: &'$4'&"
87 .endtable
88 .endmacro
90 . --- A macro for the common 2-column tables. The width of the first column
91 . --- is suitable for the many tables at the start of the main options chapter;
92 . --- a small number of other 2-column tables override it.
94 .macro table2 196pt 254pt
95 .itable none 0 0 2 $1 left $2 left
96 .endmacro
98 . --- A macro that generates .row, but puts &I; at the start of the first
99 . --- argument, thus indenting it. Assume a minimum of two arguments, and
100 . --- allow up to four arguments, which is as many as we'll ever need.
102 .macro irow
103 .arg 4
104 .row "&I;$1" "$2" "$3" "$4"
105 .endarg
106 .arg -4
107 .arg 3
108 .row "&I;$1" "$2" "$3"
109 .endarg
110 .arg -3
111 .row "&I;$1" "$2"
112 .endarg
113 .endarg
114 .endmacro
116 . --- Macros for option, variable, and concept index entries. For a "range"
117 . --- style of entry, use .scindex for the start and .ecindex for the end. The
118 . --- first argument of .scindex and the only argument of .ecindex must be the
119 . --- ID that ties them together.
121 .macro cindex
122 &<indexterm role="concept">&
123 &<primary>&$1&</primary>&
124 .arg 2
125 &<secondary>&$2&</secondary>&
126 .endarg
127 &</indexterm>&
128 .endmacro
130 .macro scindex
131 &<indexterm role="concept" id="$1" class="startofrange">&
132 &<primary>&$2&</primary>&
133 .arg 3
134 &<secondary>&$3&</secondary>&
135 .endarg
136 &</indexterm>&
137 .endmacro
139 .macro ecindex
140 &<indexterm role="concept" startref="$1" class="endofrange"/>&
141 .endmacro
143 .macro oindex
144 &<indexterm role="option">&
145 &<primary>&$1&</primary>&
146 .arg 2
147 &<secondary>&$2&</secondary>&
148 .endarg
149 &</indexterm>&
150 .endmacro
152 .macro vindex
153 &<indexterm role="variable">&
154 &<primary>&$1&</primary>&
155 .arg 2
156 &<secondary>&$2&</secondary>&
157 .endarg
158 &</indexterm>&
159 .endmacro
161 .macro index
162 .echo "** Don't use .index; use .cindex or .oindex or .vindex"
163 .endmacro
164 . ////////////////////////////////////////////////////////////////////////////
167 . ////////////////////////////////////////////////////////////////////////////
168 . The <bookinfo> element is removed from the XML before processing for ASCII
169 . output formats.
170 . ////////////////////////////////////////////////////////////////////////////
172 .literal xml
173 <bookinfo>
174 <title>Specification of the Exim Mail Transfer Agent</title>
175 <titleabbrev>The Exim MTA</titleabbrev>
176 <date>
177 .fulldate
178 </date>
179 <author><firstname>Exim</firstname><surname>Maintainers</surname></author>
180 <authorinitials>EM</authorinitials>
181 <revhistory><revision>
182 .versiondatexml
183 <authorinitials>EM</authorinitials>
184 </revision></revhistory>
185 <copyright><year>
186 .copyyear
187 </year><holder>University of Cambridge</holder></copyright>
188 </bookinfo>
189 .literal off
192 . /////////////////////////////////////////////////////////////////////////////
193 . This chunk of literal XML implements index entries of the form "x, see y" and
194 . "x, see also y". However, the DocBook DTD doesn't allow <indexterm> entries
195 . at the top level, so we have to put the .chapter directive first.
196 . /////////////////////////////////////////////////////////////////////////////
198 .chapter "Introduction" "CHID1"
199 .literal xml
201 <indexterm role="variable">
202 <primary>$1, $2, etc.</primary>
203 <see><emphasis>numerical variables</emphasis></see>
204 </indexterm>
205 <indexterm role="concept">
206 <primary>address</primary>
207 <secondary>rewriting</secondary>
208 <see><emphasis>rewriting</emphasis></see>
209 </indexterm>
210 <indexterm role="concept">
211 <primary>Bounce Address Tag Validation</primary>
212 <see><emphasis>BATV</emphasis></see>
213 </indexterm>
214 <indexterm role="concept">
215 <primary>Client SMTP Authorization</primary>
216 <see><emphasis>CSA</emphasis></see>
217 </indexterm>
218 <indexterm role="concept">
219 <primary>CR character</primary>
220 <see><emphasis>carriage return</emphasis></see>
221 </indexterm>
222 <indexterm role="concept">
223 <primary>CRL</primary>
224 <see><emphasis>certificate revocation list</emphasis></see>
225 </indexterm>
226 <indexterm role="concept">
227 <primary>delivery</primary>
228 <secondary>failure report</secondary>
229 <see><emphasis>bounce message</emphasis></see>
230 </indexterm>
231 <indexterm role="concept">
232 <primary>dialup</primary>
233 <see><emphasis>intermittently connected hosts</emphasis></see>
234 </indexterm>
235 <indexterm role="concept">
236 <primary>exiscan</primary>
237 <see><emphasis>content scanning</emphasis></see>
238 </indexterm>
239 <indexterm role="concept">
240 <primary>failover</primary>
241 <see><emphasis>fallback</emphasis></see>
242 </indexterm>
243 <indexterm role="concept">
244 <primary>fallover</primary>
245 <see><emphasis>fallback</emphasis></see>
246 </indexterm>
247 <indexterm role="concept">
248 <primary>filter</primary>
249 <secondary>Sieve</secondary>
250 <see><emphasis>Sieve filter</emphasis></see>
251 </indexterm>
252 <indexterm role="concept">
253 <primary>ident</primary>
254 <see><emphasis>RFC 1413</emphasis></see>
255 </indexterm>
256 <indexterm role="concept">
257 <primary>LF character</primary>
258 <see><emphasis>linefeed</emphasis></see>
259 </indexterm>
260 <indexterm role="concept">
261 <primary>maximum</primary>
262 <seealso><emphasis>limit</emphasis></seealso>
263 </indexterm>
264 <indexterm role="concept">
265 <primary>monitor</primary>
266 <see><emphasis>Exim monitor</emphasis></see>
267 </indexterm>
268 <indexterm role="concept">
269 <primary>no_<emphasis>xxx</emphasis></primary>
270 <see>entry for xxx</see>
271 </indexterm>
272 <indexterm role="concept">
273 <primary>NUL</primary>
274 <see><emphasis>binary zero</emphasis></see>
275 </indexterm>
276 <indexterm role="concept">
277 <primary>passwd file</primary>
278 <see><emphasis>/etc/passwd</emphasis></see>
279 </indexterm>
280 <indexterm role="concept">
281 <primary>process id</primary>
282 <see><emphasis>pid</emphasis></see>
283 </indexterm>
284 <indexterm role="concept">
285 <primary>RBL</primary>
286 <see><emphasis>DNS list</emphasis></see>
287 </indexterm>
288 <indexterm role="concept">
289 <primary>redirection</primary>
290 <see><emphasis>address redirection</emphasis></see>
291 </indexterm>
292 <indexterm role="concept">
293 <primary>return path</primary>
294 <seealso><emphasis>envelope sender</emphasis></seealso>
295 </indexterm>
296 <indexterm role="concept">
297 <primary>scanning</primary>
298 <see><emphasis>content scanning</emphasis></see>
299 </indexterm>
300 <indexterm role="concept">
301 <primary>SSL</primary>
302 <see><emphasis>TLS</emphasis></see>
303 </indexterm>
304 <indexterm role="concept">
305 <primary>string</primary>
306 <secondary>expansion</secondary>
307 <see><emphasis>expansion</emphasis></see>
308 </indexterm>
309 <indexterm role="concept">
310 <primary>top bit</primary>
311 <see><emphasis>8-bit characters</emphasis></see>
312 </indexterm>
313 <indexterm role="concept">
314 <primary>variables</primary>
315 <see><emphasis>expansion, variables</emphasis></see>
316 </indexterm>
317 <indexterm role="concept">
318 <primary>zero, binary</primary>
319 <see><emphasis>binary zero</emphasis></see>
320 </indexterm>
322 .literal off
325 . /////////////////////////////////////////////////////////////////////////////
326 . This is the real start of the first chapter. See the comment above as to why
327 . we can't have the .chapter line here.
328 . chapter "Introduction"
329 . /////////////////////////////////////////////////////////////////////////////
331 Exim is a mail transfer agent (MTA) for hosts that are running Unix or
332 Unix-like operating systems. It was designed on the assumption that it would be
333 run on hosts that are permanently connected to the Internet. However, it can be
334 used on intermittently connected hosts with suitable configuration adjustments.
336 Configuration files currently exist for the following operating systems: AIX,
337 BSD/OS (aka BSDI), Darwin (Mac OS X), DGUX, Dragonfly, FreeBSD, GNU/Hurd,
338 GNU/Linux, HI-OSF (Hitachi), HI-UX, HP-UX, IRIX, MIPS RISCOS, NetBSD, OpenBSD,
339 OpenUNIX, QNX, SCO, SCO SVR4.2 (aka UNIX-SV), Solaris (aka SunOS5), SunOS4,
340 Tru64-Unix (formerly Digital UNIX, formerly DEC-OSF1), Ultrix, and UnixWare.
341 Some of these operating systems are no longer current and cannot easily be
342 tested, so the configuration files may no longer work in practice.
344 There are also configuration files for compiling Exim in the Cygwin environment
345 that can be installed on systems running Windows. However, this document does
346 not contain any information about running Exim in the Cygwin environment.
348 The terms and conditions for the use and distribution of Exim are contained in
349 the file &_NOTICE_&. Exim is distributed under the terms of the GNU General
350 Public Licence, a copy of which may be found in the file &_LICENCE_&.
352 The use, supply, or promotion of Exim for the purpose of sending bulk,
353 unsolicited electronic mail is incompatible with the basic aims of Exim,
354 which revolve around the free provision of a service that enhances the quality
355 of personal communications. The author of Exim regards indiscriminate
356 mass-mailing as an antisocial, irresponsible abuse of the Internet.
358 Exim owes a great deal to Smail 3 and its author, Ron Karr. Without the
359 experience of running and working on the Smail 3 code, I could never have
360 contemplated starting to write a new MTA. Many of the ideas and user interfaces
361 were originally taken from Smail 3, though the actual code of Exim is entirely
362 new, and has developed far beyond the initial concept.
364 Many people, both in Cambridge and around the world, have contributed to the
365 development and the testing of Exim, and to porting it to various operating
366 systems. I am grateful to them all. The distribution now contains a file called
367 &_ACKNOWLEDGMENTS_&, in which I have started recording the names of
368 contributors.
371 .section "Exim documentation" "SECID1"
372 . Keep this example change bar when updating the documentation!
374 .new
375 .cindex "documentation"
376 This edition of the Exim specification applies to version &version() of Exim.
377 Substantive changes from the &previousversion; edition are marked in some
378 renditions of this document; this paragraph is so marked if the rendition is
379 capable of showing a change indicator.
380 .wen
382 This document is very much a reference manual; it is not a tutorial. The reader
383 is expected to have some familiarity with the SMTP mail transfer protocol and
384 with general Unix system administration. Although there are some discussions
385 and examples in places, the information is mostly organized in a way that makes
386 it easy to look up, rather than in a natural order for sequential reading.
387 Furthermore, this manual aims to cover every aspect of Exim in detail, including
388 a number of rarely-used, special-purpose features that are unlikely to be of
389 very wide interest.
391 .cindex "books about Exim"
392 An &"easier"& discussion of Exim which provides more in-depth explanatory,
393 introductory, and tutorial material can be found in a book entitled &'The Exim
394 SMTP Mail Server'& (second edition, 2007), published by UIT Cambridge
395 (&url(https://www.uit.co.uk/exim-book/)).
397 The book also contains a chapter that gives a general introduction to SMTP and
398 Internet mail. Inevitably, however, the book is unlikely to be fully up-to-date
399 with the latest release of Exim. (Note that the earlier book about Exim,
400 published by O'Reilly, covers Exim 3, and many things have changed in Exim 4.)
402 .cindex "Debian" "information sources"
403 If you are using a Debian distribution of Exim, you will find information about
404 Debian-specific features in the file
405 &_/usr/share/doc/exim4-base/README.Debian_&.
406 The command &(man update-exim.conf)& is another source of Debian-specific
407 information.
409 .cindex "&_doc/NewStuff_&"
410 .cindex "&_doc/ChangeLog_&"
411 .cindex "change log"
412 As Exim develops, there may be features in newer versions that have not
413 yet made it into this document, which is updated only when the most significant
414 digit of the fractional part of the version number changes. Specifications of
415 new features that are not yet in this manual are placed in the file
416 &_doc/NewStuff_& in the Exim distribution.
418 Some features may be classified as &"experimental"&. These may change
419 incompatibly while they are developing, or even be withdrawn. For this reason,
420 they are not documented in this manual. Information about experimental features
421 can be found in the file &_doc/experimental.txt_&.
423 All changes to Exim (whether new features, bug fixes, or other kinds of
424 change) are noted briefly in the file called &_doc/ChangeLog_&.
426 .cindex "&_doc/spec.txt_&"
427 This specification itself is available as an ASCII file in &_doc/spec.txt_& so
428 that it can easily be searched with a text editor. Other files in the &_doc_&
429 directory are:
431 .table2 100pt
432 .row &_OptionLists.txt_& "list of all options in alphabetical order"
433 .row &_dbm.discuss.txt_& "discussion about DBM libraries"
434 .row &_exim.8_& "a man page of Exim's command line options"
435 .row &_experimental.txt_& "documentation of experimental features"
436 .row &_filter.txt_& "specification of the filter language"
437 .row &_Exim3.upgrade_& "upgrade notes from release 2 to release 3"
438 .row &_Exim4.upgrade_& "upgrade notes from release 3 to release 4"
439 .row &_openssl.txt_& "installing a current OpenSSL release"
440 .endtable
442 The main specification and the specification of the filtering language are also
443 available in other formats (HTML, PostScript, PDF, and Texinfo). Section
444 &<<SECTavail>>& below tells you how to get hold of these.
448 .section "FTP site and websites" "SECID2"
449 .cindex "website"
450 .cindex "FTP site"
451 The primary site for Exim source distributions is the &%exim.org%& FTP site,
452 available over HTTPS, HTTP and FTP. These services, and the &%exim.org%&
453 website, are hosted at the University of Cambridge.
455 .cindex "wiki"
456 .cindex "FAQ"
457 As well as Exim distribution tar files, the Exim website contains a number of
458 differently formatted versions of the documentation. A recent addition to the
459 online information is the Exim wiki (&url(https://wiki.exim.org)),
460 which contains what used to be a separate FAQ, as well as various other
461 examples, tips, and know-how that have been contributed by Exim users.
462 The wiki site should always redirect to the correct place, which is currently
463 provided by GitHub, and is open to editing by anyone with a GitHub account.
465 .cindex Bugzilla
466 An Exim Bugzilla exists at &url(https://bugs.exim.org). You can use
467 this to report bugs, and also to add items to the wish list. Please search
468 first to check that you are not duplicating a previous entry.
469 Please do not ask for configuration help in the bug-tracker.
472 .section "Mailing lists" "SECID3"
473 .cindex "mailing lists" "for Exim users"
474 The following Exim mailing lists exist:
476 .table2 140pt
477 .row &'exim-announce@exim.org'& "Moderated, low volume announcements list"
478 .row &'exim-users@exim.org'& "General discussion list"
479 .row &'exim-dev@exim.org'& "Discussion of bugs, enhancements, etc."
480 .row &'exim-cvs@exim.org'& "Automated commit messages from the VCS"
481 .endtable
483 You can subscribe to these lists, change your existing subscriptions, and view
484 or search the archives via the mailing lists link on the Exim home page.
485 .cindex "Debian" "mailing list for"
486 If you are using a Debian distribution of Exim, you may wish to subscribe to
487 the Debian-specific mailing list &'pkg-exim4-users@lists.alioth.debian.org'&
488 via this web page:
489 .display
490 &url(https://alioth-lists.debian.net/cgi-bin/mailman/listinfo/pkg-exim4-users)
491 .endd
492 Please ask Debian-specific questions on that list and not on the general Exim
493 lists.
495 .section "Bug reports" "SECID5"
496 .cindex "bug reports"
497 .cindex "reporting bugs"
498 Reports of obvious bugs can be emailed to &'bugs@exim.org'& or reported
499 via the Bugzilla (&url(https://bugs.exim.org)). However, if you are unsure
500 whether some behaviour is a bug or not, the best thing to do is to post a
501 message to the &'exim-dev'& mailing list and have it discussed.
505 .section "Where to find the Exim distribution" "SECTavail"
506 .cindex "FTP site"
507 .cindex "HTTPS download site"
508 .cindex "distribution" "FTP site"
509 .cindex "distribution" "https site"
510 The master distribution site for the Exim distribution is
511 .display
512 &url(https://downloads.exim.org/)
513 .endd
514 The service is available over HTTPS, HTTP and FTP.
515 We encourage people to migrate to HTTPS.
517 The content served at &url(https://downloads.exim.org/) is identical to the
518 content served at &url(https://ftp.exim.org/pub/exim) and
519 &url(ftp://ftp.exim.org/pub/exim).
521 If accessing via a hostname containing &'ftp'&, then the file references that
522 follow are relative to the &_exim_& directories at these sites.
523 If accessing via the hostname &'downloads'& then the subdirectories described
524 here are top-level directories.
526 There are now quite a number of independent mirror sites around
527 the world. Those that I know about are listed in the file called &_Mirrors_&.
529 Within the top exim directory there are subdirectories called &_exim3_& (for
530 previous Exim 3 distributions), &_exim4_& (for the latest Exim 4
531 distributions), and &_Testing_& for testing versions. In the &_exim4_&
532 subdirectory, the current release can always be found in files called
533 .display
534 &_exim-n.nn.tar.xz_&
535 &_exim-n.nn.tar.gz_&
536 &_exim-n.nn.tar.bz2_&
537 .endd
538 where &'n.nn'& is the highest such version number in the directory. The three
539 files contain identical data; the only difference is the type of compression.
540 The &_.xz_& file is usually the smallest, while the &_.gz_& file is the
541 most portable to old systems.
543 .cindex "distribution" "signing details"
544 .cindex "distribution" "public key"
545 .cindex "public key for signed distribution"
546 The distributions will be PGP signed by an individual key of the Release
547 Coordinator. This key will have a uid containing an email address in the
548 &'exim.org'& domain and will have signatures from other people, including
549 other Exim maintainers. We expect that the key will be in the "strong set" of
550 PGP keys. There should be a trust path to that key from the Exim Maintainer's
551 PGP keys, a version of which can be found in the release directory in the file
552 &_Exim-Maintainers-Keyring.asc_&. All keys used will be available in public keyserver pools,
553 such as &'pool.sks-keyservers.net'&.
555 At the time of the last update, releases were being made by Jeremy Harris and signed
556 with key &'0xBCE58C8CE41F32DF'&. Other recent keys used for signing are those
557 of Heiko Schlittermann, &'0x26101B62F69376CE'&,
558 and of Phil Pennock, &'0x4D1E900E14C1CC04'&.
560 The signatures for the tar bundles are in:
561 .display
562 &_exim-n.nn.tar.xz.asc_&
563 &_exim-n.nn.tar.gz.asc_&
564 &_exim-n.nn.tar.bz2.asc_&
565 .endd
566 For each released version, the log of changes is made available in a
567 separate file in the directory &_ChangeLogs_& so that it is possible to
568 find out what has changed without having to download the entire distribution.
570 .cindex "documentation" "available formats"
571 The main distribution contains ASCII versions of this specification and other
572 documentation; other formats of the documents are available in separate files
573 inside the &_exim4_& directory of the FTP site:
574 .display
575 &_exim-html-n.nn.tar.gz_&
576 &_exim-pdf-n.nn.tar.gz_&
577 &_exim-postscript-n.nn.tar.gz_&
578 &_exim-texinfo-n.nn.tar.gz_&
579 .endd
580 These tar files contain only the &_doc_& directory, not the complete
581 distribution, and are also available in &_.bz2_& and &_.xz_& forms.
584 .section "Limitations" "SECID6"
585 .ilist
586 .cindex "limitations of Exim"
587 .cindex "bang paths" "not handled by Exim"
588 Exim is designed for use as an Internet MTA, and therefore handles addresses in
589 RFC 2822 domain format only. It cannot handle UUCP &"bang paths"&, though
590 simple two-component bang paths can be converted by a straightforward rewriting
591 configuration. This restriction does not prevent Exim from being interfaced to
592 UUCP as a transport mechanism, provided that domain addresses are used.
593 .next
594 .cindex "domainless addresses"
595 .cindex "address" "without domain"
596 Exim insists that every address it handles has a domain attached. For incoming
597 local messages, domainless addresses are automatically qualified with a
598 configured domain value. Configuration options specify from which remote
599 systems unqualified addresses are acceptable. These are then qualified on
600 arrival.
601 .next
602 .cindex "transport" "external"
603 .cindex "external transports"
604 The only external transport mechanisms that are currently implemented are SMTP
605 and LMTP over a TCP/IP network (including support for IPv6). However, a pipe
606 transport is available, and there are facilities for writing messages to files
607 and pipes, optionally in &'batched SMTP'& format; these facilities can be used
608 to send messages to other transport mechanisms such as UUCP, provided they can
609 handle domain-style addresses. Batched SMTP input is also catered for.
610 .next
611 Exim is not designed for storing mail for dial-in hosts. When the volumes of
612 such mail are large, it is better to get the messages &"delivered"& into files
613 (that is, off Exim's queue) and subsequently passed on to the dial-in hosts by
614 other means.
615 .next
616 Although Exim does have basic facilities for scanning incoming messages, these
617 are not comprehensive enough to do full virus or spam scanning. Such operations
618 are best carried out using additional specialized software packages. If you
619 compile Exim with the content-scanning extension, straightforward interfaces to
620 a number of common scanners are provided.
621 .endlist
624 .section "Runtime configuration" "SECID7"
625 Exim's runtime configuration is held in a single text file that is divided
626 into a number of sections. The entries in this file consist of keywords and
627 values, in the style of Smail 3 configuration files. A default configuration
628 file which is suitable for simple online installations is provided in the
629 distribution, and is described in chapter &<<CHAPdefconfil>>& below.
632 .section "Calling interface" "SECID8"
633 .cindex "Sendmail compatibility" "command line interface"
634 Like many MTAs, Exim has adopted the Sendmail command line interface so that it
635 can be a straight replacement for &_/usr/lib/sendmail_& or
636 &_/usr/sbin/sendmail_& when sending mail, but you do not need to know anything
637 about Sendmail in order to run Exim. For actions other than sending messages,
638 Sendmail-compatible options also exist, but those that produce output (for
639 example, &%-bp%&, which lists the messages in the queue) do so in Exim's own
640 format. There are also some additional options that are compatible with Smail
641 3, and some further options that are new to Exim. Chapter &<<CHAPcommandline>>&
642 documents all Exim's command line options. This information is automatically
643 made into the man page that forms part of the Exim distribution.
645 Control of messages in the queue can be done via certain privileged command
646 line options. There is also an optional monitor program called &'eximon'&,
647 which displays current information in an X window, and which contains a menu
648 interface to Exim's command line administration options.
652 .section "Terminology" "SECID9"
653 .cindex "terminology definitions"
654 .cindex "body of message" "definition of"
655 The &'body'& of a message is the actual data that the sender wants to transmit.
656 It is the last part of a message and is separated from the &'header'& (see
657 below) by a blank line.
659 .cindex "bounce message" "definition of"
660 When a message cannot be delivered, it is normally returned to the sender in a
661 delivery failure message or a &"non-delivery report"& (NDR). The term
662 &'bounce'& is commonly used for this action, and the error reports are often
663 called &'bounce messages'&. This is a convenient shorthand for &"delivery
664 failure error report"&. Such messages have an empty sender address in the
665 message's &'envelope'& (see below) to ensure that they cannot themselves give
666 rise to further bounce messages.
668 The term &'default'& appears frequently in this manual. It is used to qualify a
669 value which is used in the absence of any setting in the configuration. It may
670 also qualify an action which is taken unless a configuration setting specifies
671 otherwise.
673 The term &'defer'& is used when the delivery of a message to a specific
674 destination cannot immediately take place for some reason (a remote host may be
675 down, or a user's local mailbox may be full). Such deliveries are &'deferred'&
676 until a later time.
678 The word &'domain'& is sometimes used to mean all but the first component of a
679 host's name. It is &'not'& used in that sense here, where it normally refers to
680 the part of an email address following the @ sign.
682 .cindex "envelope, definition of"
683 .cindex "sender" "definition of"
684 A message in transit has an associated &'envelope'&, as well as a header and a
685 body. The envelope contains a sender address (to which bounce messages should
686 be delivered), and any number of recipient addresses. References to the
687 sender or the recipients of a message usually mean the addresses in the
688 envelope. An MTA uses these addresses for delivery, and for returning bounce
689 messages, not the addresses that appear in the header lines.
691 .cindex "message" "header, definition of"
692 .cindex "header section" "definition of"
693 The &'header'& of a message is the first part of a message's text, consisting
694 of a number of lines, each of which has a name such as &'From:'&, &'To:'&,
695 &'Subject:'&, etc. Long header lines can be split over several text lines by
696 indenting the continuations. The header is separated from the body by a blank
697 line.
699 .cindex "local part" "definition of"
700 .cindex "domain" "definition of"
701 The term &'local part'&, which is taken from RFC 2822, is used to refer to the
702 part of an email address that precedes the @ sign. The part that follows the
703 @ sign is called the &'domain'& or &'mail domain'&.
705 .cindex "local delivery" "definition of"
706 .cindex "remote delivery, definition of"
707 The terms &'local delivery'& and &'remote delivery'& are used to distinguish
708 delivery to a file or a pipe on the local host from delivery by SMTP over
709 TCP/IP to another host. As far as Exim is concerned, all hosts other than the
710 host it is running on are &'remote'&.
712 .cindex "return path" "definition of"
713 &'Return path'& is another name that is used for the sender address in a
714 message's envelope.
716 .cindex "queue" "definition of"
717 The term &'queue'& is used to refer to the set of messages awaiting delivery
718 because this term is in widespread use in the context of MTAs. However, in
719 Exim's case, the reality is more like a pool than a queue, because there is
720 normally no ordering of waiting messages.
722 .cindex "queue runner" "definition of"
723 The term &'queue runner'& is used to describe a process that scans the queue
724 and attempts to deliver those messages whose retry times have come. This term
725 is used by other MTAs and also relates to the command &%runq%&, but in Exim
726 the waiting messages are normally processed in an unpredictable order.
728 .cindex "spool directory" "definition of"
729 The term &'spool directory'& is used for a directory in which Exim keeps the
730 messages in its queue &-- that is, those that it is in the process of
731 delivering. This should not be confused with the directory in which local
732 mailboxes are stored, which is called a &"spool directory"& by some people. In
733 the Exim documentation, &"spool"& is always used in the first sense.
740 . ////////////////////////////////////////////////////////////////////////////
741 . ////////////////////////////////////////////////////////////////////////////
743 .chapter "Incorporated code" "CHID2"
744 .cindex "incorporated code"
745 .cindex "regular expressions" "library"
746 .cindex "PCRE"
747 .cindex "OpenDMARC"
748 A number of pieces of external code are included in the Exim distribution.
750 .ilist
751 Regular expressions are supported in the main Exim program and in the
752 Exim monitor using the freely-distributable PCRE library, copyright
753 &copy; University of Cambridge. The source to PCRE is no longer shipped with
754 Exim, so you will need to use the version of PCRE shipped with your system,
755 or obtain and install the full version of the library from
756 &url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre).
757 .next
758 .cindex "cdb" "acknowledgment"
759 Support for the cdb (Constant DataBase) lookup method is provided by code
760 contributed by Nigel Metheringham of (at the time he contributed it) Planet
761 Online Ltd. The implementation is completely contained within the code of Exim.
762 It does not link against an external cdb library. The code contains the
763 following statements:
765 .blockquote
766 Copyright &copy; 1998 Nigel Metheringham, Planet Online Ltd
768 This program is free software; you can redistribute it and/or modify it under
769 the terms of the GNU General Public License as published by the Free Software
770 Foundation; either version 2 of the License, or (at your option) any later
771 version.
772 This code implements Dan Bernstein's Constant DataBase (cdb) spec. Information,
773 the spec and sample code for cdb can be obtained from
774 &url(https://cr.yp.to/cdb.html). This implementation borrows
775 some code from Dan Bernstein's implementation (which has no license
776 restrictions applied to it).
777 .endblockquote
778 .next
779 .cindex "SPA authentication"
780 .cindex "Samba project"
781 .cindex "Microsoft Secure Password Authentication"
782 Client support for Microsoft's &'Secure Password Authentication'& is provided
783 by code contributed by Marc Prud'hommeaux. Server support was contributed by
784 Tom Kistner. This includes code taken from the Samba project, which is released
785 under the Gnu GPL.
786 .next
787 .cindex "Cyrus"
788 .cindex "&'pwcheck'& daemon"
789 .cindex "&'pwauthd'& daemon"
790 Support for calling the Cyrus &'pwcheck'& and &'saslauthd'& daemons is provided
791 by code taken from the Cyrus-SASL library and adapted by Alexander S.
792 Sabourenkov. The permission notice appears below, in accordance with the
793 conditions expressed therein.
795 .blockquote
796 Copyright &copy; 2001 Carnegie Mellon University. All rights reserved.
798 Redistribution and use in source and binary forms, with or without
799 modification, are permitted provided that the following conditions
800 are met:
802 .olist
803 Redistributions of source code must retain the above copyright
804 notice, this list of conditions and the following disclaimer.
805 .next
806 Redistributions in binary form must reproduce the above copyright
807 notice, this list of conditions and the following disclaimer in
808 the documentation and/or other materials provided with the
809 distribution.
810 .next
811 The name &"Carnegie Mellon University"& must not be used to
812 endorse or promote products derived from this software without
813 prior written permission. For permission or any other legal
814 details, please contact
815 .display
816 Office of Technology Transfer
817 Carnegie Mellon University
818 5000 Forbes Avenue
819 Pittsburgh, PA 15213-3890
820 (412) 268-4387, fax: (412) 268-7395
821 tech-transfer@andrew.cmu.edu
822 .endd
823 .next
824 Redistributions of any form whatsoever must retain the following
825 acknowledgment:
827 &"This product includes software developed by Computing Services
828 at Carnegie Mellon University (&url(https://www.cmu.edu/computing/)."&
837 .endlist
838 .endblockquote
840 .next
841 .cindex "Exim monitor" "acknowledgment"
842 .cindex "X-windows"
843 .cindex "Athena"
844 The Exim Monitor program, which is an X-Window application, includes
845 modified versions of the Athena StripChart and TextPop widgets.
846 This code is copyright by DEC and MIT, and their permission notice appears
847 below, in accordance with the conditions expressed therein.
849 .blockquote
850 Copyright 1987, 1988 by Digital Equipment Corporation, Maynard, Massachusetts,
851 and the Massachusetts Institute of Technology, Cambridge, Massachusetts.
853 All Rights Reserved
855 Permission to use, copy, modify, and distribute this software and its
856 documentation for any purpose and without fee is hereby granted,
857 provided that the above copyright notice appear in all copies and that
858 both that copyright notice and this permission notice appear in
859 supporting documentation, and that the names of Digital or MIT not be
860 used in advertising or publicity pertaining to distribution of the
861 software without specific, written prior permission.
870 .endblockquote
872 .next
873 .cindex "opendmarc" "acknowledgment"
874 The DMARC implementation uses the OpenDMARC library which is Copyrighted by
875 The Trusted Domain Project. Portions of Exim source which use OpenDMARC
876 derived code are indicated in the respective source files. The full OpenDMARC
877 license is provided in the LICENSE.opendmarc file contained in the distributed
878 source code.
880 .next
881 Many people have contributed code fragments, some large, some small, that were
882 not covered by any specific license requirements. It is assumed that the
883 contributors are happy to see their code incorporated into Exim under the GPL.
884 .endlist
890 . ////////////////////////////////////////////////////////////////////////////
891 . ////////////////////////////////////////////////////////////////////////////
893 .chapter "How Exim receives and delivers mail" "CHID11" &&&
894 "Receiving and delivering mail"
897 .section "Overall philosophy" "SECID10"
898 .cindex "design philosophy"
899 Exim is designed to work efficiently on systems that are permanently connected
900 to the Internet and are handling a general mix of mail. In such circumstances,
901 most messages can be delivered immediately. Consequently, Exim does not
902 maintain independent queues of messages for specific domains or hosts, though
903 it does try to send several messages in a single SMTP connection after a host
904 has been down, and it also maintains per-host retry information.
907 .section "Policy control" "SECID11"
908 .cindex "policy control" "overview"
909 Policy controls are now an important feature of MTAs that are connected to the
910 Internet. Perhaps their most important job is to stop MTAs from being abused as
911 &"open relays"& by misguided individuals who send out vast amounts of
912 unsolicited junk and want to disguise its source. Exim provides flexible
913 facilities for specifying policy controls on incoming mail:
915 .ilist
916 .cindex "&ACL;" "introduction"
917 Exim 4 (unlike previous versions of Exim) implements policy controls on
918 incoming mail by means of &'Access Control Lists'& (ACLs). Each list is a
919 series of statements that may either grant or deny access. ACLs can be used at
920 several places in the SMTP dialogue while receiving a message from a remote
921 host. However, the most common places are after each RCPT command, and at the
922 very end of the message. The sysadmin can specify conditions for accepting or
923 rejecting individual recipients or the entire message, respectively, at these
924 two points (see chapter &<<CHAPACL>>&). Denial of access results in an SMTP
925 error code.
926 .next
927 An ACL is also available for locally generated, non-SMTP messages. In this
928 case, the only available actions are to accept or deny the entire message.
929 .next
930 When Exim is compiled with the content-scanning extension, facilities are
931 provided in the ACL mechanism for passing the message to external virus and/or
932 spam scanning software. The result of such a scan is passed back to the ACL,
933 which can then use it to decide what to do with the message.
934 .next
935 When a message has been received, either from a remote host or from the local
936 host, but before the final acknowledgment has been sent, a locally supplied C
937 function called &[local_scan()]& can be run to inspect the message and decide
938 whether to accept it or not (see chapter &<<CHAPlocalscan>>&). If the message
939 is accepted, the list of recipients can be modified by the function.
940 .next
941 Using the &[local_scan()]& mechanism is another way of calling external scanner
942 software. The &%SA-Exim%& add-on package works this way. It does not require
943 Exim to be compiled with the content-scanning extension.
944 .next
945 After a message has been accepted, a further checking mechanism is available in
946 the form of the &'system filter'& (see chapter &<<CHAPsystemfilter>>&). This
947 runs at the start of every delivery process.
948 .endlist
952 .section "User filters" "SECID12"
953 .cindex "filter" "introduction"
954 .cindex "Sieve filter"
955 In a conventional Exim configuration, users are able to run private filters by
956 setting up appropriate &_.forward_& files in their home directories. See
957 chapter &<<CHAPredirect>>& (about the &(redirect)& router) for the
958 configuration needed to support this, and the separate document entitled
959 &'Exim's interfaces to mail filtering'& for user details. Two different kinds
960 of filtering are available:
962 .ilist
963 Sieve filters are written in the standard filtering language that is defined
964 by RFC 3028.
965 .next
966 Exim filters are written in a syntax that is unique to Exim, but which is more
967 powerful than Sieve, which it pre-dates.
968 .endlist
970 User filters are run as part of the routing process, described below.
974 .section "Message identification" "SECTmessiden"
975 .cindex "message ids" "details of format"
976 .cindex "format" "of message id"
977 .cindex "id of message"
978 .cindex "base62"
979 .cindex "base36"
980 .cindex "Darwin"
981 .cindex "Cygwin"
982 Every message handled by Exim is given a &'message id'& which is sixteen
983 characters long. It is divided into three parts, separated by hyphens, for
984 example &`16VDhn-0001bo-D3`&. Each part is a sequence of letters and digits,
985 normally encoding numbers in base 62. However, in the Darwin operating
986 system (Mac OS X) and when Exim is compiled to run under Cygwin, base 36
987 (avoiding the use of lower case letters) is used instead, because the message
988 id is used to construct filenames, and the names of files in those systems are
989 not always case-sensitive.
991 .cindex "pid (process id)" "re-use of"
992 The detail of the contents of the message id have changed as Exim has evolved.
993 Earlier versions relied on the operating system not re-using a process id (pid)
994 within one second. On modern operating systems, this assumption can no longer
995 be made, so the algorithm had to be changed. To retain backward compatibility,
996 the format of the message id was retained, which is why the following rules are
997 somewhat eccentric:
999 .ilist
1000 The first six characters of the message id are the time at which the message
1001 started to be received, to a granularity of one second. That is, this field
1002 contains the number of seconds since the start of the epoch (the normal Unix
1003 way of representing the date and time of day).
1004 .next
1005 After the first hyphen, the next six characters are the id of the process that
1006 received the message.
1007 .next
1008 There are two different possibilities for the final two characters:
1009 .olist
1010 .oindex "&%localhost_number%&"
1011 If &%localhost_number%& is not set, this value is the fractional part of the
1012 time of reception, normally in units of 1/2000 of a second, but for systems
1013 that must use base 36 instead of base 62 (because of case-insensitive file
1014 systems), the units are 1/1000 of a second.
1015 .next
1016 If &%localhost_number%& is set, it is multiplied by 200 (100) and added to
1017 the fractional part of the time, which in this case is in units of 1/200
1018 (1/100) of a second.
1019 .endlist
1020 .endlist
1022 After a message has been received, Exim waits for the clock to tick at the
1023 appropriate resolution before proceeding, so that if another message is
1024 received by the same process, or by another process with the same (re-used)
1025 pid, it is guaranteed that the time will be different. In most cases, the clock
1026 will already have ticked while the message was being received.
1029 .section "Receiving mail" "SECID13"
1030 .cindex "receiving mail"
1031 .cindex "message" "reception"
1032 The only way Exim can receive mail from another host is using SMTP over
1033 TCP/IP, in which case the sender and recipient addresses are transferred using
1034 SMTP commands. However, from a locally running process (such as a user's MUA),
1035 there are several possibilities:
1037 .ilist
1038 If the process runs Exim with the &%-bm%& option, the message is read
1039 non-interactively (usually via a pipe), with the recipients taken from the
1040 command line, or from the body of the message if &%-t%& is also used.
1041 .next
1042 If the process runs Exim with the &%-bS%& option, the message is also read
1043 non-interactively, but in this case the recipients are listed at the start of
1044 the message in a series of SMTP RCPT commands, terminated by a DATA
1045 command. This is called &"batch SMTP"& format,
1046 but it isn't really SMTP. The SMTP commands are just another way of passing
1047 envelope addresses in a non-interactive submission.
1048 .next
1049 If the process runs Exim with the &%-bs%& option, the message is read
1050 interactively, using the SMTP protocol. A two-way pipe is normally used for
1051 passing data between the local process and the Exim process.
1052 This is &"real"& SMTP and is handled in the same way as SMTP over TCP/IP. For
1053 example, the ACLs for SMTP commands are used for this form of submission.
1054 .next
1055 A local process may also make a TCP/IP call to the host's loopback address
1056 ( or any other of its IP addresses. When receiving messages, Exim
1057 does not treat the loopback address specially. It treats all such connections
1058 in the same way as connections from other hosts.
1059 .endlist
1062 .cindex "message sender, constructed by Exim"
1063 .cindex "sender" "constructed by Exim"
1064 In the three cases that do not involve TCP/IP, the sender address is
1065 constructed from the login name of the user that called Exim and a default
1066 qualification domain (which can be set by the &%qualify_domain%& configuration
1067 option). For local or batch SMTP, a sender address that is passed using the
1068 SMTP MAIL command is ignored. However, the system administrator may allow
1069 certain users (&"trusted users"&) to specify a different sender addresses
1070 unconditionally, or all users to specify certain forms of different sender
1071 address. The &%-f%& option or the SMTP MAIL command is used to specify these
1072 different addresses. See section &<<SECTtrustedadmin>>& for details of trusted
1073 users, and the &%untrusted_set_sender%& option for a way of allowing untrusted
1074 users to change sender addresses.
1076 Messages received by either of the non-interactive mechanisms are subject to
1077 checking by the non-SMTP ACL if one is defined. Messages received using SMTP
1078 (either over TCP/IP or interacting with a local process) can be checked by a
1079 number of ACLs that operate at different times during the SMTP session. Either
1080 individual recipients or the entire message can be rejected if local policy
1081 requirements are not met. The &[local_scan()]& function (see chapter
1082 &<<CHAPlocalscan>>&) is run for all incoming messages.
1084 Exim can be configured not to start a delivery process when a message is
1085 received; this can be unconditional, or depend on the number of incoming SMTP
1086 connections or the system load. In these situations, new messages wait on the
1087 queue until a queue runner process picks them up. However, in standard
1088 configurations under normal conditions, delivery is started as soon as a
1089 message is received.
1095 .section "Handling an incoming message" "SECID14"
1096 .cindex "spool directory" "files that hold a message"
1097 .cindex "file" "how a message is held"
1098 When Exim accepts a message, it writes two files in its spool directory. The
1099 first contains the envelope information, the current status of the message, and
1100 the header lines, and the second contains the body of the message. The names of
1101 the two spool files consist of the message id, followed by &`-H`& for the
1102 file containing the envelope and header, and &`-D`& for the data file.
1104 .cindex "spool directory" "&_input_& sub-directory"
1105 By default, all these message files are held in a single directory called
1106 &_input_& inside the general Exim spool directory. Some operating systems do
1107 not perform very well if the number of files in a directory gets large; to
1108 improve performance in such cases, the &%split_spool_directory%& option can be
1109 used. This causes Exim to split up the input files into 62 sub-directories
1110 whose names are single letters or digits. When this is done, the queue is
1111 processed one sub-directory at a time instead of all at once, which can improve
1112 overall performance even when there are not enough files in each directory to
1113 affect file system performance.
1115 The envelope information consists of the address of the message's sender and
1116 the addresses of the recipients. This information is entirely separate from
1117 any addresses contained in the header lines. The status of the message includes
1118 a list of recipients who have already received the message. The format of the
1119 first spool file is described in chapter &<<CHAPspool>>&.
1121 .cindex "rewriting" "addresses"
1122 Address rewriting that is specified in the rewrite section of the configuration
1123 (see chapter &<<CHAPrewrite>>&) is done once and for all on incoming addresses,
1124 both in the header lines and the envelope, at the time the message is accepted.
1125 If during the course of delivery additional addresses are generated (for
1126 example, via aliasing), these new addresses are rewritten as soon as they are
1127 generated. At the time a message is actually delivered (transported) further
1128 rewriting can take place; because this is a transport option, it can be
1129 different for different forms of delivery. It is also possible to specify the
1130 addition or removal of certain header lines at the time the message is
1131 delivered (see chapters &<<CHAProutergeneric>>& and
1132 &<<CHAPtransportgeneric>>&).
1136 .section "Life of a message" "SECID15"
1137 .cindex "message" "life of"
1138 .cindex "message" "frozen"
1139 A message remains in the spool directory until it is completely delivered to
1140 its recipients or to an error address, or until it is deleted by an
1141 administrator or by the user who originally created it. In cases when delivery
1142 cannot proceed &-- for example when a message can neither be delivered to its
1143 recipients nor returned to its sender, the message is marked &"frozen"& on the
1144 spool, and no more deliveries are attempted.
1146 .cindex "frozen messages" "thawing"
1147 .cindex "message" "thawing frozen"
1148 An administrator can &"thaw"& such messages when the problem has been
1149 corrected, and can also freeze individual messages by hand if necessary. In
1150 addition, an administrator can force a delivery error, causing a bounce message
1151 to be sent.
1153 .oindex "&%timeout_frozen_after%&"
1154 .oindex "&%ignore_bounce_errors_after%&"
1155 There are options called &%ignore_bounce_errors_after%& and
1156 &%timeout_frozen_after%&, which discard frozen messages after a certain time.
1157 The first applies only to frozen bounces, the second to all frozen messages.
1159 .cindex "message" "log file for"
1160 .cindex "log" "file for each message"
1161 While Exim is working on a message, it writes information about each delivery
1162 attempt to its main log file. This includes successful, unsuccessful, and
1163 delayed deliveries for each recipient (see chapter &<<CHAPlog>>&). The log
1164 lines are also written to a separate &'message log'& file for each message.
1165 These logs are solely for the benefit of the administrator and are normally
1166 deleted along with the spool files when processing of a message is complete.
1167 The use of individual message logs can be disabled by setting
1168 &%no_message_logs%&; this might give an improvement in performance on very busy
1169 systems.
1171 .cindex "journal file"
1172 .cindex "file" "journal"
1173 All the information Exim itself needs to set up a delivery is kept in the first
1174 spool file, along with the header lines. When a successful delivery occurs, the
1175 address is immediately written at the end of a journal file, whose name is the
1176 message id followed by &`-J`&. At the end of a delivery run, if there are some
1177 addresses left to be tried again later, the first spool file (the &`-H`& file)
1178 is updated to indicate which these are, and the journal file is then deleted.
1179 Updating the spool file is done by writing a new file and renaming it, to
1180 minimize the possibility of data loss.
1182 Should the system or Exim crash after a successful delivery but before
1183 the spool file has been updated, the journal is left lying around. The next
1184 time Exim attempts to deliver the message, it reads the journal file and
1185 updates the spool file before proceeding. This minimizes the chances of double
1186 deliveries caused by crashes.
1190 .section "Processing an address for delivery" "SECTprocaddress"
1191 .cindex "drivers" "definition of"
1192 .cindex "router" "definition of"
1193 .cindex "transport" "definition of"
1194 The main delivery processing elements of Exim are called &'routers'& and
1195 &'transports'&, and collectively these are known as &'drivers'&. Code for a
1196 number of them is provided in the source distribution, and compile-time options
1197 specify which ones are included in the binary. Runtime options specify which
1198 ones are actually used for delivering messages.
1200 .cindex "drivers" "instance definition"
1201 Each driver that is specified in the runtime configuration is an &'instance'&
1202 of that particular driver type. Multiple instances are allowed; for example,
1203 you can set up several different &(smtp)& transports, each with different
1204 option values that might specify different ports or different timeouts. Each
1205 instance has its own identifying name. In what follows we will normally use the
1206 instance name when discussing one particular instance (that is, one specific
1207 configuration of the driver), and the generic driver name when discussing
1208 the driver's features in general.
1210 A &'router'& is a driver that operates on an address, either determining how
1211 its delivery should happen, by assigning it to a specific transport, or
1212 converting the address into one or more new addresses (for example, via an
1213 alias file). A router may also explicitly choose to fail an address, causing it
1214 to be bounced.
1216 A &'transport'& is a driver that transmits a copy of the message from Exim's
1217 spool to some destination. There are two kinds of transport: for a &'local'&
1218 transport, the destination is a file or a pipe on the local host, whereas for a
1219 &'remote'& transport the destination is some other host. A message is passed
1220 to a specific transport as a result of successful routing. If a message has
1221 several recipients, it may be passed to a number of different transports.
1223 .cindex "preconditions" "definition of"
1224 An address is processed by passing it to each configured router instance in
1225 turn, subject to certain preconditions, until a router accepts the address or
1226 specifies that it should be bounced. We will describe this process in more
1227 detail shortly. First, as a simple example, we consider how each recipient
1228 address in a message is processed in a small configuration of three routers.
1230 To make this a more concrete example, it is described in terms of some actual
1231 routers, but remember, this is only an example. You can configure Exim's
1232 routers in many different ways, and there may be any number of routers in a
1233 configuration.
1235 The first router that is specified in a configuration is often one that handles
1236 addresses in domains that are not recognized specifically by the local host.
1237 Typically these are addresses for arbitrary domains on the Internet. A precondition
1238 is set up which looks for the special domains known to the host (for example,
1239 its own domain name), and the router is run for addresses that do &'not'&
1240 match. Typically, this is a router that looks up domains in the DNS in order to
1241 find the hosts to which this address routes. If it succeeds, the address is
1242 assigned to a suitable SMTP transport; if it does not succeed, the router is
1243 configured to fail the address.
1245 The second router is reached only when the domain is recognized as one that
1246 &"belongs"& to the local host. This router does redirection &-- also known as
1247 aliasing and forwarding. When it generates one or more new addresses from the
1248 original, each of them is routed independently from the start. Otherwise, the
1249 router may cause an address to fail, or it may simply decline to handle the
1250 address, in which case the address is passed to the next router.
1252 The final router in many configurations is one that checks to see if the
1253 address belongs to a local mailbox. The precondition may involve a check to
1254 see if the local part is the name of a login account, or it may look up the
1255 local part in a file or a database. If its preconditions are not met, or if
1256 the router declines, we have reached the end of the routers. When this happens,
1257 the address is bounced.
1261 .section "Processing an address for verification" "SECID16"
1262 .cindex "router" "for verification"
1263 .cindex "verifying address" "overview"
1264 As well as being used to decide how to deliver to an address, Exim's routers
1265 are also used for &'address verification'&. Verification can be requested as
1266 one of the checks to be performed in an ACL for incoming messages, on both
1267 sender and recipient addresses, and it can be tested using the &%-bv%& and
1268 &%-bvs%& command line options.
1270 When an address is being verified, the routers are run in &"verify mode"&. This
1271 does not affect the way the routers work, but it is a state that can be
1272 detected. By this means, a router can be skipped or made to behave differently
1273 when verifying. A common example is a configuration in which the first router
1274 sends all messages to a message-scanning program unless they have been
1275 previously scanned. Thus, the first router accepts all addresses without any
1276 checking, making it useless for verifying. Normally, the &%no_verify%& option
1277 would be set for such a router, causing it to be skipped in verify mode.
1282 .section "Running an individual router" "SECTrunindrou"
1283 .cindex "router" "running details"
1284 .cindex "preconditions" "checking"
1285 .cindex "router" "result of running"
1286 As explained in the example above, a number of preconditions are checked before
1287 running a router. If any are not met, the router is skipped, and the address is
1288 passed to the next router. When all the preconditions on a router &'are'& met,
1289 the router is run. What happens next depends on the outcome, which is one of
1290 the following:
1292 .ilist
1293 &'accept'&: The router accepts the address, and either assigns it to a
1294 transport or generates one or more &"child"& addresses. Processing the
1295 original address ceases
1296 .oindex "&%unseen%&"
1297 unless the &%unseen%& option is set on the router. This option
1298 can be used to set up multiple deliveries with different routing (for example,
1299 for keeping archive copies of messages). When &%unseen%& is set, the address is
1300 passed to the next router. Normally, however, an &'accept'& return marks the
1301 end of routing.
1303 Any child addresses generated by the router are processed independently,
1304 starting with the first router by default. It is possible to change this by
1305 setting the &%redirect_router%& option to specify which router to start at for
1306 child addresses. Unlike &%pass_router%& (see below) the router specified by
1307 &%redirect_router%& may be anywhere in the router configuration.
1308 .next
1309 &'pass'&: The router recognizes the address, but cannot handle it itself. It
1310 requests that the address be passed to another router. By default, the address
1311 is passed to the next router, but this can be changed by setting the
1312 &%pass_router%& option. However, (unlike &%redirect_router%&) the named router
1313 must be below the current router (to avoid loops).
1314 .next
1315 &'decline'&: The router declines to accept the address because it does not
1316 recognize it at all. By default, the address is passed to the next router, but
1317 this can be prevented by setting the &%no_more%& option. When &%no_more%& is
1318 set, all the remaining routers are skipped. In effect, &%no_more%& converts
1319 &'decline'& into &'fail'&.
1320 .next
1321 &'fail'&: The router determines that the address should fail, and queues it for
1322 the generation of a bounce message. There is no further processing of the
1323 original address unless &%unseen%& is set on the router.
1324 .next
1325 &'defer'&: The router cannot handle the address at the present time. (A
1326 database may be offline, or a DNS lookup may have timed out.) No further
1327 processing of the address happens in this delivery attempt. It is tried again
1328 next time the message is considered for delivery.
1329 .next
1330 &'error'&: There is some error in the router (for example, a syntax error in
1331 its configuration). The action is as for defer.
1332 .endlist
1334 If an address reaches the end of the routers without having been accepted by
1335 any of them, it is bounced as unrouteable. The default error message in this
1336 situation is &"unrouteable address"&, but you can set your own message by
1337 making use of the &%cannot_route_message%& option. This can be set for any
1338 router; the value from the last router that &"saw"& the address is used.
1340 Sometimes while routing you want to fail a delivery when some conditions are
1341 met but others are not, instead of passing the address on for further routing.
1342 You can do this by having a second router that explicitly fails the delivery
1343 when the relevant conditions are met. The &(redirect)& router has a &"fail"&
1344 facility for this purpose.
1347 .section "Duplicate addresses" "SECID17"
1348 .cindex "case of local parts"
1349 .cindex "address duplicate, discarding"
1350 .cindex "duplicate addresses"
1351 Once routing is complete, Exim scans the addresses that are assigned to local
1352 and remote transports and discards any duplicates that it finds. During this
1353 check, local parts are treated case-sensitively. This happens only when
1354 actually delivering a message; when testing routers with &%-bt%&, all the
1355 routed addresses are shown.
1359 .section "Router preconditions" "SECTrouprecon"
1360 .cindex "router" "preconditions, order of processing"
1361 .cindex "preconditions" "order of processing"
1362 The preconditions that are tested for each router are listed below, in the
1363 order in which they are tested. The individual configuration options are
1364 described in more detail in chapter &<<CHAProutergeneric>>&.
1366 .ilist
1367 .cindex affix "router precondition"
1368 The &%local_part_prefix%& and &%local_part_suffix%& options can specify that
1369 the local parts handled by the router may or must have certain prefixes and/or
1370 suffixes. If a mandatory affix (prefix or suffix) is not present, the router is
1371 skipped. These conditions are tested first. When an affix is present, it is
1372 removed from the local part before further processing, including the evaluation
1373 of any other conditions.
1374 .next
1375 Routers can be designated for use only when not verifying an address, that is,
1376 only when routing it for delivery (or testing its delivery routing). If the
1377 &%verify%& option is set false, the router is skipped when Exim is verifying an
1378 address.
1379 Setting the &%verify%& option actually sets two options, &%verify_sender%& and
1380 &%verify_recipient%&, which independently control the use of the router for
1381 sender and recipient verification. You can set these options directly if
1382 you want a router to be used for only one type of verification.
1383 Note that cutthrough delivery is classed as a recipient verification for this purpose.
1384 .next
1385 If the &%address_test%& option is set false, the router is skipped when Exim is
1386 run with the &%-bt%& option to test an address routing. This can be helpful
1387 when the first router sends all new messages to a scanner of some sort; it
1388 makes it possible to use &%-bt%& to test subsequent delivery routing without
1389 having to simulate the effect of the scanner.
1390 .next
1391 Routers can be designated for use only when verifying an address, as
1392 opposed to routing it for delivery. The &%verify_only%& option controls this.
1393 Again, cutthrough delivery counts as a verification.
1394 .next
1395 Individual routers can be explicitly skipped when running the routers to
1396 check an address given in the SMTP EXPN command (see the &%expn%& option).
1397 .next
1398 If the &%domains%& option is set, the domain of the address must be in the set
1399 of domains that it defines.
1400 .next
1401 .vindex "&$local_part_prefix$&"
1402 .vindex "&$local_part_prefix_v$&"
1403 .vindex "&$local_part$&"
1404 .vindex "&$local_part_suffix$&"
1405 .vindex "&$local_part_suffix_v$&"
1406 .cindex affix "router precondition"
1407 If the &%local_parts%& option is set, the local part of the address must be in
1408 the set of local parts that it defines. If &%local_part_prefix%& or
1409 &%local_part_suffix%& is in use, the prefix or suffix is removed from the local
1410 part before this check. If you want to do precondition tests on local parts
1411 that include affixes, you can do so by using a &%condition%& option (see below)
1412 .new
1413 that uses the variables &$local_part$&, &$local_part_prefix$&,
1414 &$local_part_prefix_v$&, &$local_part_suffix$&
1415 and &$local_part_suffix_v$& as necessary.
1416 .wen
1417 .next
1418 .vindex "&$local_user_uid$&"
1419 .vindex "&$local_user_gid$&"
1420 .vindex "&$home$&"
1421 If the &%check_local_user%& option is set, the local part must be the name of
1422 an account on the local host. If this check succeeds, the uid and gid of the
1423 local user are placed in &$local_user_uid$& and &$local_user_gid$& and the
1424 user's home directory is placed in &$home$&; these values can be used in the
1425 remaining preconditions.
1426 .next
1427 If the &%router_home_directory%& option is set, it is expanded at this point,
1428 because it overrides the value of &$home$&. If this expansion were left till
1429 later, the value of &$home$& as set by &%check_local_user%& would be used in
1430 subsequent tests. Having two different values of &$home$& in the same router
1431 could lead to confusion.
1432 .next
1433 If the &%senders%& option is set, the envelope sender address must be in the
1434 set of addresses that it defines.
1435 .next
1436 If the &%require_files%& option is set, the existence or non-existence of
1437 specified files is tested.
1438 .next
1439 .cindex "customizing" "precondition"
1440 If the &%condition%& option is set, it is evaluated and tested. This option
1441 uses an expanded string to allow you to set up your own custom preconditions.
1442 Expanded strings are described in chapter &<<CHAPexpand>>&.
1443 .endlist
1446 Note that &%require_files%& comes near the end of the list, so you cannot use
1447 it to check for the existence of a file in which to lookup up a domain, local
1448 part, or sender. However, as these options are all expanded, you can use the
1449 &%exists%& expansion condition to make such tests within each condition. The
1450 &%require_files%& option is intended for checking files that the router may be
1451 going to use internally, or which are needed by a specific transport (for
1452 example, &_.procmailrc_&).
1456 .section "Delivery in detail" "SECID18"
1457 .cindex "delivery" "in detail"
1458 When a message is to be delivered, the sequence of events is as follows:
1460 .ilist
1461 If a system-wide filter file is specified, the message is passed to it. The
1462 filter may add recipients to the message, replace the recipients, discard the
1463 message, cause a new message to be generated, or cause the message delivery to
1464 fail. The format of the system filter file is the same as for Exim user filter
1465 files, described in the separate document entitled &'Exim's interfaces to mail
1466 filtering'&.
1467 .cindex "Sieve filter" "not available for system filter"
1468 (&*Note*&: Sieve cannot be used for system filter files.)
1470 Some additional features are available in system filters &-- see chapter
1471 &<<CHAPsystemfilter>>& for details. Note that a message is passed to the system
1472 filter only once per delivery attempt, however many recipients it has. However,
1473 if there are several delivery attempts because one or more addresses could not
1474 be immediately delivered, the system filter is run each time. The filter
1475 condition &%first_delivery%& can be used to detect the first run of the system
1476 filter.
1477 .next
1478 Each recipient address is offered to each configured router, in turn, subject to
1479 its preconditions, until one is able to handle it. If no router can handle the
1480 address, that is, if they all decline, the address is failed. Because routers
1481 can be targeted at particular domains, several locally handled domains can be
1482 processed entirely independently of each other.
1483 .next
1484 .cindex "routing" "loops in"
1485 .cindex "loop" "while routing"
1486 A router that accepts an address may assign it to a local or a remote
1487 transport. However, the transport is not run at this time. Instead, the address
1488 is placed on a list for the particular transport, which will be run later.
1489 Alternatively, the router may generate one or more new addresses (typically
1490 from alias, forward, or filter files). New addresses are fed back into this
1491 process from the top, but in order to avoid loops, a router ignores any address
1492 which has an identically-named ancestor that was processed by itself.
1493 .next
1494 When all the routing has been done, addresses that have been successfully
1495 handled are passed to their assigned transports. When local transports are
1496 doing real local deliveries, they handle only one address at a time, but if a
1497 local transport is being used as a pseudo-remote transport (for example, to
1498 collect batched SMTP messages for transmission by some other means) multiple
1499 addresses can be handled. Remote transports can always handle more than one
1500 address at a time, but can be configured not to do so, or to restrict multiple
1501 addresses to the same domain.
1502 .next
1503 Each local delivery to a file or a pipe runs in a separate process under a
1504 non-privileged uid, and these deliveries are run one at a time. Remote
1505 deliveries also run in separate processes, normally under a uid that is private
1506 to Exim (&"the Exim user"&), but in this case, several remote deliveries can be
1507 run in parallel. The maximum number of simultaneous remote deliveries for any
1508 one message is set by the &%remote_max_parallel%& option.
1509 The order in which deliveries are done is not defined, except that all local
1510 deliveries happen before any remote deliveries.
1511 .next
1512 .cindex "queue runner"
1513 When it encounters a local delivery during a queue run, Exim checks its retry
1514 database to see if there has been a previous temporary delivery failure for the
1515 address before running the local transport. If there was a previous failure,
1516 Exim does not attempt a new delivery until the retry time for the address is
1517 reached. However, this happens only for delivery attempts that are part of a
1518 queue run. Local deliveries are always attempted when delivery immediately
1519 follows message reception, even if retry times are set for them. This makes for
1520 better behaviour if one particular message is causing problems (for example,
1521 causing quota overflow, or provoking an error in a filter file).
1522 .next
1523 .cindex "delivery" "retry in remote transports"
1524 Remote transports do their own retry handling, since an address may be
1525 deliverable to one of a number of hosts, each of which may have a different
1526 retry time. If there have been previous temporary failures and no host has
1527 reached its retry time, no delivery is attempted, whether in a queue run or
1528 not. See chapter &<<CHAPretry>>& for details of retry strategies.
1529 .next
1530 If there were any permanent errors, a bounce message is returned to an
1531 appropriate address (the sender in the common case), with details of the error
1532 for each failing address. Exim can be configured to send copies of bounce
1533 messages to other addresses.
1534 .next
1535 .cindex "delivery" "deferral"
1536 If one or more addresses suffered a temporary failure, the message is left on
1537 the queue, to be tried again later. Delivery of these addresses is said to be
1538 &'deferred'&.
1539 .next
1540 When all the recipient addresses have either been delivered or bounced,
1541 handling of the message is complete. The spool files and message log are
1542 deleted, though the message log can optionally be preserved if required.
1543 .endlist
1548 .section "Retry mechanism" "SECID19"
1549 .cindex "delivery" "retry mechanism"
1550 .cindex "retry" "description of mechanism"
1551 .cindex "queue runner"
1552 Exim's mechanism for retrying messages that fail to get delivered at the first
1553 attempt is the queue runner process. You must either run an Exim daemon that
1554 uses the &%-q%& option with a time interval to start queue runners at regular
1555 intervals or use some other means (such as &'cron'&) to start them. If you do
1556 not arrange for queue runners to be run, messages that fail temporarily at the
1557 first attempt will remain in your queue forever. A queue runner process works
1558 its way through the queue, one message at a time, trying each delivery that has
1559 passed its retry time.
1560 You can run several queue runners at once.
1562 Exim uses a set of configured rules to determine when next to retry the failing
1563 address (see chapter &<<CHAPretry>>&). These rules also specify when Exim
1564 should give up trying to deliver to the address, at which point it generates a
1565 bounce message. If no retry rules are set for a particular host, address, and
1566 error combination, no retries are attempted, and temporary errors are treated
1567 as permanent.
1571 .section "Temporary delivery failure" "SECID20"
1572 .cindex "delivery" "temporary failure"
1573 There are many reasons why a message may not be immediately deliverable to a
1574 particular address. Failure to connect to a remote machine (because it, or the
1575 connection to it, is down) is one of the most common. Temporary failures may be
1576 detected during routing as well as during the transport stage of delivery.
1577 Local deliveries may be delayed if NFS files are unavailable, or if a mailbox
1578 is on a file system where the user is over quota. Exim can be configured to
1579 impose its own quotas on local mailboxes; where system quotas are set they will
1580 also apply.
1582 If a host is unreachable for a period of time, a number of messages may be
1583 waiting for it by the time it recovers, and sending them in a single SMTP
1584 connection is clearly beneficial. Whenever a delivery to a remote host is
1585 deferred,
1586 .cindex "hints database" "deferred deliveries"
1587 Exim makes a note in its hints database, and whenever a successful
1588 SMTP delivery has happened, it looks to see if any other messages are waiting
1589 for the same host. If any are found, they are sent over the same SMTP
1590 connection, subject to a configuration limit as to the maximum number in any
1591 one connection.
1595 .section "Permanent delivery failure" "SECID21"
1596 .cindex "delivery" "permanent failure"
1597 .cindex "bounce message" "when generated"
1598 When a message cannot be delivered to some or all of its intended recipients, a
1599 bounce message is generated. Temporary delivery failures turn into permanent
1600 errors when their timeout expires. All the addresses that fail in a given
1601 delivery attempt are listed in a single message. If the original message has
1602 many recipients, it is possible for some addresses to fail in one delivery
1603 attempt and others to fail subsequently, giving rise to more than one bounce
1604 message. The wording of bounce messages can be customized by the administrator.
1605 See chapter &<<CHAPemsgcust>>& for details.
1607 .cindex "&'X-Failed-Recipients:'& header line"
1608 Bounce messages contain an &'X-Failed-Recipients:'& header line that lists the
1609 failed addresses, for the benefit of programs that try to analyse such messages
1610 automatically.
1612 .cindex "bounce message" "recipient of"
1613 A bounce message is normally sent to the sender of the original message, as
1614 obtained from the message's envelope. For incoming SMTP messages, this is the
1615 address given in the MAIL command. However, when an address is expanded via a
1616 forward or alias file, an alternative address can be specified for delivery
1617 failures of the generated addresses. For a mailing list expansion (see section
1618 &<<SECTmailinglists>>&) it is common to direct bounce messages to the manager
1619 of the list.
1623 .section "Failures to deliver bounce messages" "SECID22"
1624 .cindex "bounce message" "failure to deliver"
1625 If a bounce message (either locally generated or received from a remote host)
1626 itself suffers a permanent delivery failure, the message is left in the queue,
1627 but it is frozen, awaiting the attention of an administrator. There are options
1628 that can be used to make Exim discard such failed messages, or to keep them
1629 for only a short time (see &%timeout_frozen_after%& and
1630 &%ignore_bounce_errors_after%&).
1636 . ////////////////////////////////////////////////////////////////////////////
1637 . ////////////////////////////////////////////////////////////////////////////
1639 .chapter "Building and installing Exim" "CHID3"
1640 .scindex IIDbuex "building Exim"
1642 .section "Unpacking" "SECID23"
1643 Exim is distributed as a gzipped or bzipped tar file which, when unpacked,
1644 creates a directory with the name of the current release (for example,
1645 &_exim-&version()_&) into which the following files are placed:
1647 .table2 140pt
1648 .irow &_ACKNOWLEDGMENTS_& "contains some acknowledgments"
1649 .irow &_CHANGES_& "contains a reference to where changes are &&&
1650 documented"
1651 .irow &_LICENCE_& "the GNU General Public Licence"
1652 .irow &_Makefile_& "top-level make file"
1653 .irow &_NOTICE_& "conditions for the use of Exim"
1654 .irow &_README_& "list of files, directories and simple build &&&
1655 instructions"
1656 .endtable
1658 Other files whose names begin with &_README_& may also be present. The
1659 following subdirectories are created:
1661 .table2 140pt
1662 .irow &_Local_& "an empty directory for local configuration files"
1663 .irow &_OS_& "OS-specific files"
1664 .irow &_doc_& "documentation files"
1665 .irow &_exim_monitor_& "source files for the Exim monitor"
1666 .irow &_scripts_& "scripts used in the build process"
1667 .irow &_src_& "remaining source files"
1668 .irow &_util_& "independent utilities"
1669 .endtable
1671 The main utility programs are contained in the &_src_& directory and are built
1672 with the Exim binary. The &_util_& directory contains a few optional scripts
1673 that may be useful to some sites.
1676 .section "Multiple machine architectures and operating systems" "SECID24"
1677 .cindex "building Exim" "multiple OS/architectures"
1678 The building process for Exim is arranged to make it easy to build binaries for
1679 a number of different architectures and operating systems from the same set of
1680 source files. Compilation does not take place in the &_src_& directory.
1681 Instead, a &'build directory'& is created for each architecture and operating
1682 system.
1683 .cindex "symbolic link" "to build directory"
1684 Symbolic links to the sources are installed in this directory, which is where
1685 the actual building takes place. In most cases, Exim can discover the machine
1686 architecture and operating system for itself, but the defaults can be
1687 overridden if necessary.
1688 .cindex compiler requirements
1689 .cindex compiler version
1690 A C99-capable compiler will be required for the build.
1693 .section "PCRE library" "SECTpcre"
1694 .cindex "PCRE library"
1695 Exim no longer has an embedded PCRE library as the vast majority of
1696 modern systems include PCRE as a system library, although you may need to
1697 install the PCRE package or the PCRE development package for your operating
1698 system. If your system has a normal PCRE installation the Exim build
1699 process will need no further configuration. If the library or the
1700 headers are in an unusual location you will need to either set the PCRE_LIBS
1701 and INCLUDE directives appropriately,
1702 or set PCRE_CONFIG=yes to use the installed &(pcre-config)& command.
1703 If your operating system has no
1704 PCRE support then you will need to obtain and build the current PCRE
1705 from &url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/).
1706 More information on PCRE is available at &url(https://www.pcre.org/).
1708 .section "DBM libraries" "SECTdb"
1709 .cindex "DBM libraries" "discussion of"
1710 .cindex "hints database" "DBM files used for"
1711 Even if you do not use any DBM files in your configuration, Exim still needs a
1712 DBM library in order to operate, because it uses indexed files for its hints
1713 databases. Unfortunately, there are a number of DBM libraries in existence, and
1714 different operating systems often have different ones installed.
1716 .cindex "Solaris" "DBM library for"
1717 .cindex "IRIX, DBM library for"
1718 .cindex "BSD, DBM library for"
1719 .cindex "Linux, DBM library for"
1720 If you are using Solaris, IRIX, one of the modern BSD systems, or a modern
1721 Linux distribution, the DBM configuration should happen automatically, and you
1722 may be able to ignore this section. Otherwise, you may have to learn more than
1723 you would like about DBM libraries from what follows.
1725 .cindex "&'ndbm'& DBM library"
1726 Licensed versions of Unix normally contain a library of DBM functions operating
1727 via the &'ndbm'& interface, and this is what Exim expects by default. Free
1728 versions of Unix seem to vary in what they contain as standard. In particular,
1729 some early versions of Linux have no default DBM library, and different
1730 distributors have chosen to bundle different libraries with their packaged
1731 versions. However, the more recent releases seem to have standardized on the
1732 Berkeley DB library.
1734 Different DBM libraries have different conventions for naming the files they
1735 use. When a program opens a file called &_dbmfile_&, there are several
1736 possibilities:
1738 .olist
1739 A traditional &'ndbm'& implementation, such as that supplied as part of
1740 Solaris, operates on two files called &_dbmfile.dir_& and &_dbmfile.pag_&.
1741 .next
1742 .cindex "&'gdbm'& DBM library"
1743 The GNU library, &'gdbm'&, operates on a single file. If used via its &'ndbm'&
1744 compatibility interface it makes two different hard links to it with names
1745 &_dbmfile.dir_& and &_dbmfile.pag_&, but if used via its native interface, the
1746 filename is used unmodified.
1747 .next
1748 .cindex "Berkeley DB library"
1749 The Berkeley DB package, if called via its &'ndbm'& compatibility interface,
1750 operates on a single file called &_dbmfile.db_&, but otherwise looks to the
1751 programmer exactly the same as the traditional &'ndbm'& implementation.
1752 .next
1753 If the Berkeley package is used in its native mode, it operates on a single
1754 file called &_dbmfile_&; the programmer's interface is somewhat different to
1755 the traditional &'ndbm'& interface.
1756 .next
1757 To complicate things further, there are several very different versions of the
1758 Berkeley DB package. Version 1.85 was stable for a very long time, releases
1759 2.&'x'& and 3.&'x'& were current for a while, but the latest versions when Exim last revamped support were numbered 4.&'x'&.
1760 Maintenance of some of the earlier releases has ceased. All versions of
1761 Berkeley DB could be obtained from
1762 &url(http://www.sleepycat.com/), which is now a redirect to their new owner's
1763 page with far newer versions listed.
1764 It is probably wise to plan to move your storage configurations away from
1765 Berkeley DB format, as today there are smaller and simpler alternatives more
1766 suited to Exim's usage model.
1767 .next
1768 .cindex "&'tdb'& DBM library"
1769 Yet another DBM library, called &'tdb'&, is available from
1770 &url(https://sourceforge.net/projects/tdb/files/). It has its own interface, and also
1771 operates on a single file.
1772 .endlist
1774 .cindex "USE_DB"
1775 .cindex "DBM libraries" "configuration for building"
1776 Exim and its utilities can be compiled to use any of these interfaces. In order
1777 to use any version of the Berkeley DB package in native mode, you must set
1778 USE_DB in an appropriate configuration file (typically
1779 &_Local/Makefile_&). For example:
1780 .code
1781 USE_DB=yes
1782 .endd
1783 Similarly, for gdbm you set USE_GDBM, and for tdb you set USE_TDB. An
1784 error is diagnosed if you set more than one of these.
1786 At the lowest level, the build-time configuration sets none of these options,
1787 thereby assuming an interface of type (1). However, some operating system
1788 configuration files (for example, those for the BSD operating systems and
1789 Linux) assume type (4) by setting USE_DB as their default, and the
1790 configuration files for Cygwin set USE_GDBM. Anything you set in
1791 &_Local/Makefile_&, however, overrides these system defaults.
1793 As well as setting USE_DB, USE_GDBM, or USE_TDB, it may also be
1794 necessary to set DBMLIB, to cause inclusion of the appropriate library, as
1795 in one of these lines:
1796 .code
1797 DBMLIB = -ldb
1798 DBMLIB = -ltdb
1799 .endd
1800 Settings like that will work if the DBM library is installed in the standard
1801 place. Sometimes it is not, and the library's header file may also not be in
1802 the default path. You may need to set INCLUDE to specify where the header
1803 file is, and to specify the path to the library more fully in DBMLIB, as in
1804 this example:
1805 .code
1806 INCLUDE=-I/usr/local/include/db-4.1
1807 DBMLIB=/usr/local/lib/db-4.1/libdb.a
1808 .endd
1809 There is further detailed discussion about the various DBM libraries in the
1810 file &_doc/dbm.discuss.txt_& in the Exim distribution.
1814 .section "Pre-building configuration" "SECID25"
1815 .cindex "building Exim" "pre-building configuration"
1816 .cindex "configuration for building Exim"
1817 .cindex "&_Local/Makefile_&"
1818 .cindex "&_src/EDITME_&"
1819 Before building Exim, a local configuration file that specifies options
1820 independent of any operating system has to be created with the name
1821 &_Local/Makefile_&. A template for this file is supplied as the file
1822 &_src/EDITME_&, and it contains full descriptions of all the option settings
1823 therein. These descriptions are therefore not repeated here. If you are
1824 building Exim for the first time, the simplest thing to do is to copy
1825 &_src/EDITME_& to &_Local/Makefile_&, then read it and edit it appropriately.
1827 There are three settings that you must supply, because Exim will not build
1828 without them. They are the location of the runtime configuration file
1829 (CONFIGURE_FILE), the directory in which Exim binaries will be installed
1830 (BIN_DIRECTORY), and the identity of the Exim user (EXIM_USER and
1831 maybe EXIM_GROUP as well). The value of CONFIGURE_FILE can in fact be
1832 a colon-separated list of filenames; Exim uses the first of them that exists.
1834 There are a few other parameters that can be specified either at build time or
1835 at runtime, to enable the same binary to be used on a number of different
1836 machines. However, if the locations of Exim's spool directory and log file
1837 directory (if not within the spool directory) are fixed, it is recommended that
1838 you specify them in &_Local/Makefile_& instead of at runtime, so that errors
1839 detected early in Exim's execution (such as a malformed configuration file) can
1840 be logged.
1842 .cindex "content scanning" "specifying at build time"
1843 Exim's interfaces for calling virus and spam scanning software directly from
1844 access control lists are not compiled by default. If you want to include these
1845 facilities, you need to set
1846 .code
1848 .endd
1849 in your &_Local/Makefile_&. For details of the facilities themselves, see
1850 chapter &<<CHAPexiscan>>&.
1853 .cindex "&_Local/eximon.conf_&"
1854 .cindex "&_exim_monitor/EDITME_&"
1855 If you are going to build the Exim monitor, a similar configuration process is
1856 required. The file &_exim_monitor/EDITME_& must be edited appropriately for
1857 your installation and saved under the name &_Local/eximon.conf_&. If you are
1858 happy with the default settings described in &_exim_monitor/EDITME_&,
1859 &_Local/eximon.conf_& can be empty, but it must exist.
1861 This is all the configuration that is needed in straightforward cases for known
1862 operating systems. However, the building process is set up so that it is easy
1863 to override options that are set by default or by operating-system-specific
1864 configuration files, for example, to change the C compiler, which
1865 defaults to &%gcc%&. See section &<<SECToverride>>& below for details of how to
1866 do this.
1870 .section "Support for iconv()" "SECID26"
1871 .cindex "&[iconv()]& support"
1872 .cindex "RFC 2047"
1873 The contents of header lines in messages may be encoded according to the rules
1874 described RFC 2047. This makes it possible to transmit characters that are not
1875 in the ASCII character set, and to label them as being in a particular
1876 character set. When Exim is inspecting header lines by means of the &%$h_%&
1877 mechanism, it decodes them, and translates them into a specified character set
1878 (default is set at build time). The translation is possible only if the operating system
1879 supports the &[iconv()]& function.
1881 However, some of the operating systems that supply &[iconv()]& do not support
1882 very many conversions. The GNU &%libiconv%& library (available from
1883 &url(https://www.gnu.org/software/libiconv/)) can be installed on such
1884 systems to remedy this deficiency, as well as on systems that do not supply
1885 &[iconv()]& at all. After installing &%libiconv%&, you should add
1886 .code
1887 HAVE_ICONV=yes
1888 .endd
1889 to your &_Local/Makefile_& and rebuild Exim.
1893 .section "Including TLS/SSL encryption support" "SECTinctlsssl"
1894 .cindex "TLS" "including support for TLS"
1895 .cindex "encryption" "including support for"
1896 .cindex "OpenSSL" "building Exim with"
1897 .cindex "GnuTLS" "building Exim with"
1898 Exim is usually built to support encrypted SMTP connections, using the STARTTLS
1899 command as per RFC 2487. It can also support clients that expect to
1900 start a TLS session immediately on connection to a non-standard port (see the
1901 &%tls_on_connect_ports%& runtime option and the &%-tls-on-connect%& command
1902 line option).
1904 If you want to build Exim with TLS support, you must first install either the
1905 OpenSSL or GnuTLS library. There is no cryptographic code in Exim itself for
1906 implementing SSL.
1908 If you do not want TLS support you should set
1909 .code
1910 DISABLE_TLS=yes
1911 .endd
1912 in &_Local/Makefile_&.
1914 If OpenSSL is installed, you should set
1915 .code
1916 USE_OPENSL=yes
1917 TLS_LIBS=-lssl -lcrypto
1918 .endd
1919 in &_Local/Makefile_&. You may also need to specify the locations of the
1920 OpenSSL library and include files. For example:
1921 .code
1922 USE_OPENSSL=yes
1923 TLS_LIBS=-L/usr/local/openssl/lib -lssl -lcrypto
1924 TLS_INCLUDE=-I/usr/local/openssl/include/
1925 .endd
1926 .cindex "pkg-config" "OpenSSL"
1927 If you have &'pkg-config'& available, then instead you can just use:
1928 .code
1929 USE_OPENSSL=yes
1930 USE_OPENSSL_PC=openssl
1931 .endd
1932 .cindex "USE_GNUTLS"
1933 If GnuTLS is installed, you should set
1934 .code
1935 USE_GNUTLS=yes
1936 TLS_LIBS=-lgnutls -ltasn1 -lgcrypt
1937 .endd
1938 in &_Local/Makefile_&, and again you may need to specify the locations of the
1939 library and include files. For example:
1940 .code
1941 USE_GNUTLS=yes
1942 TLS_LIBS=-L/usr/gnu/lib -lgnutls -ltasn1 -lgcrypt
1943 TLS_INCLUDE=-I/usr/gnu/include
1944 .endd
1945 .cindex "pkg-config" "GnuTLS"
1946 If you have &'pkg-config'& available, then instead you can just use:
1947 .code
1948 USE_GNUTLS=yes
1949 USE_GNUTLS_PC=gnutls
1950 .endd
1952 You do not need to set TLS_INCLUDE if the relevant directory is already
1953 specified in INCLUDE. Details of how to configure Exim to make use of TLS are
1954 given in chapter &<<CHAPTLS>>&.
1959 .section "Use of tcpwrappers" "SECID27"
1961 .cindex "tcpwrappers, building Exim to support"
1962 .cindex "USE_TCP_WRAPPERS"
1964 .cindex "tcp_wrappers_daemon_name"
1965 Exim can be linked with the &'tcpwrappers'& library in order to check incoming
1966 SMTP calls using the &'tcpwrappers'& control files. This may be a convenient
1967 alternative to Exim's own checking facilities for installations that are
1968 already making use of &'tcpwrappers'& for other purposes. To do this, you
1969 should set USE_TCP_WRAPPERS in &_Local/Makefile_&, arrange for the file
1970 &_tcpd.h_& to be available at compile time, and also ensure that the library
1971 &_libwrap.a_& is available at link time, typically by including &%-lwrap%& in
1972 EXTRALIBS_EXIM. For example, if &'tcpwrappers'& is installed in &_/usr/local_&,
1973 you might have
1974 .code
1976 CFLAGS=-O -I/usr/local/include
1977 EXTRALIBS_EXIM=-L/usr/local/lib -lwrap
1978 .endd
1979 in &_Local/Makefile_&. The daemon name to use in the &'tcpwrappers'& control
1980 files is &"exim"&. For example, the line
1981 .code
1982 exim : LOCAL 192.168.1. .friendly.domain.example
1983 .endd
1984 in your &_/etc/hosts.allow_& file allows connections from the local host, from
1985 the subnet, and from all hosts in &'friendly.domain.example'&.
1986 All other connections are denied. The daemon name used by &'tcpwrappers'&
1987 can be changed at build time by setting TCP_WRAPPERS_DAEMON_NAME in
1988 &_Local/Makefile_&, or by setting tcp_wrappers_daemon_name in the
1989 configure file. Consult the &'tcpwrappers'& documentation for
1990 further details.
1993 .section "Including support for IPv6" "SECID28"
1994 .cindex "IPv6" "including support for"
1995 Exim contains code for use on systems that have IPv6 support. Setting
1996 &`HAVE_IPV6=YES`& in &_Local/Makefile_& causes the IPv6 code to be included;
1997 it may also be necessary to set IPV6_INCLUDE and IPV6_LIBS on systems
1998 where the IPv6 support is not fully integrated into the normal include and
1999 library files.
2001 Two different types of DNS record for handling IPv6 addresses have been
2002 defined. AAAA records (analogous to A records for IPv4) are in use, and are
2003 currently seen as the mainstream. Another record type called A6 was proposed
2004 as better than AAAA because it had more flexibility. However, it was felt to be
2005 over-complex, and its status was reduced to &"experimental"&.
2006 Exim used to
2007 have a compile option for including A6 record support but this has now been
2008 withdrawn.
2012 .section "Dynamically loaded lookup module support" "SECTdynamicmodules"
2013 .cindex "lookup modules"
2014 .cindex "dynamic modules"
2015 .cindex ".so building"
2016 On some platforms, Exim supports not compiling all lookup types directly into
2017 the main binary, instead putting some into external modules which can be loaded
2018 on demand.
2019 This permits packagers to build Exim with support for lookups with extensive
2020 library dependencies without requiring all users to install all of those
2021 dependencies.
2022 Most, but not all, lookup types can be built this way.
2024 Set &`LOOKUP_MODULE_DIR`& to the directory into which the modules will be
2025 installed; Exim will only load modules from that directory, as a security
2026 measure. You will need to set &`CFLAGS_DYNAMIC`& if not already defined
2027 for your OS; see &_OS/Makefile-Linux_& for an example.
2028 Some other requirements for adjusting &`EXTRALIBS`& may also be necessary,
2029 see &_src/EDITME_& for details.
2031 Then, for each module to be loaded dynamically, define the relevant
2032 &`LOOKUP_`&<&'lookup_type'&> flags to have the value "2" instead of "yes".
2033 For example, this will build in lsearch but load sqlite and mysql support
2034 on demand:
2035 .code
2039 .endd
2042 .section "The building process" "SECID29"
2043 .cindex "build directory"
2044 Once &_Local/Makefile_& (and &_Local/eximon.conf_&, if required) have been
2045 created, run &'make'& at the top level. It determines the architecture and
2046 operating system types, and creates a build directory if one does not exist.
2047 For example, on a Sun system running Solaris 8, the directory
2048 &_build-SunOS5-5.8-sparc_& is created.
2049 .cindex "symbolic link" "to source files"
2050 Symbolic links to relevant source files are installed in the build directory.
2052 If this is the first time &'make'& has been run, it calls a script that builds
2053 a make file inside the build directory, using the configuration files from the
2054 &_Local_& directory. The new make file is then passed to another instance of
2055 &'make'&. This does the real work, building a number of utility scripts, and
2056 then compiling and linking the binaries for the Exim monitor (if configured), a
2057 number of utility programs, and finally Exim itself. The command &`make
2058 makefile`& can be used to force a rebuild of the make file in the build
2059 directory, should this ever be necessary.
2061 If you have problems building Exim, check for any comments there may be in the
2062 &_README_& file concerning your operating system, and also take a look at the
2063 FAQ, where some common problems are covered.
2067 .section 'Output from &"make"&' "SECID283"
2068 The output produced by the &'make'& process for compile lines is often very
2069 unreadable, because these lines can be very long. For this reason, the normal
2070 output is suppressed by default, and instead output similar to that which
2071 appears when compiling the 2.6 Linux kernel is generated: just a short line for
2072 each module that is being compiled or linked. However, it is still possible to
2073 get the full output, by calling &'make'& like this:
2074 .code
2075 FULLECHO='' make -e
2076 .endd
2077 The value of FULLECHO defaults to &"@"&, the flag character that suppresses
2078 command reflection in &'make'&. When you ask for the full output, it is
2079 given in addition to the short output.
2083 .section "Overriding build-time options for Exim" "SECToverride"
2084 .cindex "build-time options, overriding"
2085 The main make file that is created at the beginning of the building process
2086 consists of the concatenation of a number of files which set configuration
2087 values, followed by a fixed set of &'make'& instructions. If a value is set
2088 more than once, the last setting overrides any previous ones. This provides a
2089 convenient way of overriding defaults. The files that are concatenated are, in
2090 order:
2091 .display
2092 &_OS/Makefile-Default_&
2093 &_OS/Makefile-_&<&'ostype'&>
2094 &_Local/Makefile_&
2095 &_Local/Makefile-_&<&'ostype'&>
2096 &_Local/Makefile-_&<&'archtype'&>
2097 &_Local/Makefile-_&<&'ostype'&>-<&'archtype'&>
2098 &_OS/Makefile-Base_&
2099 .endd
2100 .cindex "&_Local/Makefile_&"
2101 .cindex "building Exim" "operating system type"
2102 .cindex "building Exim" "architecture type"
2103 where <&'ostype'&> is the operating system type and <&'archtype'&> is the
2104 architecture type. &_Local/Makefile_& is required to exist, and the building
2105 process fails if it is absent. The other three &_Local_& files are optional,
2106 and are often not needed.
2108 The values used for <&'ostype'&> and <&'archtype'&> are obtained from scripts
2109 called &_scripts/os-type_& and &_scripts/arch-type_& respectively. If either of
2110 the environment variables EXIM_OSTYPE or EXIM_ARCHTYPE is set, their
2111 values are used, thereby providing a means of forcing particular settings.
2112 Otherwise, the scripts try to get values from the &%uname%& command. If this
2113 fails, the shell variables OSTYPE and ARCHTYPE are inspected. A number
2114 of &'ad hoc'& transformations are then applied, to produce the standard names
2115 that Exim expects. You can run these scripts directly from the shell in order
2116 to find out what values are being used on your system.
2119 &_OS/Makefile-Default_& contains comments about the variables that are set
2120 therein. Some (but not all) are mentioned below. If there is something that
2121 needs changing, review the contents of this file and the contents of the make
2122 file for your operating system (&_OS/Makefile-<ostype>_&) to see what the
2123 default values are.
2126 .cindex "building Exim" "overriding default settings"
2127 If you need to change any of the values that are set in &_OS/Makefile-Default_&
2128 or in &_OS/Makefile-<ostype>_&, or to add any new definitions, you do not
2129 need to change the original files. Instead, you should make the changes by
2130 putting the new values in an appropriate &_Local_& file. For example,
2131 .cindex "Tru64-Unix build-time settings"
2132 when building Exim in many releases of the Tru64-Unix (formerly Digital UNIX,
2133 formerly DEC-OSF1) operating system, it is necessary to specify that the C
2134 compiler is called &'cc'& rather than &'gcc'&. Also, the compiler must be
2135 called with the option &%-std1%&, to make it recognize some of the features of
2136 Standard C that Exim uses. (Most other compilers recognize Standard C by
2137 default.) To do this, you should create a file called &_Local/Makefile-OSF1_&
2138 containing the lines
2139 .code
2140 CC=cc
2141 CFLAGS=-std1
2142 .endd
2143 If you are compiling for just one operating system, it may be easier to put
2144 these lines directly into &_Local/Makefile_&.
2146 Keeping all your local configuration settings separate from the distributed
2147 files makes it easy to transfer them to new versions of Exim simply by copying
2148 the contents of the &_Local_& directory.
2151 .cindex "NIS lookup type" "including support for"
2152 .cindex "NIS+ lookup type" "including support for"
2153 .cindex "LDAP" "including support for"
2154 .cindex "lookup" "inclusion in binary"
2155 Exim contains support for doing LDAP, NIS, NIS+, and other kinds of file
2156 lookup, but not all systems have these components installed, so the default is
2157 not to include the relevant code in the binary. All the different kinds of file
2158 and database lookup that Exim supports are implemented as separate code modules
2159 which are included only if the relevant compile-time options are set. In the
2160 case of LDAP, NIS, and NIS+, the settings for &_Local/Makefile_& are:
2161 .code
2162 LOOKUP_LDAP=yes
2163 LOOKUP_NIS=yes
2165 .endd
2166 and similar settings apply to the other lookup types. They are all listed in
2167 &_src/EDITME_&. In many cases the relevant include files and interface
2168 libraries need to be installed before compiling Exim.
2169 .cindex "cdb" "including support for"
2170 However, there are some optional lookup types (such as cdb) for which
2171 the code is entirely contained within Exim, and no external include
2172 files or libraries are required. When a lookup type is not included in the
2173 binary, attempts to configure Exim to use it cause runtime configuration
2174 errors.
2176 .cindex "pkg-config" "lookups"
2177 .cindex "pkg-config" "authenticators"
2178 Many systems now use a tool called &'pkg-config'& to encapsulate information
2179 about how to compile against a library; Exim has some initial support for
2180 being able to use pkg-config for lookups and authenticators. For any given
2181 makefile variable which starts &`LOOKUP_`& or &`AUTH_`&, you can add a new
2182 variable with the &`_PC`& suffix in the name and assign as the value the
2183 name of the package to be queried. The results of querying via the
2184 &'pkg-config'& command will be added to the appropriate Makefile variables
2185 with &`+=`& directives, so your version of &'make'& will need to support that
2186 syntax. For instance:
2187 .code
2189 LOOKUP_SQLITE_PC=sqlite3
2190 AUTH_GSASL=yes
2191 AUTH_GSASL_PC=libgsasl
2193 AUTH_HEIMDAL_GSSAPI_PC=heimdal-gssapi
2194 .endd
2196 .cindex "Perl" "including support for"
2197 Exim can be linked with an embedded Perl interpreter, allowing Perl
2198 subroutines to be called during string expansion. To enable this facility,
2199 .code
2200 EXIM_PERL=perl.o
2201 .endd
2202 must be defined in &_Local/Makefile_&. Details of this facility are given in
2203 chapter &<<CHAPperl>>&.
2205 .cindex "X11 libraries, location of"
2206 The location of the X11 libraries is something that varies a lot between
2207 operating systems, and there may be different versions of X11 to cope
2208 with. Exim itself makes no use of X11, but if you are compiling the Exim
2209 monitor, the X11 libraries must be available.
2210 The following three variables are set in &_OS/Makefile-Default_&:
2211 .code
2212 X11=/usr/X11R6
2213 XINCLUDE=-I$(X11)/include
2214 XLFLAGS=-L$(X11)/lib
2215 .endd
2216 These are overridden in some of the operating-system configuration files. For
2217 example, in &_OS/Makefile-SunOS5_& there is
2218 .code
2219 X11=/usr/openwin
2220 XINCLUDE=-I$(X11)/include
2221 XLFLAGS=-L$(X11)/lib -R$(X11)/lib
2222 .endd
2223 If you need to override the default setting for your operating system, place a
2224 definition of all three of these variables into your
2225 &_Local/Makefile-<ostype>_& file.
2227 .cindex "EXTRALIBS"
2228 If you need to add any extra libraries to the link steps, these can be put in a
2229 variable called EXTRALIBS, which appears in all the link commands, but by
2230 default is not defined. In contrast, EXTRALIBS_EXIM is used only on the
2231 command for linking the main Exim binary, and not for any associated utilities.
2233 .cindex "DBM libraries" "configuration for building"
2234 There is also DBMLIB, which appears in the link commands for binaries that
2235 use DBM functions (see also section &<<SECTdb>>&). Finally, there is
2236 EXTRALIBS_EXIMON, which appears only in the link step for the Exim monitor
2237 binary, and which can be used, for example, to include additional X11
2238 libraries.
2240 .cindex "configuration file" "editing"
2241 The make file copes with rebuilding Exim correctly if any of the configuration
2242 files are edited. However, if an optional configuration file is deleted, it is
2243 necessary to touch the associated non-optional file (that is,
2244 &_Local/Makefile_& or &_Local/eximon.conf_&) before rebuilding.
2247 .section "OS-specific header files" "SECID30"
2248 .cindex "&_os.h_&"
2249 .cindex "building Exim" "OS-specific C header files"
2250 The &_OS_& directory contains a number of files with names of the form
2251 &_os.h-<ostype>_&. These are system-specific C header files that should not
2252 normally need to be changed. There is a list of macro settings that are
2253 recognized in the file &_OS/os.configuring_&, which should be consulted if you
2254 are porting Exim to a new operating system.
2258 .section "Overriding build-time options for the monitor" "SECID31"
2259 .cindex "building Eximon"
2260 A similar process is used for overriding things when building the Exim monitor,
2261 where the files that are involved are
2262 .display
2263 &_OS/eximon.conf-Default_&
2264 &_OS/eximon.conf-_&<&'ostype'&>
2265 &_Local/eximon.conf_&
2266 &_Local/eximon.conf-_&<&'ostype'&>
2267 &_Local/eximon.conf-_&<&'archtype'&>
2268 &_Local/eximon.conf-_&<&'ostype'&>-<&'archtype'&>
2269 .endd
2270 .cindex "&_Local/eximon.conf_&"
2271 As with Exim itself, the final three files need not exist, and in this case the
2272 &_OS/eximon.conf-<ostype>_& file is also optional. The default values in
2273 &_OS/eximon.conf-Default_& can be overridden dynamically by setting environment
2274 variables of the same name, preceded by EXIMON_. For example, setting
2275 EXIMON_LOG_DEPTH in the environment overrides the value of
2276 LOG_DEPTH at runtime.
2277 .ecindex IIDbuex
2280 .section "Installing Exim binaries and scripts" "SECID32"
2281 .cindex "installing Exim"
2282 .cindex "BIN_DIRECTORY"
2283 The command &`make install`& runs the &(exim_install)& script with no
2284 arguments. The script copies binaries and utility scripts into the directory
2285 whose name is specified by the BIN_DIRECTORY setting in &_Local/Makefile_&.
2286 .cindex "setuid" "installing Exim with"
2287 The install script copies files only if they are newer than the files they are
2288 going to replace. The Exim binary is required to be owned by root and have the
2289 &'setuid'& bit set, for normal configurations. Therefore, you must run &`make
2290 install`& as root so that it can set up the Exim binary in this way. However, in
2291 some special situations (for example, if a host is doing no local deliveries)
2292 it may be possible to run Exim without making the binary setuid root (see
2293 chapter &<<CHAPsecurity>>& for details).
2295 .cindex "CONFIGURE_FILE"
2296 Exim's runtime configuration file is named by the CONFIGURE_FILE setting
2297 in &_Local/Makefile_&. If this names a single file, and the file does not
2298 exist, the default configuration file &_src/configure.default_& is copied there
2299 by the installation script. If a runtime configuration file already exists, it
2300 is left alone. If CONFIGURE_FILE is a colon-separated list, naming several
2301 alternative files, no default is installed.
2303 .cindex "system aliases file"
2304 .cindex "&_/etc/aliases_&"
2305 One change is made to the default configuration file when it is installed: the
2306 default configuration contains a router that references a system aliases file.
2307 The path to this file is set to the value specified by
2308 SYSTEM_ALIASES_FILE in &_Local/Makefile_& (&_/etc/aliases_& by default).
2309 If the system aliases file does not exist, the installation script creates it,
2310 and outputs a comment to the user.
2312 The created file contains no aliases, but it does contain comments about the
2313 aliases a site should normally have. Mail aliases have traditionally been
2314 kept in &_/etc/aliases_&. However, some operating systems are now using
2315 &_/etc/mail/aliases_&. You should check if yours is one of these, and change
2316 Exim's configuration if necessary.
2318 The default configuration uses the local host's name as the only local domain,
2319 and is set up to do local deliveries into the shared directory &_/var/mail_&,
2320 running as the local user. System aliases and &_.forward_& files in users' home
2321 directories are supported, but no NIS or NIS+ support is configured. Domains
2322 other than the name of the local host are routed using the DNS, with delivery
2323 over SMTP.
2325 It is possible to install Exim for special purposes (such as building a binary
2326 distribution) in a private part of the file system. You can do this by a
2327 command such as
2328 .code
2329 make DESTDIR=/some/directory/ install
2330 .endd
2331 This has the effect of pre-pending the specified directory to all the file
2332 paths, except the name of the system aliases file that appears in the default
2333 configuration. (If a default alias file is created, its name &'is'& modified.)
2334 For backwards compatibility, ROOT is used if DESTDIR is not set,
2335 but this usage is deprecated.
2337 .cindex "installing Exim" "what is not installed"
2338 Running &'make install'& does not copy the Exim 4 conversion script
2339 &'convert4r4'&. You will probably run this only once if you are
2340 upgrading from Exim 3. None of the documentation files in the &_doc_&
2341 directory are copied, except for the info files when you have set
2342 INFO_DIRECTORY, as described in section &<<SECTinsinfdoc>>& below.
2344 For the utility programs, old versions are renamed by adding the suffix &_.O_&
2345 to their names. The Exim binary itself, however, is handled differently. It is
2346 installed under a name that includes the version number and the compile number,
2347 for example, &_exim-&version()-1_&. The script then arranges for a symbolic link
2348 called &_exim_& to point to the binary. If you are updating a previous version
2349 of Exim, the script takes care to ensure that the name &_exim_& is never absent
2350 from the directory (as seen by other processes).
2352 .cindex "installing Exim" "testing the script"
2353 If you want to see what the &'make install'& will do before running it for
2354 real, you can pass the &%-n%& option to the installation script by this
2355 command:
2356 .code
2357 make INSTALL_ARG=-n install
2358 .endd
2359 The contents of the variable INSTALL_ARG are passed to the installation
2360 script. You do not need to be root to run this test. Alternatively, you can run
2361 the installation script directly, but this must be from within the build
2362 directory. For example, from the top-level Exim directory you could use this
2363 command:
2364 .code
2365 (cd build-SunOS5-5.5.1-sparc; ../scripts/exim_install -n)
2366 .endd
2367 .cindex "installing Exim" "install script options"
2368 There are two other options that can be supplied to the installation script.
2370 .ilist
2371 &%-no_chown%& bypasses the call to change the owner of the installed binary
2372 to root, and the call to make it a setuid binary.
2373 .next
2374 &%-no_symlink%& bypasses the setting up of the symbolic link &_exim_& to the
2375 installed binary.
2376 .endlist
2378 INSTALL_ARG can be used to pass these options to the script. For example:
2379 .code
2380 make INSTALL_ARG=-no_symlink install
2381 .endd
2382 The installation script can also be given arguments specifying which files are
2383 to be copied. For example, to install just the Exim binary, and nothing else,
2384 without creating the symbolic link, you could use:
2385 .code
2386 make INSTALL_ARG='-no_symlink exim' install
2387 .endd
2391 .section "Installing info documentation" "SECTinsinfdoc"
2392 .cindex "installing Exim" "&'info'& documentation"
2393 Not all systems use the GNU &'info'& system for documentation, and for this
2394 reason, the Texinfo source of Exim's documentation is not included in the main
2395 distribution. Instead it is available separately from the FTP site (see section
2396 &<<SECTavail>>&).
2398 If you have defined INFO_DIRECTORY in &_Local/Makefile_& and the Texinfo
2399 source of the documentation is found in the source tree, running &`make
2400 install`& automatically builds the info files and installs them.
2404 .section "Setting up the spool directory" "SECID33"
2405 .cindex "spool directory" "creating"
2406 When it starts up, Exim tries to create its spool directory if it does not
2407 exist. The Exim uid and gid are used for the owner and group of the spool
2408 directory. Sub-directories are automatically created in the spool directory as
2409 necessary.
2414 .section "Testing" "SECID34"
2415 .cindex "testing" "installation"
2416 Having installed Exim, you can check that the runtime configuration file is
2417 syntactically valid by running the following command, which assumes that the
2418 Exim binary directory is within your PATH environment variable:
2419 .code
2420 exim -bV
2421 .endd
2422 If there are any errors in the configuration file, Exim outputs error messages.
2423 Otherwise it outputs the version number and build date,
2424 the DBM library that is being used, and information about which drivers and
2425 other optional code modules are included in the binary.
2426 Some simple routing tests can be done by using the address testing option. For
2427 example,
2428 .display
2429 &`exim -bt`& <&'local username'&>
2430 .endd
2431 should verify that it recognizes a local mailbox, and
2432 .display
2433 &`exim -bt`& <&'remote address'&>
2434 .endd
2435 a remote one. Then try getting it to deliver mail, both locally and remotely.
2436 This can be done by passing messages directly to Exim, without going through a
2437 user agent. For example:
2438 .code
2439 exim -v postmaster@your.domain.example
2440 From: user@your.domain.example
2441 To: postmaster@your.domain.example
2442 Subject: Testing Exim
2444 This is a test message.
2445 ^D
2446 .endd
2447 The &%-v%& option causes Exim to output some verification of what it is doing.
2448 In this case you should see copies of three log lines, one for the message's
2449 arrival, one for its delivery, and one containing &"Completed"&.
2451 .cindex "delivery" "problems with"
2452 If you encounter problems, look at Exim's log files (&'mainlog'& and
2453 &'paniclog'&) to see if there is any relevant information there. Another source
2454 of information is running Exim with debugging turned on, by specifying the
2455 &%-d%& option. If a message is stuck on Exim's spool, you can force a delivery
2456 with debugging turned on by a command of the form
2457 .display
2458 &`exim -d -M`& <&'exim-message-id'&>
2459 .endd
2460 You must be root or an &"admin user"& in order to do this. The &%-d%& option
2461 produces rather a lot of output, but you can cut this down to specific areas.
2462 For example, if you use &%-d-all+route%& only the debugging information
2463 relevant to routing is included. (See the &%-d%& option in chapter
2464 &<<CHAPcommandline>>& for more details.)
2466 .cindex '&"sticky"& bit'
2467 .cindex "lock files"
2468 One specific problem that has shown up on some sites is the inability to do
2469 local deliveries into a shared mailbox directory, because it does not have the
2470 &"sticky bit"& set on it. By default, Exim tries to create a lock file before
2471 writing to a mailbox file, and if it cannot create the lock file, the delivery
2472 is deferred. You can get round this either by setting the &"sticky bit"& on the
2473 directory, or by setting a specific group for local deliveries and allowing
2474 that group to create files in the directory (see the comments above the
2475 &(local_delivery)& transport in the default configuration file). Another
2476 approach is to configure Exim not to use lock files, but just to rely on
2477 &[fcntl()]& locking instead. However, you should do this only if all user
2478 agents also use &[fcntl()]& locking. For further discussion of locking issues,
2479 see chapter &<<CHAPappendfile>>&.
2481 One thing that cannot be tested on a system that is already running an MTA is
2482 the receipt of incoming SMTP mail on the standard SMTP port. However, the
2483 &%-oX%& option can be used to run an Exim daemon that listens on some other
2484 port, or &'inetd'& can be used to do this. The &%-bh%& option and the
2485 &'exim_checkaccess'& utility can be used to check out policy controls on
2486 incoming SMTP mail.
2488 Testing a new version on a system that is already running Exim can most easily
2489 be done by building a binary with a different CONFIGURE_FILE setting. From
2490 within the runtime configuration, all other file and directory names
2491 that Exim uses can be altered, in order to keep it entirely clear of the
2492 production version.
2495 .section "Replacing another MTA with Exim" "SECID35"
2496 .cindex "replacing another MTA"
2497 Building and installing Exim for the first time does not of itself put it in
2498 general use. The name by which the system's MTA is called by mail user agents
2499 is either &_/usr/sbin/sendmail_&, or &_/usr/lib/sendmail_& (depending on the
2500 operating system), and it is necessary to make this name point to the &'exim'&
2501 binary in order to get the user agents to pass messages to Exim. This is
2502 normally done by renaming any existing file and making &_/usr/sbin/sendmail_&
2503 or &_/usr/lib/sendmail_&
2504 .cindex "symbolic link" "to &'exim'& binary"
2505 a symbolic link to the &'exim'& binary. It is a good idea to remove any setuid
2506 privilege and executable status from the old MTA. It is then necessary to stop
2507 and restart the mailer daemon, if one is running.
2509 .cindex "FreeBSD, MTA indirection"
2510 .cindex "&_/etc/mail/mailer.conf_&"
2511 Some operating systems have introduced alternative ways of switching MTAs. For
2512 example, if you are running FreeBSD, you need to edit the file
2513 &_/etc/mail/mailer.conf_& instead of setting up a symbolic link as just
2514 described. A typical example of the contents of this file for running Exim is
2515 as follows:
2516 .code
2517 sendmail /usr/exim/bin/exim
2518 send-mail /usr/exim/bin/exim
2519 mailq /usr/exim/bin/exim -bp
2520 newaliases /usr/bin/true
2521 .endd
2522 Once you have set up the symbolic link, or edited &_/etc/mail/mailer.conf_&,
2523 your Exim installation is &"live"&. Check it by sending a message from your
2524 favourite user agent.
2526 You should consider what to tell your users about the change of MTA. Exim may
2527 have different capabilities to what was previously running, and there are
2528 various operational differences such as the text of messages produced by
2529 command line options and in bounce messages. If you allow your users to make
2530 use of Exim's filtering capabilities, you should make the document entitled
2531 &'Exim's interface to mail filtering'& available to them.
2535 .section "Upgrading Exim" "SECID36"
2536 .cindex "upgrading Exim"
2537 If you are already running Exim on your host, building and installing a new
2538 version automatically makes it available to MUAs, or any other programs that
2539 call the MTA directly. However, if you are running an Exim daemon, you do need
2540 .cindex restart "on HUP signal"
2541 .cindex signal "HUP, to restart"
2542 to send it a HUP signal, to make it re-execute itself, and thereby pick up the
2543 new binary. You do not need to stop processing mail in order to install a new
2544 version of Exim. The install script does not modify an existing runtime
2545 configuration file.
2550 .section "Stopping the Exim daemon on Solaris" "SECID37"
2551 .cindex "Solaris" "stopping Exim on"
2552 The standard command for stopping the mailer daemon on Solaris is
2553 .code
2554 /etc/init.d/sendmail stop
2555 .endd
2556 If &_/usr/lib/sendmail_& has been turned into a symbolic link, this script
2557 fails to stop Exim because it uses the command &'ps -e'& and greps the output
2558 for the text &"sendmail"&; this is not present because the actual program name
2559 (that is, &"exim"&) is given by the &'ps'& command with these options. A
2560 solution is to replace the line that finds the process id with something like
2561 .code
2562 pid=`cat /var/spool/exim/exim-daemon.pid`
2563 .endd
2564 to obtain the daemon's pid directly from the file that Exim saves it in.
2566 Note, however, that stopping the daemon does not &"stop Exim"&. Messages can
2567 still be received from local processes, and if automatic delivery is configured
2568 (the normal case), deliveries will still occur.
2573 . ////////////////////////////////////////////////////////////////////////////
2574 . ////////////////////////////////////////////////////////////////////////////
2576 .chapter "The Exim command line" "CHAPcommandline"
2577 .scindex IIDclo1 "command line" "options"
2578 .scindex IIDclo2 "options" "command line"
2579 Exim's command line takes the standard Unix form of a sequence of options,
2580 each starting with a hyphen character, followed by a number of arguments. The
2581 options are compatible with the main options of Sendmail, and there are also
2582 some additional options, some of which are compatible with Smail 3. Certain
2583 combinations of options do not make sense, and provoke an error if used.
2584 The form of the arguments depends on which options are set.
2587 .section "Setting options by program name" "SECID38"
2588 .cindex "&'mailq'&"
2589 If Exim is called under the name &'mailq'&, it behaves as if the option &%-bp%&
2590 were present before any other options.
2591 The &%-bp%& option requests a listing of the contents of the mail queue on the
2592 standard output.
2593 This feature is for compatibility with some systems that contain a command of
2594 that name in one of the standard libraries, symbolically linked to
2595 &_/usr/sbin/sendmail_& or &_/usr/lib/sendmail_&.
2597 .cindex "&'rsmtp'&"
2598 If Exim is called under the name &'rsmtp'& it behaves as if the option &%-bS%&
2599 were present before any other options, for compatibility with Smail. The
2600 &%-bS%& option is used for reading in a number of messages in batched SMTP
2601 format.
2603 .cindex "&'rmail'&"
2604 If Exim is called under the name &'rmail'& it behaves as if the &%-i%& and
2605 &%-oee%& options were present before any other options, for compatibility with
2606 Smail. The name &'rmail'& is used as an interface by some UUCP systems.
2608 .cindex "&'runq'&"
2609 .cindex "queue runner"
2610 If Exim is called under the name &'runq'& it behaves as if the option &%-q%&
2611 were present before any other options, for compatibility with Smail. The &%-q%&
2612 option causes a single queue runner process to be started.
2614 .cindex "&'newaliases'&"
2615 .cindex "alias file" "building"
2616 .cindex "Sendmail compatibility" "calling Exim as &'newaliases'&"
2617 If Exim is called under the name &'newaliases'& it behaves as if the option
2618 &%-bi%& were present before any other options, for compatibility with Sendmail.
2619 This option is used for rebuilding Sendmail's alias file. Exim does not have
2620 the concept of a single alias file, but can be configured to run a given
2621 command if called with the &%-bi%& option.
2624 .section "Trusted and admin users" "SECTtrustedadmin"
2625 Some Exim options are available only to &'trusted users'& and others are
2626 available only to &'admin users'&. In the description below, the phrases &"Exim
2627 user"& and &"Exim group"& mean the user and group defined by EXIM_USER and
2628 EXIM_GROUP in &_Local/Makefile_& or set by the &%exim_user%& and
2629 &%exim_group%& options. These do not necessarily have to use the name &"exim"&.
2631 .ilist
2632 .cindex "trusted users" "definition of"
2633 .cindex "user" "trusted definition of"
2634 The trusted users are root, the Exim user, any user listed in the
2635 &%trusted_users%& configuration option, and any user whose current group or any
2636 supplementary group is one of those listed in the &%trusted_groups%&
2637 configuration option. Note that the Exim group is not automatically trusted.
2639 .cindex '&"From"& line'
2640 .cindex "envelope from"
2641 .cindex "envelope sender"
2642 Trusted users are always permitted to use the &%-f%& option or a leading
2643 &"From&~"& line to specify the envelope sender of a message that is passed to
2644 Exim through the local interface (see the &%-bm%& and &%-f%& options below).
2645 See the &%untrusted_set_sender%& option for a way of permitting non-trusted
2646 users to set envelope senders.
2648 .cindex "&'From:'& header line"
2649 .cindex "&'Sender:'& header line"
2650 .cindex "header lines" "From:"
2651 .cindex "header lines" "Sender:"
2652 For a trusted user, there is never any check on the contents of the &'From:'&
2653 header line, and a &'Sender:'& line is never added. Furthermore, any existing
2654 &'Sender:'& line in incoming local (non-TCP/IP) messages is not removed.
2656 Trusted users may also specify a host name, host address, interface address,
2657 protocol name, ident value, and authentication data when submitting a message
2658 locally. Thus, they are able to insert messages into Exim's queue locally that
2659 have the characteristics of messages received from a remote host. Untrusted
2660 users may in some circumstances use &%-f%&, but can never set the other values
2661 that are available to trusted users.
2662 .next
2663 .cindex "user" "admin definition of"
2664 .cindex "admin user" "definition of"
2665 The admin users are root, the Exim user, and any user that is a member of the
2666 Exim group or of any group listed in the &%admin_groups%& configuration option.
2667 The current group does not have to be one of these groups.
2669 Admin users are permitted to list the queue, and to carry out certain
2670 operations on messages, for example, to force delivery failures. It is also
2671 necessary to be an admin user in order to see the full information provided by
2672 the Exim monitor, and full debugging output.
2674 By default, the use of the &%-M%&, &%-q%&, &%-R%&, and &%-S%& options to cause
2675 Exim to attempt delivery of messages on its queue is restricted to admin users.
2676 However, this restriction can be relaxed by setting the &%prod_requires_admin%&
2677 option false (that is, specifying &%no_prod_requires_admin%&).
2679 Similarly, the use of the &%-bp%& option to list all the messages in the queue
2680 is restricted to admin users unless &%queue_list_requires_admin%& is set
2681 false.
2682 .endlist
2685 &*Warning*&: If you configure your system so that admin users are able to
2686 edit Exim's configuration file, you are giving those users an easy way of
2687 getting root. There is further discussion of this issue at the start of chapter
2688 &<<CHAPconf>>&.
2693 .section "Command line options" "SECID39"
2694 Exim's command line options are described in alphabetical order below. If none
2695 of the options that specifies a specific action (such as starting the daemon or
2696 a queue runner, or testing an address, or receiving a message in a specific
2697 format, or listing the queue) are present, and there is at least one argument
2698 on the command line, &%-bm%& (accept a local message on the standard input,
2699 with the arguments specifying the recipients) is assumed. Otherwise, Exim
2700 outputs a brief message about itself and exits.
2702 . ////////////////////////////////////////////////////////////////////////////
2703 . Insert a stylized XML comment here, to identify the start of the command line
2704 . options. This is for the benefit of the Perl script that automatically
2705 . creates a man page for the options.
2706 . ////////////////////////////////////////////////////////////////////////////
2708 .literal xml
2709 <!-- === Start of command line options === -->
2710 .literal off
2713 .vlist
2714 .vitem &%--%&
2715 .oindex "--"
2716 .cindex "options" "command line; terminating"
2717 This is a pseudo-option whose only purpose is to terminate the options and
2718 therefore to cause subsequent command line items to be treated as arguments
2719 rather than options, even if they begin with hyphens.
2721 .vitem &%--help%&
2722 .oindex "&%--help%&"
2723 This option causes Exim to output a few sentences stating what it is.
2724 The same output is generated if the Exim binary is called with no options and
2725 no arguments.
2727 .vitem &%--version%&
2728 .oindex "&%--version%&"
2729 This option is an alias for &%-bV%& and causes version information to be
2730 displayed.
2732 .vitem &%-Ac%& &&&
2733 &%-Am%&
2734 .oindex "&%-Ac%&"
2735 .oindex "&%-Am%&"
2736 These options are used by Sendmail for selecting configuration files and are
2737 ignored by Exim.
2739 .vitem &%-B%&<&'type'&>
2740 .oindex "&%-B%&"
2741 .cindex "8-bit characters"
2742 .cindex "Sendmail compatibility" "8-bit characters"
2743 This is a Sendmail option for selecting 7 or 8 bit processing. Exim is 8-bit
2744 clean; it ignores this option.
2746 .vitem &%-bd%&
2747 .oindex "&%-bd%&"
2748 .cindex "daemon"
2749 .cindex "SMTP" "listener"
2750 .cindex "queue runner"
2751 This option runs Exim as a daemon, awaiting incoming SMTP connections. Usually
2752 the &%-bd%& option is combined with the &%-q%&<&'time'&> option, to specify
2753 that the daemon should also initiate periodic queue runs.
2755 The &%-bd%& option can be used only by an admin user. If either of the &%-d%&
2756 (debugging) or &%-v%& (verifying) options are set, the daemon does not
2757 disconnect from the controlling terminal. When running this way, it can be
2758 stopped by pressing ctrl-C.
2760 By default, Exim listens for incoming connections to the standard SMTP port on
2761 all the host's running interfaces. However, it is possible to listen on other
2762 ports, on multiple ports, and only on specific interfaces. Chapter
2763 &<<CHAPinterfaces>>& contains a description of the options that control this.
2765 When a listening daemon
2766 .cindex "daemon" "process id (pid)"
2767 .cindex "pid (process id)" "of daemon"
2768 is started without the use of &%-oX%& (that is, without overriding the normal
2769 configuration), it writes its process id to a file called &_exim-daemon.pid_&
2770 in Exim's spool directory. This location can be overridden by setting
2771 PID_FILE_PATH in &_Local/Makefile_&. The file is written while Exim is still
2772 running as root.
2774 When &%-oX%& is used on the command line to start a listening daemon, the
2775 process id is not written to the normal pid file path. However, &%-oP%& can be
2776 used to specify a path on the command line if a pid file is required.
2778 The SIGHUP signal
2779 .cindex "SIGHUP"
2780 .cindex restart "on HUP signal"
2781 .cindex signal "HUP, to restart"
2782 .cindex "daemon" "restarting"
2783 .cindex signal "to reload configuration"
2784 .cindex daemon "reload configuration"
2785 .cindex reload configuration
2786 can be used to cause the daemon to re-execute itself. This should be done
2787 whenever Exim's configuration file, or any file that is incorporated into it by
2788 means of the &%.include%& facility, is changed, and also whenever a new version
2789 of Exim is installed. It is not necessary to do this when other files that are
2790 referenced from the configuration (for example, alias files) are changed,
2791 because these are reread each time they are used.
2793 .vitem &%-bdf%&
2794 .oindex "&%-bdf%&"
2795 This option has the same effect as &%-bd%& except that it never disconnects
2796 from the controlling terminal, even when no debugging is specified.
2798 .vitem &%-be%&
2799 .oindex "&%-be%&"
2800 .cindex "testing" "string expansion"
2801 .cindex "expansion" "testing"
2802 Run Exim in expansion testing mode. Exim discards its root privilege, to
2803 prevent ordinary users from using this mode to read otherwise inaccessible
2804 files. If no arguments are given, Exim runs interactively, prompting for lines
2805 of data. Otherwise, it processes each argument in turn.
2807 If Exim was built with USE_READLINE=yes in &_Local/Makefile_&, it tries
2808 to load the &%libreadline%& library dynamically whenever the &%-be%& option is
2809 used without command line arguments. If successful, it uses the &[readline()]&
2810 function, which provides extensive line-editing facilities, for reading the
2811 test data. A line history is supported.
2813 Long expansion expressions can be split over several lines by using backslash
2814 continuations. As in Exim's runtime configuration, white space at the start of
2815 continuation lines is ignored. Each argument or data line is passed through the
2816 string expansion mechanism, and the result is output. Variable values from the
2817 configuration file (for example, &$qualify_domain$&) are available, but no
2818 message-specific values (such as &$message_exim_id$&) are set, because no message
2819 is being processed (but see &%-bem%& and &%-Mset%&).
2821 &*Note*&: If you use this mechanism to test lookups, and you change the data
2822 files or databases you are using, you must exit and restart Exim before trying
2823 the same lookup again. Otherwise, because each Exim process caches the results
2824 of lookups, you will just get the same result as before.
2826 Macro processing is done on lines before string-expansion: new macros can be
2827 defined and macros will be expanded.
2828 Because macros in the config file are often used for secrets, those are only
2829 available to admin users.
2831 .vitem &%-bem%&&~<&'filename'&>
2832 .oindex "&%-bem%&"
2833 .cindex "testing" "string expansion"
2834 .cindex "expansion" "testing"
2835 This option operates like &%-be%& except that it must be followed by the name
2836 of a file. For example:
2837 .code
2838 exim -bem /tmp/testmessage
2839 .endd
2840 The file is read as a message (as if receiving a locally-submitted non-SMTP
2841 message) before any of the test expansions are done. Thus, message-specific
2842 variables such as &$message_size$& and &$header_from:$& are available. However,
2843 no &'Received:'& header is added to the message. If the &%-t%& option is set,
2844 recipients are read from the headers in the normal way, and are shown in the
2845 &$recipients$& variable. Note that recipients cannot be given on the command
2846 line, because further arguments are taken as strings to expand (just like
2847 &%-be%&).
2849 .vitem &%-bF%&&~<&'filename'&>
2850 .oindex "&%-bF%&"
2851 .cindex "system filter" "testing"
2852 .cindex "testing" "system filter"
2853 This option is the same as &%-bf%& except that it assumes that the filter being
2854 tested is a system filter. The additional commands that are available only in
2855 system filters are recognized.
2857 .vitem &%-bf%&&~<&'filename'&>
2858 .oindex "&%-bf%&"
2859 .cindex "filter" "testing"
2860 .cindex "testing" "filter file"
2861 .cindex "forward file" "testing"
2862 .cindex "testing" "forward file"
2863 .cindex "Sieve filter" "testing"
2864 This option runs Exim in user filter testing mode; the file is the filter file
2865 to be tested, and a test message must be supplied on the standard input. If
2866 there are no message-dependent tests in the filter, an empty file can be
2867 supplied.
2869 If you want to test a system filter file, use &%-bF%& instead of &%-bf%&. You
2870 can use both &%-bF%& and &%-bf%& on the same command, in order to test a system
2871 filter and a user filter in the same run. For example:
2872 .code
2873 exim -bF /system/filter -bf /user/filter </test/message
2874 .endd
2875 This is helpful when the system filter adds header lines or sets filter
2876 variables that are used by the user filter.
2878 If the test filter file does not begin with one of the special lines
2879 .code
2880 # Exim filter
2881 # Sieve filter
2882 .endd
2883 it is taken to be a normal &_.forward_& file, and is tested for validity under
2884 that interpretation. See sections &<<SECTitenonfilred>>& to
2885 &<<SECTspecitredli>>& for a description of the possible contents of non-filter
2886 redirection lists.
2888 The result of an Exim command that uses &%-bf%&, provided no errors are
2889 detected, is a list of the actions that Exim would try to take if presented
2890 with the message for real. More details of filter testing are given in the
2891 separate document entitled &'Exim's interfaces to mail filtering'&.
2893 When testing a filter file,
2894 .cindex "&""From""& line"
2895 .cindex "envelope from"
2896 .cindex "envelope sender"
2897 .oindex "&%-f%&" "for filter testing"
2898 the envelope sender can be set by the &%-f%& option,
2899 or by a &"From&~"& line at the start of the test message. Various parameters
2900 that would normally be taken from the envelope recipient address of the message
2901 can be set by means of additional command line options (see the next four
2902 options).
2904 .vitem &%-bfd%&&~<&'domain'&>
2905 .oindex "&%-bfd%&"
2906 .vindex "&$qualify_domain$&"
2907 This sets the domain of the recipient address when a filter file is being
2908 tested by means of the &%-bf%& option. The default is the value of
2909 &$qualify_domain$&.
2911 .vitem &%-bfl%&&~<&'local&~part'&>
2912 .oindex "&%-bfl%&"
2913 This sets the local part of the recipient address when a filter file is being
2914 tested by means of the &%-bf%& option. The default is the username of the
2915 process that calls Exim. A local part should be specified with any prefix or
2916 suffix stripped, because that is how it appears to the filter when a message is
2917 actually being delivered.
2919 .vitem &%-bfp%&&~<&'prefix'&>
2920 .oindex "&%-bfp%&"
2921 .cindex affix "filter testing"
2922 This sets the prefix of the local part of the recipient address when a filter
2923 file is being tested by means of the &%-bf%& option. The default is an empty
2924 prefix.
2926 .vitem &%-bfs%&&~<&'suffix'&>
2927 .oindex "&%-bfs%&"
2928 .cindex affix "filter testing"
2929 This sets the suffix of the local part of the recipient address when a filter
2930 file is being tested by means of the &%-bf%& option. The default is an empty
2931 suffix.
2933 .vitem &%-bh%&&~<&'IP&~address'&>
2934 .oindex "&%-bh%&"
2935 .cindex "testing" "incoming SMTP"
2936 .cindex "SMTP" "testing incoming"
2937 .cindex "testing" "relay control"
2938 .cindex "relaying" "testing configuration"
2939 .cindex "policy control" "testing"
2940 .cindex "debugging" "&%-bh%& option"
2941 This option runs a fake SMTP session as if from the given IP address, using the
2942 standard input and output. The IP address may include a port number at the end,
2943 after a full stop. For example:
2944 .code
2945 exim -bh
2946 exim -bh fe80::a00:20ff:fe86:a061.5678
2947 .endd
2948 When an IPv6 address is given, it is converted into canonical form. In the case
2949 of the second example above, the value of &$sender_host_address$& after
2950 conversion to the canonical form is
2951 &`fe80:0000:0000:0a00:20ff:fe86:a061.5678`&.
2953 Comments as to what is going on are written to the standard error file. These
2954 include lines beginning with &"LOG"& for anything that would have been logged.
2955 This facility is provided for testing configuration options for incoming
2956 messages, to make sure they implement the required policy. For example, you can
2957 test your relay controls using &%-bh%&.
2959 &*Warning 1*&:
2960 .cindex "RFC 1413"
2961 You can test features of the configuration that rely on ident (RFC 1413)
2962 information by using the &%-oMt%& option. However, Exim cannot actually perform
2963 an ident callout when testing using &%-bh%& because there is no incoming SMTP
2964 connection.
2966 &*Warning 2*&: Address verification callouts (see section &<<SECTcallver>>&)
2967 are also skipped when testing using &%-bh%&. If you want these callouts to
2968 occur, use &%-bhc%& instead.
2970 Messages supplied during the testing session are discarded, and nothing is
2971 written to any of the real log files. There may be pauses when DNS (and other)
2972 lookups are taking place, and of course these may time out. The &%-oMi%& option
2973 can be used to specify a specific IP interface and port if this is important,
2974 and &%-oMaa%& and &%-oMai%& can be used to set parameters as if the SMTP
2975 session were authenticated.
2977 The &'exim_checkaccess'& utility is a &"packaged"& version of &%-bh%& whose
2978 output just states whether a given recipient address from a given host is
2979 acceptable or not. See section &<<SECTcheckaccess>>&.
2981 Features such as authentication and encryption, where the client input is not
2982 plain text, cannot easily be tested with &%-bh%&. Instead, you should use a
2983 specialized SMTP test program such as
2984 &url(https://www.jetmore.org/john/code/swaks/,swaks).
2986 .vitem &%-bhc%&&~<&'IP&~address'&>
2987 .oindex "&%-bhc%&"
2988 This option operates in the same way as &%-bh%&, except that address
2989 verification callouts are performed if required. This includes consulting and
2990 updating the callout cache database.
2992 .vitem &%-bi%&
2993 .oindex "&%-bi%&"
2994 .cindex "alias file" "building"
2995 .cindex "building alias file"
2996 .cindex "Sendmail compatibility" "&%-bi%& option"
2997 Sendmail interprets the &%-bi%& option as a request to rebuild its alias file.
2998 Exim does not have the concept of a single alias file, and so it cannot mimic
2999 this behaviour. However, calls to &_/usr/lib/sendmail_& with the &%-bi%& option
3000 tend to appear in various scripts such as NIS make files, so the option must be
3001 recognized.
3003 If &%-bi%& is encountered, the command specified by the &%bi_command%&
3004 configuration option is run, under the uid and gid of the caller of Exim. If
3005 the &%-oA%& option is used, its value is passed to the command as an argument.
3006 The command set by &%bi_command%& may not contain arguments. The command can
3007 use the &'exim_dbmbuild'& utility, or some other means, to rebuild alias files
3008 if this is required. If the &%bi_command%& option is not set, calling Exim with
3009 &%-bi%& is a no-op.
3011 . // Keep :help first, then the rest in alphabetical order
3012 .vitem &%-bI:help%&
3013 .oindex "&%-bI:help%&"
3014 .cindex "querying exim information"
3015 We shall provide various options starting &`-bI:`& for querying Exim for
3016 information. The output of many of these will be intended for machine
3017 consumption. This one is not. The &%-bI:help%& option asks Exim for a
3018 synopsis of supported options beginning &`-bI:`&. Use of any of these
3019 options shall cause Exim to exit after producing the requested output.
3021 .vitem &%-bI:dscp%&
3022 .oindex "&%-bI:dscp%&"
3023 .cindex "DSCP" "values"
3024 This option causes Exim to emit an alphabetically sorted list of all
3025 recognised DSCP names.
3027 .vitem &%-bI:sieve%&
3028 .oindex "&%-bI:sieve%&"
3029 .cindex "Sieve filter" "capabilities"
3030 This option causes Exim to emit an alphabetically sorted list of all supported
3031 Sieve protocol extensions on stdout, one per line. This is anticipated to be
3032 useful for ManageSieve (RFC 5804) implementations, in providing that protocol's
3033 &`SIEVE`& capability response line. As the precise list may depend upon
3034 compile-time build options, which this option will adapt to, this is the only
3035 way to guarantee a correct response.
3037 .vitem &%-bm%&
3038 .oindex "&%-bm%&"
3039 .cindex "local message reception"
3040 This option runs an Exim receiving process that accepts an incoming,
3041 locally-generated message on the standard input. The recipients are given as the
3042 command arguments (except when &%-t%& is also present &-- see below). Each
3043 argument can be a comma-separated list of RFC 2822 addresses. This is the
3044 default option for selecting the overall action of an Exim call; it is assumed
3045 if no other conflicting option is present.
3047 If any addresses in the message are unqualified (have no domain), they are
3048 qualified by the values of the &%qualify_domain%& or &%qualify_recipient%&
3049 options, as appropriate. The &%-bnq%& option (see below) provides a way of
3050 suppressing this for special cases.
3052 Policy checks on the contents of local messages can be enforced by means of
3053 the non-SMTP ACL. See chapter &<<CHAPACL>>& for details.
3055 .cindex "return code" "for &%-bm%&"
3056 The return code is zero if the message is successfully accepted. Otherwise, the
3057 action is controlled by the &%-oe%&&'x'& option setting &-- see below.
3059 The format
3060 .cindex "message" "format"
3061 .cindex "format" "message"
3062 .cindex "&""From""& line"
3063 .cindex "UUCP" "&""From""& line"
3064 .cindex "Sendmail compatibility" "&""From""& line"
3065 of the message must be as defined in RFC 2822, except that, for
3066 compatibility with Sendmail and Smail, a line in one of the forms
3067 .code
3068 From sender Fri Jan 5 12:55 GMT 1997
3069 From sender Fri, 5 Jan 97 12:55:01
3070 .endd
3071 (with the weekday optional, and possibly with additional text after the date)
3072 is permitted to appear at the start of the message. There appears to be no
3073 authoritative specification of the format of this line. Exim recognizes it by
3074 matching against the regular expression defined by the &%uucp_from_pattern%&
3075 option, which can be changed if necessary.
3077 .oindex "&%-f%&" "overriding &""From""& line"
3078 The specified sender is treated as if it were given as the argument to the
3079 &%-f%& option, but if a &%-f%& option is also present, its argument is used in
3080 preference to the address taken from the message. The caller of Exim must be a
3081 trusted user for the sender of a message to be set in this way.
3083 .vitem &%-bmalware%&&~<&'filename'&>
3084 .oindex "&%-bmalware%&"
3085 .cindex "testing", "malware"
3086 .cindex "malware scan test"
3087 This debugging option causes Exim to scan the given file or directory
3088 (depending on the used scanner interface),
3089 using the malware scanning framework. The option of &%av_scanner%& influences
3090 this option, so if &%av_scanner%&'s value is dependent upon an expansion then
3091 the expansion should have defaults which apply to this invocation. ACLs are
3092 not invoked, so if &%av_scanner%& references an ACL variable then that variable
3093 will never be populated and &%-bmalware%& will fail.
3095 Exim will have changed working directory before resolving the filename, so
3096 using fully qualified pathnames is advisable. Exim will be running as the Exim
3097 user when it tries to open the file, rather than as the invoking user.
3098 This option requires admin privileges.
3100 The &%-bmalware%& option will not be extended to be more generally useful,
3101 there are better tools for file-scanning. This option exists to help
3102 administrators verify their Exim and AV scanner configuration.
3104 .vitem &%-bnq%&
3105 .oindex "&%-bnq%&"
3106 .cindex "address qualification, suppressing"
3107 By default, Exim automatically qualifies unqualified addresses (those
3108 without domains) that appear in messages that are submitted locally (that
3109 is, not over TCP/IP). This qualification applies both to addresses in
3110 envelopes, and addresses in header lines. Sender addresses are qualified using
3111 &%qualify_domain%&, and recipient addresses using &%qualify_recipient%& (which
3112 defaults to the value of &%qualify_domain%&).
3114 Sometimes, qualification is not wanted. For example, if &%-bS%& (batch SMTP) is
3115 being used to re-submit messages that originally came from remote hosts after
3116 content scanning, you probably do not want to qualify unqualified addresses in
3117 header lines. (Such lines will be present only if you have not enabled a header
3118 syntax check in the appropriate ACL.)
3120 The &%-bnq%& option suppresses all qualification of unqualified addresses in
3121 messages that originate on the local host. When this is used, unqualified
3122 addresses in the envelope provoke errors (causing message rejection) and
3123 unqualified addresses in header lines are left alone.
3126 .vitem &%-bP%&
3127 .oindex "&%-bP%&"
3128 .cindex "configuration options" "extracting"
3129 .cindex "options" "configuration &-- extracting"
3130 If this option is given with no arguments, it causes the values of all Exim's
3131 main configuration options to be written to the standard output. The values
3132 of one or more specific options can be requested by giving their names as
3133 arguments, for example:
3134 .code
3135 exim -bP qualify_domain hold_domains
3136 .endd
3137 .cindex "hiding configuration option values"
3138 .cindex "configuration options" "hiding value of"
3139 .cindex "options" "hiding value of"
3140 However, any option setting that is preceded by the word &"hide"& in the
3141 configuration file is not shown in full, except to an admin user. For other
3142 users, the output is as in this example:
3143 .code
3144 mysql_servers = <value not displayable>
3145 .endd
3146 If &%config%& is given as an argument, the config is
3147 output, as it was parsed, any include file resolved, any comment removed.
3149 If &%config_file%& is given as an argument, the name of the runtime
3150 configuration file is output. (&%configure_file%& works too, for
3151 backward compatibility.)
3152 If a list of configuration files was supplied, the value that is output here
3153 is the name of the file that was actually used.
3155 .cindex "options" "hiding name of"
3156 If the &%-n%& flag is given, then for most modes of &%-bP%& operation the
3157 name will not be output.
3159 .cindex "daemon" "process id (pid)"
3160 .cindex "pid (process id)" "of daemon"
3161 If &%log_file_path%& or &%pid_file_path%& are given, the names of the
3162 directories where log files and daemon pid files are written are output,
3163 respectively. If these values are unset, log files are written in a
3164 sub-directory of the spool directory called &%log%&, and the pid file is
3165 written directly into the spool directory.
3167 If &%-bP%& is followed by a name preceded by &`+`&, for example,
3168 .code
3169 exim -bP +local_domains
3170 .endd
3171 it searches for a matching named list of any type (domain, host, address, or
3172 local part) and outputs what it finds.
3174 .cindex "options" "router &-- extracting"
3175 .cindex "options" "transport &-- extracting"
3176 .cindex "options" "authenticator &-- extracting"
3177 If one of the words &%router%&, &%transport%&, or &%authenticator%& is given,
3178 followed by the name of an appropriate driver instance, the option settings for
3179 that driver are output. For example:
3180 .code
3181 exim -bP transport local_delivery
3182 .endd
3183 The generic driver options are output first, followed by the driver's private
3184 options. A list of the names of drivers of a particular type can be obtained by
3185 using one of the words &%router_list%&, &%transport_list%&, or
3186 &%authenticator_list%&, and a complete list of all drivers with their option
3187 settings can be obtained by using &%routers%&, &%transports%&, or
3188 &%authenticators%&.
3190 .cindex "environment"
3191 If &%environment%& is given as an argument, the set of environment
3192 variables is output, line by line. Using the &%-n%& flag suppresses the value of the
3193 variables.
3195 .cindex "options" "macro &-- extracting"
3196 If invoked by an admin user, then &%macro%&, &%macro_list%& and &%macros%&
3197 are available, similarly to the drivers. Because macros are sometimes used
3198 for storing passwords, this option is restricted.
3199 The output format is one item per line.
3200 For the "-bP macro <name>" form, if no such macro is found
3201 the exit status will be nonzero.
3203 .vitem &%-bp%&
3204 .oindex "&%-bp%&"
3205 .cindex "queue" "listing messages in"
3206 .cindex "listing" "messages in the queue"
3207 This option requests a listing of the contents of the mail queue on the
3208 standard output. If the &%-bp%& option is followed by a list of message ids,
3209 just those messages are listed. By default, this option can be used only by an
3210 admin user. However, the &%queue_list_requires_admin%& option can be set false
3211 to allow any user to see the queue.
3213 Each message in the queue is displayed as in the following example:
3214 .code
3215 25m 2.9K 0t5C6f-0000c8-00 <alice@wonderland.fict.example>
3216 red.king@looking-glass.fict.example
3217 <other addresses>
3218 .endd
3219 .cindex "message" "size in queue listing"
3220 .cindex "size" "of message"
3221 The first line contains the length of time the message has been in the queue
3222 (in this case 25 minutes), the size of the message (2.9K), the unique local
3223 identifier for the message, and the message sender, as contained in the
3224 envelope. For bounce messages, the sender address is empty, and appears as
3225 &"<>"&. If the message was submitted locally by an untrusted user who overrode
3226 the default sender address, the user's login name is shown in parentheses
3227 before the sender address.
3229 .cindex "frozen messages" "in queue listing"
3230 If the message is frozen (attempts to deliver it are suspended) then the text
3231 &"*** frozen ***"& is displayed at the end of this line.
3233 The recipients of the message (taken from the envelope, not the headers) are
3234 displayed on subsequent lines. Those addresses to which the message has already
3235 been delivered are marked with the letter D. If an original address gets
3236 expanded into several addresses via an alias or forward file, the original is
3237 displayed with a D only when deliveries for all of its child addresses are
3238 complete.
3241 .vitem &%-bpa%&
3242 .oindex "&%-bpa%&"
3243 This option operates like &%-bp%&, but in addition it shows delivered addresses
3244 that were generated from the original top level address(es) in each message by
3245 alias or forwarding operations. These addresses are flagged with &"+D"& instead
3246 of just &"D"&.
3249 .vitem &%-bpc%&
3250 .oindex "&%-bpc%&"
3251 .cindex "queue" "count of messages on"
3252 This option counts the number of messages in the queue, and writes the total
3253 to the standard output. It is restricted to admin users, unless
3254 &%queue_list_requires_admin%& is set false.
3257 .vitem &%-bpr%&
3258 .oindex "&%-bpr%&"
3259 This option operates like &%-bp%&, but the output is not sorted into
3260 chronological order of message arrival. This can speed it up when there are
3261 lots of messages in the queue, and is particularly useful if the output is
3262 going to be post-processed in a way that doesn't need the sorting.
3264 .vitem &%-bpra%&
3265 .oindex "&%-bpra%&"
3266 This option is a combination of &%-bpr%& and &%-bpa%&.
3268 .vitem &%-bpru%&
3269 .oindex "&%-bpru%&"
3270 This option is a combination of &%-bpr%& and &%-bpu%&.
3273 .vitem &%-bpu%&
3274 .oindex "&%-bpu%&"
3275 This option operates like &%-bp%& but shows only undelivered top-level
3276 addresses for each message displayed. Addresses generated by aliasing or
3277 forwarding are not shown, unless the message was deferred after processing by a
3278 router with the &%one_time%& option set.
3281 .vitem &%-brt%&
3282 .oindex "&%-brt%&"
3283 .cindex "testing" "retry configuration"
3284 .cindex "retry" "configuration testing"
3285 This option is for testing retry rules, and it must be followed by up to three
3286 arguments. It causes Exim to look for a retry rule that matches the values
3287 and to write it to the standard output. For example:
3288 .code
3289 exim -brt bach.comp.mus.example
3290 Retry rule: *.comp.mus.example F,2h,15m; F,4d,30m;
3291 .endd
3292 See chapter &<<CHAPretry>>& for a description of Exim's retry rules. The first
3293 argument, which is required, can be a complete address in the form
3294 &'local_part@domain'&, or it can be just a domain name. If the second argument
3295 contains a dot, it is interpreted as an optional second domain name; if no
3296 retry rule is found for the first argument, the second is tried. This ties in
3297 with Exim's behaviour when looking for retry rules for remote hosts &-- if no
3298 rule is found that matches the host, one that matches the mail domain is
3299 sought. Finally, an argument that is the name of a specific delivery error, as
3300 used in setting up retry rules, can be given. For example:
3301 .code
3302 exim -brt haydn.comp.mus.example quota_3d
3303 Retry rule: *@haydn.comp.mus.example quota_3d F,1h,15m
3304 .endd
3306 .vitem &%-brw%&
3307 .oindex "&%-brw%&"
3308 .cindex "testing" "rewriting"
3309 .cindex "rewriting" "testing"
3310 This option is for testing address rewriting rules, and it must be followed by
3311 a single argument, consisting of either a local part without a domain, or a
3312 complete address with a fully qualified domain. Exim outputs how this address
3313 would be rewritten for each possible place it might appear. See chapter
3314 &<<CHAPrewrite>>& for further details.
3316 .vitem &%-bS%&
3317 .oindex "&%-bS%&"
3318 .cindex "SMTP" "batched incoming"
3319 .cindex "batched SMTP input"
3320 This option is used for batched SMTP input, which is an alternative interface
3321 for non-interactive local message submission. A number of messages can be
3322 submitted in a single run. However, despite its name, this is not really SMTP
3323 input. Exim reads each message's envelope from SMTP commands on the standard
3324 input, but generates no responses. If the caller is trusted, or
3325 &%untrusted_set_sender%& is set, the senders in the SMTP MAIL commands are
3326 believed; otherwise the sender is always the caller of Exim.
3328 The message itself is read from the standard input, in SMTP format (leading
3329 dots doubled), terminated by a line containing just a single dot. An error is
3330 provoked if the terminating dot is missing. A further message may then follow.
3332 As for other local message submissions, the contents of incoming batch SMTP
3333 messages can be checked using the non-SMTP ACL (see chapter &<<CHAPACL>>&).
3334 Unqualified addresses are automatically qualified using &%qualify_domain%& and
3335 &%qualify_recipient%&, as appropriate, unless the &%-bnq%& option is used.
3337 Some other SMTP commands are recognized in the input. HELO and EHLO act
3338 as RSET; VRFY, EXPN, ETRN, and HELP act as NOOP;
3339 QUIT quits, ignoring the rest of the standard input.
3341 .cindex "return code" "for &%-bS%&"
3342 If any error is encountered, reports are written to the standard output and
3343 error streams, and Exim gives up immediately. The return code is 0 if no error
3344 was detected; it is 1 if one or more messages were accepted before the error
3345 was detected; otherwise it is 2.
3347 More details of input using batched SMTP are given in section
3348 &<<SECTincomingbatchedSMTP>>&.
3350 .vitem &%-bs%&
3351 .oindex "&%-bs%&"
3352 .cindex "SMTP" "local input"
3353 .cindex "local SMTP input"
3354 This option causes Exim to accept one or more messages by reading SMTP commands
3355 on the standard input, and producing SMTP replies on the standard output. SMTP
3356 policy controls, as defined in ACLs (see chapter &<<CHAPACL>>&) are applied.
3357 Some user agents use this interface as a way of passing locally-generated
3358 messages to the MTA.
3360 In
3361 .cindex "sender" "source of"
3362 this usage, if the caller of Exim is trusted, or &%untrusted_set_sender%& is
3363 set, the senders of messages are taken from the SMTP MAIL commands.
3364 Otherwise the content of these commands is ignored and the sender is set up as
3365 the calling user. Unqualified addresses are automatically qualified using
3366 &%qualify_domain%& and &%qualify_recipient%&, as appropriate, unless the
3367 &%-bnq%& option is used.
3369 .cindex "inetd"
3370 The
3371 &%-bs%& option is also used to run Exim from &'inetd'&, as an alternative to
3372 using a listening daemon. Exim can distinguish the two cases by checking
3373 whether the standard input is a TCP/IP socket. When Exim is called from
3374 &'inetd'&, the source of the mail is assumed to be remote, and the comments
3375 above concerning senders and qualification do not apply. In this situation,
3376 Exim behaves in exactly the same way as it does when receiving a message via
3377 the listening daemon.
3379 .vitem &%-bt%&
3380 .oindex "&%-bt%&"
3381 .cindex "testing" "addresses"
3382 .cindex "address" "testing"
3383 This option runs Exim in address testing mode, in which each argument is taken
3384 as a recipient address to be tested for deliverability. The results are
3385 written to the standard output. If a test fails, and the caller is not an admin
3386 user, no details of the failure are output, because these might contain
3387 sensitive information such as usernames and passwords for database lookups.
3389 If no arguments are given, Exim runs in an interactive manner, prompting with a
3390 right angle bracket for addresses to be tested.
3392 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3393 &[readline()]& function, because it is running as &'root'& and there are
3394 security issues.
3396 Each address is handled as if it were the recipient address of a message
3397 (compare the &%-bv%& option). It is passed to the routers and the result is
3398 written to the standard output. However, any router that has
3399 &%no_address_test%& set is bypassed. This can make &%-bt%& easier to use for
3400 genuine routing tests if your first router passes everything to a scanner
3401 program.
3403 .cindex "return code" "for &%-bt%&"
3404 The return code is 2 if any address failed outright; it is 1 if no address
3405 failed outright but at least one could not be resolved for some reason. Return
3406 code 0 is given only when all addresses succeed.
3408 .cindex "duplicate addresses"
3409 &*Note*&: When actually delivering a message, Exim removes duplicate recipient
3410 addresses after routing is complete, so that only one delivery takes place.
3411 This does not happen when testing with &%-bt%&; the full results of routing are
3412 always shown.
3414 &*Warning*&: &%-bt%& can only do relatively simple testing. If any of the
3415 routers in the configuration makes any tests on the sender address of a
3416 message,
3417 .oindex "&%-f%&" "for address testing"
3418 you can use the &%-f%& option to set an appropriate sender when running
3419 &%-bt%& tests. Without it, the sender is assumed to be the calling user at the
3420 default qualifying domain. However, if you have set up (for example) routers
3421 whose behaviour depends on the contents of an incoming message, you cannot test
3422 those conditions using &%-bt%&. The &%-N%& option provides a possible way of
3423 doing such tests.
3425 .vitem &%-bV%&
3426 .oindex "&%-bV%&"
3427 .cindex "version number of Exim"
3428 This option causes Exim to write the current version number, compilation
3429 number, and compilation date of the &'exim'& binary to the standard output.
3430 It also lists the DBM library that is being used, the optional modules (such as
3431 specific lookup types), the drivers that are included in the binary, and the
3432 name of the runtime configuration file that is in use.
3434 As part of its operation, &%-bV%& causes Exim to read and syntax check its
3435 configuration file. However, this is a static check only. It cannot check
3436 values that are to be expanded. For example, although a misspelt ACL verb is
3437 detected, an error in the verb's arguments is not. You cannot rely on &%-bV%&
3438 alone to discover (for example) all the typos in the configuration; some
3439 realistic testing is needed. The &%-bh%& and &%-N%& options provide more
3440 dynamic testing facilities.
3442 .vitem &%-bv%&
3443 .oindex "&%-bv%&"
3444 .cindex "verifying address" "using &%-bv%&"
3445 .cindex "address" "verification"
3446 This option runs Exim in address verification mode, in which each argument is
3447 taken as a recipient address to be verified by the routers. (This does
3448 not involve any verification callouts). During normal operation, verification
3449 happens mostly as a consequence processing a &%verify%& condition in an ACL
3450 (see chapter &<<CHAPACL>>&). If you want to test an entire ACL, possibly
3451 including callouts, see the &%-bh%& and &%-bhc%& options.
3453 If verification fails, and the caller is not an admin user, no details of the
3454 failure are output, because these might contain sensitive information such as
3455 usernames and passwords for database lookups.
3457 If no arguments are given, Exim runs in an interactive manner, prompting with a
3458 right angle bracket for addresses to be verified.
3460 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3461 &[readline()]& function, because it is running as &'exim'& and there are
3462 security issues.
3464 Verification differs from address testing (the &%-bt%& option) in that routers
3465 that have &%no_verify%& set are skipped, and if the address is accepted by a
3466 router that has &%fail_verify%& set, verification fails. The address is
3467 verified as a recipient if &%-bv%& is used; to test verification for a sender
3468 address, &%-bvs%& should be used.
3470 If the &%-v%& option is not set, the output consists of a single line for each
3471 address, stating whether it was verified or not, and giving a reason in the
3472 latter case. Without &%-v%&, generating more than one address by redirection
3473 causes verification to end successfully, without considering the generated
3474 addresses. However, if just one address is generated, processing continues,
3475 and the generated address must verify successfully for the overall verification
3476 to succeed.
3478 When &%-v%& is set, more details are given of how the address has been handled,
3479 and in the case of address redirection, all the generated addresses are also
3480 considered. Verification may succeed for some and fail for others.
3482 The
3483 .cindex "return code" "for &%-bv%&"
3484 return code is 2 if any address failed outright; it is 1 if no address
3485 failed outright but at least one could not be resolved for some reason. Return
3486 code 0 is given only when all addresses succeed.
3488 If any of the routers in the configuration makes any tests on the sender
3489 address of a message, you should use the &%-f%& option to set an appropriate
3490 sender when running &%-bv%& tests. Without it, the sender is assumed to be the
3491 calling user at the default qualifying domain.
3493 .vitem &%-bvs%&
3494 .oindex "&%-bvs%&"
3495 This option acts like &%-bv%&, but verifies the address as a sender rather
3496 than a recipient address. This affects any rewriting and qualification that
3497 might happen.
3499 .vitem &%-bw%&
3500 .oindex "&%-bw%&"
3501 .cindex "daemon"
3502 .cindex "inetd"
3503 .cindex "inetd" "wait mode"
3504 This option runs Exim as a daemon, awaiting incoming SMTP connections,
3505 similarly to the &%-bd%& option. All port specifications on the command-line
3506 and in the configuration file are ignored. Queue-running may not be specified.
3508 In this mode, Exim expects to be passed a socket as fd 0 (stdin) which is
3509 listening for connections. This permits the system to start up and have
3510 inetd (or equivalent) listen on the SMTP ports, starting an Exim daemon for
3511 each port only when the first connection is received.
3513 If the option is given as &%-bw%&<&'time'&> then the time is a timeout, after
3514 which the daemon will exit, which should cause inetd to listen once more.
3516 .vitem &%-C%&&~<&'filelist'&>
3517 .oindex "&%-C%&"
3518 .cindex "configuration file" "alternate"
3519 .cindex "CONFIGURE_FILE"
3520 .cindex "alternate configuration file"
3521 This option causes Exim to find the runtime configuration file from the given
3522 list instead of from the list specified by the CONFIGURE_FILE
3523 compile-time setting. Usually, the list will consist of just a single filename,
3524 but it can be a colon-separated list of names. In this case, the first
3525 file that exists is used. Failure to open an existing file stops Exim from
3526 proceeding any further along the list, and an error is generated.
3528 When this option is used by a caller other than root, and the list is different
3529 from the compiled-in list, Exim gives up its root privilege immediately, and
3530 runs with the real and effective uid and gid set to those of the caller.
3531 However, if a TRUSTED_CONFIG_LIST file is defined in &_Local/Makefile_&, that
3532 file contains a list of full pathnames, one per line, for configuration files
3533 which are trusted. Root privilege is retained for any configuration file so
3534 listed, as long as the caller is the Exim user (or the user specified in the
3535 CONFIGURE_OWNER option, if any), and as long as the configuration file is
3536 not writeable by inappropriate users or groups.
3538 Leaving TRUSTED_CONFIG_LIST unset precludes the possibility of testing a
3539 configuration using &%-C%& right through message reception and delivery,
3540 even if the caller is root. The reception works, but by that time, Exim is
3541 running as the Exim user, so when it re-executes to regain privilege for the
3542 delivery, the use of &%-C%& causes privilege to be lost. However, root can
3543 test reception and delivery using two separate commands (one to put a message
3544 in the queue, using &%-odq%&, and another to do the delivery, using &%-M%&).
3546 If ALT_CONFIG_PREFIX is defined &_in Local/Makefile_&, it specifies a
3547 prefix string with which any file named in a &%-C%& command line option
3548 must start. In addition, the filename must not contain the sequence &`/../`&.
3549 However, if the value of the &%-C%& option is identical to the value of
3550 CONFIGURE_FILE in &_Local/Makefile_&, Exim ignores &%-C%& and proceeds as
3551 usual. There is no default setting for ALT_CONFIG_PREFIX; when it is
3552 unset, any filename can be used with &%-C%&.
3554 ALT_CONFIG_PREFIX can be used to confine alternative configuration files
3555 to a directory to which only root has access. This prevents someone who has
3556 broken into the Exim account from running a privileged Exim with an arbitrary
3557 configuration file.
3559 The &%-C%& facility is useful for ensuring that configuration files are
3560 syntactically correct, but cannot be used for test deliveries, unless the
3561 caller is privileged, or unless it is an exotic configuration that does not
3562 require privilege. No check is made on the owner or group of the files
3563 specified by this option.
3566 .vitem &%-D%&<&'macro'&>=<&'value'&>
3567 .oindex "&%-D%&"
3568 .cindex "macro" "setting on command line"
3569 This option can be used to override macro definitions in the configuration file
3570 (see section &<<SECTmacrodefs>>&). However, like &%-C%&, if it is used by an
3571 unprivileged caller, it causes Exim to give up its root privilege.
3572 If DISABLE_D_OPTION is defined in &_Local/Makefile_&, the use of &%-D%& is
3573 completely disabled, and its use causes an immediate error exit.
3575 If WHITELIST_D_MACROS is defined in &_Local/Makefile_& then it should be a
3576 colon-separated list of macros which are considered safe and, if &%-D%& only
3577 supplies macros from this list, and the values are acceptable, then Exim will
3578 not give up root privilege if the caller is root, the Exim run-time user, or
3579 the CONFIGURE_OWNER, if set. This is a transition mechanism and is expected
3580 to be removed in the future. Acceptable values for the macros satisfy the
3581 regexp: &`^[A-Za-z0-9_/.-]*$`&
3583 The entire option (including equals sign if present) must all be within one
3584 command line item. &%-D%& can be used to set the value of a macro to the empty
3585 string, in which case the equals sign is optional. These two commands are
3586 synonymous:
3587 .code
3588 exim -DABC ...
3589 exim -DABC= ...
3590 .endd
3591 To include spaces in a macro definition item, quotes must be used. If you use
3592 quotes, spaces are permitted around the macro name and the equals sign. For
3593 example:
3594 .code
3595 exim '-D ABC = something' ...
3596 .endd
3597 &%-D%& may be repeated up to 10 times on a command line.
3598 Only macro names up to 22 letters long can be set.
3601 .vitem &%-d%&<&'debug&~options'&>
3602 .oindex "&%-d%&"
3603 .cindex "debugging" "list of selectors"
3604 .cindex "debugging" "&%-d%& option"
3605 This option causes debugging information to be written to the standard
3606 error stream. It is restricted to admin users because debugging output may show
3607 database queries that contain password information. Also, the details of users'
3608 filter files should be protected. If a non-admin user uses &%-d%&, Exim
3609 writes an error message to the standard error stream and exits with a non-zero
3610 return code.
3612 When &%-d%& is used, &%-v%& is assumed. If &%-d%& is given on its own, a lot of
3613 standard debugging data is output. This can be reduced, or increased to include
3614 some more rarely needed information, by directly following &%-d%& with a string
3615 made up of names preceded by plus or minus characters. These add or remove sets
3616 of debugging data, respectively. For example, &%-d+filter%& adds filter
3617 debugging, whereas &%-d-all+filter%& selects only filter debugging. Note that
3618 no spaces are allowed in the debug setting. The available debugging categories
3619 are:
3620 .display
3621 &`acl `& ACL interpretation
3622 &`auth `& authenticators
3623 &`deliver `& general delivery logic
3624 &`dns `& DNS lookups (see also resolver)
3625 &`dnsbl `& DNS black list (aka RBL) code
3626 &`exec `& arguments for &[execv()]& calls
3627 &`expand `& detailed debugging for string expansions
3628 &`filter `& filter handling
3629 &`hints_lookup `& hints data lookups
3630 &`host_lookup `& all types of name-to-IP address handling
3631 &`ident `& ident lookup
3632 &`interface `& lists of local interfaces
3633 &`lists `& matching things in lists
3634 &`load `& system load checks
3635 &`local_scan `& can be used by &[local_scan()]& (see chapter &&&
3636 &<<CHAPlocalscan>>&)
3637 &`lookup `& general lookup code and all lookups
3638 &`memory `& memory handling
3639 &`noutf8 `& modifier: avoid UTF-8 line-drawing
3640 &`pid `& modifier: add pid to debug output lines
3641 &`process_info `& setting info for the process log
3642 &`queue_run `& queue runs
3643 &`receive `& general message reception logic
3644 &`resolver `& turn on the DNS resolver's debugging output
3645 &`retry `& retry handling
3646 &`rewrite `& address rewriting
3647 &`route `& address routing
3648 &`timestamp `& modifier: add timestamp to debug output lines
3649 &`tls `& TLS logic
3650 &`transport `& transports
3651 &`uid `& changes of uid/gid and looking up uid/gid
3652 &`verify `& address verification logic
3653 &`all `& almost all of the above (see below), and also &%-v%&
3654 .endd
3655 The &`all`& option excludes &`memory`& when used as &`+all`&, but includes it
3656 for &`-all`&. The reason for this is that &`+all`& is something that people
3657 tend to use when generating debug output for Exim maintainers. If &`+memory`&
3658 is included, an awful lot of output that is very rarely of interest is
3659 generated, so it now has to be explicitly requested. However, &`-all`& does
3660 turn everything off.
3662 .cindex "resolver, debugging output"
3663 .cindex "DNS resolver, debugging output"
3664 The &`resolver`& option produces output only if the DNS resolver was compiled
3665 with DEBUG enabled. This is not the case in some operating systems. Also,
3666 unfortunately, debugging output from the DNS resolver is written to stdout
3667 rather than stderr.
3669 The default (&%-d%& with no argument) omits &`expand`&, &`filter`&,
3670 &`interface`&, &`load`&, &`memory`&, &`pid`&, &`resolver`&, and &`timestamp`&.
3671 However, the &`pid`& selector is forced when debugging is turned on for a
3672 daemon, which then passes it on to any re-executed Exims. Exim also
3673 automatically adds the pid to debug lines when several remote deliveries are
3674 run in parallel.
3676 The &`timestamp`& selector causes the current time to be inserted at the start
3677 of all debug output lines. This can be useful when trying to track down delays
3678 in processing.
3680 .cindex debugging "UTF-8 in"
3681 .cindex UTF-8 "in debug output"
3682 The &`noutf8`& selector disables the use of
3683 UTF-8 line-drawing characters to group related information.
3684 When disabled. ascii-art is used instead.
3685 Using the &`+all`& option does not set this modifier,
3687 If the &%debug_print%& option is set in any driver, it produces output whenever
3688 any debugging is selected, or if &%-v%& is used.
3690 .vitem &%-dd%&<&'debug&~options'&>
3691 .oindex "&%-dd%&"
3692 This option behaves exactly like &%-d%& except when used on a command that
3693 starts a daemon process. In that case, debugging is turned off for the
3694 subprocesses that the daemon creates. Thus, it is useful for monitoring the
3695 behaviour of the daemon without creating as much output as full debugging does.
3697 .vitem &%-dropcr%&
3698 .oindex "&%-dropcr%&"
3699 This is an obsolete option that is now a no-op. It used to affect the way Exim
3700 handled CR and LF characters in incoming messages. What happens now is
3701 described in section &<<SECTlineendings>>&.
3703 .vitem &%-E%&
3704 .oindex "&%-E%&"
3705 .cindex "bounce message" "generating"
3706 This option specifies that an incoming message is a locally-generated delivery
3707 failure report. It is used internally by Exim when handling delivery failures
3708 and is not intended for external use. Its only effect is to stop Exim
3709 generating certain messages to the postmaster, as otherwise message cascades
3710 could occur in some situations. As part of the same option, a message id may
3711 follow the characters &%-E%&. If it does, the log entry for the receipt of the
3712 new message contains the id, following &"R="&, as a cross-reference.
3714 .vitem &%-e%&&'x'&
3715 .oindex "&%-e%&&'x'&"
3716 There are a number of Sendmail options starting with &%-oe%& which seem to be
3717 called by various programs without the leading &%o%& in the option. For
3718 example, the &%vacation%& program uses &%-eq%&. Exim treats all options of the
3719 form &%-e%&&'x'& as synonymous with the corresponding &%-oe%&&'x'& options.
3721 .vitem &%-F%&&~<&'string'&>
3722 .oindex "&%-F%&"
3723 .cindex "sender" "name"
3724 .cindex "name" "of sender"
3725 This option sets the sender's full name for use when a locally-generated
3726 message is being accepted. In the absence of this option, the user's &'gecos'&
3727 entry from the password data is used. As users are generally permitted to alter
3728 their &'gecos'& entries, no security considerations are involved. White space
3729 between &%-F%& and the <&'string'&> is optional.
3731 .vitem &%-f%&&~<&'address'&>
3732 .oindex "&%-f%&"
3733 .cindex "sender" "address"
3734 .cindex "address" "sender"
3735 .cindex "trusted users"
3736 .cindex "envelope from"
3737 .cindex "envelope sender"
3738 .cindex "user" "trusted"
3739 This option sets the address of the envelope sender of a locally-generated
3740 message (also known as the return path). The option can normally be used only
3741 by a trusted user, but &%untrusted_set_sender%& can be set to allow untrusted
3742 users to use it.
3744 Processes running as root or the Exim user are always trusted. Other
3745 trusted users are defined by the &%trusted_users%& or &%trusted_groups%&
3746 options. In the absence of &%-f%&, or if the caller is not trusted, the sender
3747 of a local message is set to the caller's login name at the default qualify
3748 domain.
3750 There is one exception to the restriction on the use of &%-f%&: an empty sender
3751 can be specified by any user, trusted or not, to create a message that can
3752 never provoke a bounce. An empty sender can be specified either as an empty
3753 string, or as a pair of angle brackets with nothing between them, as in these
3754 examples of shell commands:
3755 .code
3756 exim -f '<>' user@domain
3757 exim -f "" user@domain
3758 .endd
3759 In addition, the use of &%-f%& is not restricted when testing a filter file
3760 with &%-bf%& or when testing or verifying addresses using the &%-bt%& or
3761 &%-bv%& options.
3763 Allowing untrusted users to change the sender address does not of itself make
3764 it possible to send anonymous mail. Exim still checks that the &'From:'& header
3765 refers to the local user, and if it does not, it adds a &'Sender:'& header,
3766 though this can be overridden by setting &%no_local_from_check%&.
3768 White
3769 .cindex "&""From""& line"
3770 space between &%-f%& and the <&'address'&> is optional (that is, they can be
3771 given as two arguments or one combined argument). The sender of a
3772 locally-generated message can also be set (when permitted) by an initial
3773 &"From&~"& line in the message &-- see the description of &%-bm%& above &-- but
3774 if &%-f%& is also present, it overrides &"From&~"&.
3776 .vitem &%-G%&
3777 .oindex "&%-G%&"
3778 .cindex "submission fixups, suppressing (command-line)"
3779 This option is equivalent to an ACL applying:
3780 .code
3781 control = suppress_local_fixups
3782 .endd
3783 for every message received. Note that Sendmail will complain about such
3784 bad formatting, where Exim silently just does not fix it up. This may change
3785 in future.
3787 As this affects audit information, the caller must be a trusted user to use
3788 this option.
3790 .vitem &%-h%&&~<&'number'&>
3791 .oindex "&%-h%&"
3792 .cindex "Sendmail compatibility" "&%-h%& option ignored"
3793 This option is accepted for compatibility with Sendmail, but has no effect. (In
3794 Sendmail it overrides the &"hop count"& obtained by counting &'Received:'&
3795 headers.)
3797 .vitem &%-i%&
3798 .oindex "&%-i%&"
3799 .cindex "Solaris" "&'mail'& command"
3800 .cindex "dot" "in incoming non-SMTP message"
3801 This option, which has the same effect as &%-oi%&, specifies that a dot on a
3802 line by itself should not terminate an incoming, non-SMTP message. I can find
3803 no documentation for this option in Solaris 2.4 Sendmail, but the &'mailx'&
3804 command in Solaris 2.4 uses it. See also &%-ti%&.
3806 .vitem &%-L%&&~<&'tag'&>
3807 .oindex "&%-L%&"
3808 .cindex "syslog" "process name; set with flag"
3809 This option is equivalent to setting &%syslog_processname%& in the config
3810 file and setting &%log_file_path%& to &`syslog`&.
3811 Its use is restricted to administrators. The configuration file has to be
3812 read and parsed, to determine access rights, before this is set and takes
3813 effect, so early configuration file errors will not honour this flag.
3815 The tag should not be longer than 32 characters.
3817 .vitem &%-M%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3818 .oindex "&%-M%&"
3819 .cindex "forcing delivery"
3820 .cindex "delivery" "forcing attempt"
3821 .cindex "frozen messages" "forcing delivery"
3822 This option requests Exim to run a delivery attempt on each message in turn. If
3823 any of the messages are frozen, they are automatically thawed before the
3824 delivery attempt. The settings of &%queue_domains%&, &%queue_smtp_domains%&,
3825 and &%hold_domains%& are ignored.
3827 Retry
3828 .cindex "hints database" "overriding retry hints"
3829 hints for any of the addresses are overridden &-- Exim tries to deliver even if
3830 the normal retry time has not yet been reached. This option requires the caller
3831 to be an admin user. However, there is an option called &%prod_requires_admin%&
3832 which can be set false to relax this restriction (and also the same requirement
3833 for the &%-q%&, &%-R%&, and &%-S%& options).
3835 The deliveries happen synchronously, that is, the original Exim process does
3836 not terminate until all the delivery attempts have finished. No output is
3837 produced unless there is a serious error. If you want to see what is happening,
3838 use the &%-v%& option as well, or inspect Exim's main log.
3840 .vitem &%-Mar%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
3841 .oindex "&%-Mar%&"
3842 .cindex "message" "adding recipients"
3843 .cindex "recipient" "adding"
3844 This option requests Exim to add the addresses to the list of recipients of the
3845 message (&"ar"& for &"add recipients"&). The first argument must be a message
3846 id, and the remaining ones must be email addresses. However, if the message is
3847 active (in the middle of a delivery attempt), it is not altered. This option
3848 can be used only by an admin user.
3850 .vitem "&%-MC%&&~<&'transport'&>&~<&'hostname'&>&~<&'sequence&~number'&>&&&
3851 &~<&'message&~id'&>"
3852 .oindex "&%-MC%&"
3853 .cindex "SMTP" "passed connection"
3854 .cindex "SMTP" "multiple deliveries"
3855 .cindex "multiple SMTP deliveries"
3856 This option is not intended for use by external callers. It is used internally
3857 by Exim to invoke another instance of itself to deliver a waiting message using
3858 an existing SMTP connection, which is passed as the standard input. Details are
3859 given in chapter &<<CHAPSMTP>>&. This must be the final option, and the caller
3860 must be root or the Exim user in order to use it.
3862 .vitem &%-MCA%&
3863 .oindex "&%-MCA%&"
3864 This option is not intended for use by external callers. It is used internally
3865 by Exim in conjunction with the &%-MC%& option. It signifies that the
3866 connection to the remote host has been authenticated.
3868 .vitem &%-MCD%&
3869 .oindex "&%-MCD%&"
3870 This option is not intended for use by external callers. It is used internally
3871 by Exim in conjunction with the &%-MC%& option. It signifies that the
3872 remote host supports the ESMTP &_DSN_& extension.
3874 .new
3875 .vitem &%-MCd%&
3876 .oindex "&%-MCd%&"
3877 This option is not intended for use by external callers. It is used internally
3878 by Exim in conjunction with the &%-d%& option
3879 to pass on an information string on the purpose of the process.
3880 .wen
3882 .vitem &%-MCG%&&~<&'queue&~name'&>
3883 .oindex "&%-MCG%&"
3884 This option is not intended for use by external callers. It is used internally
3885 by Exim in conjunction with the &%-MC%& option. It signifies that an
3886 alternate queue is used, named by the following argument.
3888 .vitem &%-MCK%&
3889 .oindex "&%-MCK%&"
3890 This option is not intended for use by external callers. It is used internally
3891 by Exim in conjunction with the &%-MC%& option. It signifies that a
3892 remote host supports the ESMTP &_CHUNKING_& extension.
3894 .vitem &%-MCP%&
3895 .oindex "&%-MCP%&"
3896 This option is not intended for use by external callers. It is used internally
3897 by Exim in conjunction with the &%-MC%& option. It signifies that the server to
3898 which Exim is connected supports pipelining.
3900 .vitem &%-MCQ%&&~<&'process&~id'&>&~<&'pipe&~fd'&>
3901 .oindex "&%-MCQ%&"
3902 This option is not intended for use by external callers. It is used internally
3903 by Exim in conjunction with the &%-MC%& option when the original delivery was
3904 started by a queue runner. It passes on the process id of the queue runner,
3905 together with the file descriptor number of an open pipe. Closure of the pipe
3906 signals the final completion of the sequence of processes that are passing
3907 messages through the same SMTP connection.
3909 .vitem &%-MCS%&
3910 .oindex "&%-MCS%&"
3911 This option is not intended for use by external callers. It is used internally
3912 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3913 SMTP SIZE option should be used on messages delivered down the existing
3914 connection.
3916 .vitem &%-MCT%&
3917 .oindex "&%-MCT%&"
3918 This option is not intended for use by external callers. It is used internally
3919 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3920 host to which Exim is connected supports TLS encryption.
3922 .vitem &%-MCt%&&~<&'IP&~address'&>&~<&'port'&>&~<&'cipher'&>
3923 .oindex "&%-MCt%&"
3924 This option is not intended for use by external callers. It is used internally
3925 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3926 connection is being proxied by a parent process for handling TLS encryption.
3927 The arguments give the local address and port being proxied, and the TLS cipher.
3929 .vitem &%-Mc%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3930 .oindex "&%-Mc%&"
3931 .cindex "hints database" "not overridden by &%-Mc%&"
3932 .cindex "delivery" "manually started &-- not forced"
3933 This option requests Exim to run a delivery attempt on each message, in turn,
3934 but unlike the &%-M%& option, it does check for retry hints, and respects any
3935 that are found. This option is not very useful to external callers. It is
3936 provided mainly for internal use by Exim when it needs to re-invoke itself in
3937 order to regain root privilege for a delivery (see chapter &<<CHAPsecurity>>&).
3938 However, &%-Mc%& can be useful when testing, in order to run a delivery that
3939 respects retry times and other options such as &%hold_domains%& that are
3940 overridden when &%-M%& is used. Such a delivery does not count as a queue run.
3941 If you want to run a specific delivery as if in a queue run, you should use
3942 &%-q%& with a message id argument. A distinction between queue run deliveries
3943 and other deliveries is made in one or two places.
3945 .vitem &%-Mes%&&~<&'message&~id'&>&~<&'address'&>
3946 .oindex "&%-Mes%&"
3947 .cindex "message" "changing sender"
3948 .cindex "sender" "changing"
3949 This option requests Exim to change the sender address in the message to the
3950 given address, which must be a fully qualified address or &"<>"& (&"es"& for
3951 &"edit sender"&). There must be exactly two arguments. The first argument must
3952 be a message id, and the second one an email address. However, if the message
3953 is active (in the middle of a delivery attempt), its status is not altered.
3954 This option can be used only by an admin user.
3956 .vitem &%-Mf%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3957 .oindex "&%-Mf%&"
3958 .cindex "freezing messages"
3959 .cindex "message" "manually freezing"
3960 This option requests Exim to mark each listed message as &"frozen"&. This
3961 prevents any delivery attempts taking place until the message is &"thawed"&,
3962 either manually or as a result of the &%auto_thaw%& configuration option.
3963 However, if any of the messages are active (in the middle of a delivery
3964 attempt), their status is not altered. This option can be used only by an admin
3965 user.
3967 .vitem &%-Mg%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3968 .oindex "&%-Mg%&"
3969 .cindex "giving up on messages"
3970 .cindex "message" "abandoning delivery attempts"
3971 .cindex "delivery" "abandoning further attempts"
3972 This option requests Exim to give up trying to deliver the listed messages,
3973 including any that are frozen. However, if any of the messages are active,
3974 their status is not altered. For non-bounce messages, a delivery error message
3975 is sent to the sender, containing the text &"cancelled by administrator"&.
3976 Bounce messages are just discarded. This option can be used only by an admin
3977 user.
3979 .vitem &%-MG%&&~<&'queue&~name'&>&~<&'message&~id'&>&~<&'message&~id'&>&~...
3980 .oindex "&%-MG%&"
3981 .cindex queue named
3982 .cindex "named queues" "moving messages"
3983 .cindex "queue" "moving messages"
3984 This option requests that each listed message be moved from its current
3985 queue to the given named queue.
3986 The destination queue name argument is required, but can be an empty
3987 string to define the default queue.
3988 If the messages are not currently located in the default queue,
3989 a &%-qG<name>%& option will be required to define the source queue.
3991 .vitem &%-Mmad%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3992 .oindex "&%-Mmad%&"
3993 .cindex "delivery" "cancelling all"
3994 This option requests Exim to mark all the recipient addresses in the messages
3995 as already delivered (&"mad"& for &"mark all delivered"&). However, if any
3996 message is active (in the middle of a delivery attempt), its status is not
3997 altered. This option can be used only by an admin user.
3999 .vitem &%-Mmd%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
4000 .oindex "&%-Mmd%&"
4001 .cindex "delivery" "cancelling by address"
4002 .cindex "recipient" "removing"
4003 .cindex "removing recipients"
4004 This option requests Exim to mark the given addresses as already delivered
4005 (&"md"& for &"mark delivered"&). The first argument must be a message id, and
4006 the remaining ones must be email addresses. These are matched to recipient
4007 addresses in the message in a case-sensitive manner. If the message is active
4008 (in the middle of a delivery attempt), its status is not altered. This option
4009 can be used only by an admin user.
4011 .vitem &%-Mrm%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
4012 .oindex "&%-Mrm%&"
4013 .cindex "removing messages"
4014 .cindex "abandoning mail"
4015 .cindex "message" "manually discarding"
4016 This option requests Exim to remove the given messages from the queue. No
4017 bounce messages are sent; each message is simply forgotten. However, if any of
4018 the messages are active, their status is not altered. This option can be used
4019 only by an admin user or by the user who originally caused the message to be
4020 placed in the queue.
4022 . .new
4023 . .vitem &%-MS%&
4024 . .oindex "&%-MS%&"
4025 . .cindex REQUIRETLS
4026 . This option is used to request REQUIRETLS processing on the message.
4027 . It is used internally by Exim in conjunction with -E when generating
4028 . a bounce message.
4029 . .wen
4031 .vitem &%-Mset%&&~<&'message&~id'&>
4032 .oindex "&%-Mset%&"
4033 .cindex "testing" "string expansion"
4034 .cindex "expansion" "testing"
4035 This option is useful only in conjunction with &%-be%& (that is, when testing
4036 string expansions). Exim loads the given message from its spool before doing
4037 the test expansions, thus setting message-specific variables such as
4038 &$message_size$& and the header variables. The &$recipients$& variable is made
4039 available. This feature is provided to make it easier to test expansions that
4040 make use of these variables. However, this option can be used only by an admin
4041 user. See also &%-bem%&.
4043 .vitem &%-Mt%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
4044 .oindex "&%-Mt%&"
4045 .cindex "thawing messages"
4046 .cindex "unfreezing messages"
4047 .cindex "frozen messages" "thawing"
4048 .cindex "message" "thawing frozen"
4049 This option requests Exim to &"thaw"& any of the listed messages that are
4050 &"frozen"&, so that delivery attempts can resume. However, if any of the
4051 messages are active, their status is not altered. This option can be used only
4052 by an admin user.
4054 .vitem &%-Mvb%&&~<&'message&~id'&>
4055 .oindex "&%-Mvb%&"
4056 .cindex "listing" "message body"
4057 .cindex "message" "listing body of"
4058 This option causes the contents of the message body (-D) spool file to be
4059 written to the standard output. This option can be used only by an admin user.
4061 .vitem &%-Mvc%&&~<&'message&~id'&>
4062 .oindex "&%-Mvc%&"
4063 .cindex "message" "listing in RFC 2822 format"
4064 .cindex "listing" "message in RFC 2822 format"
4065 This option causes a copy of the complete message (header lines plus body) to
4066 be written to the standard output in RFC 2822 format. This option can be used
4067 only by an admin user.
4069 .vitem &%-Mvh%&&~<&'message&~id'&>
4070 .oindex "&%-Mvh%&"
4071 .cindex "listing" "message headers"
4072 .cindex "header lines" "listing"
4073 .cindex "message" "listing header lines"
4074 This option causes the contents of the message headers (-H) spool file to be
4075 written to the standard output. This option can be used only by an admin user.
4077 .vitem &%-Mvl%&&~<&'message&~id'&>
4078 .oindex "&%-Mvl%&"
4079 .cindex "listing" "message log"
4080 .cindex "message" "listing message log"
4081 This option causes the contents of the message log spool file to be written to
4082 the standard output. This option can be used only by an admin user.
4084 .vitem &%-m%&
4085 .oindex "&%-m%&"
4086 This is apparently a synonym for &%-om%& that is accepted by Sendmail, so Exim
4087 treats it that way too.
4089 .vitem &%-N%&
4090 .oindex "&%-N%&"
4091 .cindex "debugging" "&%-N%& option"
4092 .cindex "debugging" "suppressing delivery"
4093 This is a debugging option that inhibits delivery of a message at the transport
4094 level. It implies &%-v%&. Exim goes through many of the motions of delivery &--
4095 it just doesn't actually transport the message, but instead behaves as if it
4096 had successfully done so. However, it does not make any updates to the retry
4097 database, and the log entries for deliveries are flagged with &"*>"& rather
4098 than &"=>"&.
4100 Because &%-N%& discards any message to which it applies, only root or the Exim
4101 user are allowed to use it with &%-bd%&, &%-q%&, &%-R%& or &%-M%&. In other
4102 words, an ordinary user can use it only when supplying an incoming message to
4103 which it will apply. Although transportation never fails when &%-N%& is set, an
4104 address may be deferred because of a configuration problem on a transport, or a
4105 routing problem. Once &%-N%& has been used for a delivery attempt, it sticks to
4106 the message, and applies to any subsequent delivery attempts that may happen
4107 for that message.
4109 .vitem &%-n%&
4110 .oindex "&%-n%&"
4111 This option is interpreted by Sendmail to mean &"no aliasing"&.
4112 For normal modes of operation, it is ignored by Exim.
4113 When combined with &%-bP%& it makes the output more terse (suppresses
4114 option names, environment values and config pretty printing).
4116 .vitem &%-O%&&~<&'data'&>
4117 .oindex "&%-O%&"
4118 This option is interpreted by Sendmail to mean &`set option`&. It is ignored by
4119 Exim.
4121 .vitem &%-oA%&&~<&'file&~name'&>
4122 .oindex "&%-oA%&"
4123 .cindex "Sendmail compatibility" "&%-oA%& option"
4124 This option is used by Sendmail in conjunction with &%-bi%& to specify an
4125 alternative alias filename. Exim handles &%-bi%& differently; see the
4126 description above.
4128 .vitem &%-oB%&&~<&'n'&>
4129 .oindex "&%-oB%&"
4130 .cindex "SMTP" "passed connection"
4131 .cindex "SMTP" "multiple deliveries"
4132 .cindex "multiple SMTP deliveries"
4133 This is a debugging option which limits the maximum number of messages that can
4134 be delivered down one SMTP connection, overriding the value set in any &(smtp)&
4135 transport. If <&'n'&> is omitted, the limit is set to 1.
4137 .vitem &%-odb%&
4138 .oindex "&%-odb%&"
4139 .cindex "background delivery"
4140 .cindex "delivery" "in the background"
4141 This option applies to all modes in which Exim accepts incoming messages,
4142 including the listening daemon. It requests &"background"& delivery of such
4143 messages, which means that the accepting process automatically starts a
4144 delivery process for each message received, but does not wait for the delivery
4145 processes to finish.
4147 When all the messages have been received, the reception process exits,
4148 leaving the delivery processes to finish in their own time. The standard output
4149 and error streams are closed at the start of each delivery process.
4150 This is the default action if none of the &%-od%& options are present.
4152 If one of the queueing options in the configuration file
4153 (&%queue_only%& or &%queue_only_file%&, for example) is in effect, &%-odb%&
4154 overrides it if &%queue_only_override%& is set true, which is the default
4155 setting. If &%queue_only_override%& is set false, &%-odb%& has no effect.
4157 .vitem &%-odf%&
4158 .oindex "&%-odf%&"
4159 .cindex "foreground delivery"
4160 .cindex "delivery" "in the foreground"
4161 This option requests &"foreground"& (synchronous) delivery when Exim has
4162 accepted a locally-generated message. (For the daemon it is exactly the same as
4163 &%-odb%&.) A delivery process is automatically started to deliver the message,
4164 and Exim waits for it to complete before proceeding.
4166 The original Exim reception process does not finish until the delivery
4167 process for the final message has ended. The standard error stream is left open
4168 during deliveries.
4170 However, like &%-odb%&, this option has no effect if &%queue_only_override%& is
4171 false and one of the queueing options in the configuration file is in effect.
4173 If there is a temporary delivery error during foreground delivery, the
4174 message is left in the queue for later delivery, and the original reception
4175 process exits. See chapter &<<CHAPnonqueueing>>& for a way of setting up a
4176 restricted configuration that never queues messages.
4179 .vitem &%-odi%&
4180 .oindex "&%-odi%&"
4181 This option is synonymous with &%-odf%&. It is provided for compatibility with
4182 Sendmail.
4184 .vitem &%-odq%&
4185 .oindex "&%-odq%&"
4186 .cindex "non-immediate delivery"
4187 .cindex "delivery" "suppressing immediate"
4188 .cindex "queueing incoming messages"
4189 This option applies to all modes in which Exim accepts incoming messages,
4190 including the listening daemon. It specifies that the accepting process should
4191 not automatically start a delivery process for each message received. Messages
4192 are placed in the queue, and remain there until a subsequent queue runner
4193 process encounters them. There are several configuration options (such as
4194 &%queue_only%&) that can be used to queue incoming messages under certain
4195 conditions. This option overrides all of them and also &%-odqs%&. It always
4196 forces queueing.
4198 .vitem &%-odqs%&
4199 .oindex "&%-odqs%&"
4200 .cindex "SMTP" "delaying delivery"
4201 .cindex "first pass routing"
4202 This option is a hybrid between &%-odb%&/&%-odi%& and &%-odq%&.
4203 However, like &%-odb%& and &%-odi%&, this option has no effect if
4204 &%queue_only_override%& is false and one of the queueing options in the
4205 configuration file is in effect.
4207 When &%-odqs%& does operate, a delivery process is started for each incoming
4208 message, in the background by default, but in the foreground if &%-odi%& is
4209 also present. The recipient addresses are routed, and local deliveries are done
4210 in the normal way. However, if any SMTP deliveries are required, they are not
4211 done at this time, so the message remains in the queue until a subsequent queue
4212 runner process encounters it. Because routing was done, Exim knows which
4213 messages are waiting for which hosts, and so a number of messages for the same
4214 host can be sent in a single SMTP connection. The &%queue_smtp_domains%&
4215 configuration option has the same effect for specific domains. See also the
4216 &%-qq%& option.
4218 .vitem &%-oee%&
4219 .oindex "&%-oee%&"
4220 .cindex "error" "reporting"
4221 If an error is detected while a non-SMTP message is being received (for
4222 example, a malformed address), the error is reported to the sender in a mail
4223 message.
4225 .cindex "return code" "for &%-oee%&"
4226 Provided
4227 this error message is successfully sent, the Exim receiving process
4228 exits with a return code of zero. If not, the return code is 2 if the problem
4229 is that the original message has no recipients, or 1 for any other error.
4230 This is the default &%-oe%&&'x'& option if Exim is called as &'rmail'&.
4232 .vitem &%-oem%&
4233 .oindex "&%-oem%&"
4234 .cindex "error" "reporting"
4235 .cindex "return code" "for &%-oem%&"
4236 This is the same as &%-oee%&, except that Exim always exits with a non-zero
4237 return code, whether or not the error message was successfully sent.
4238 This is the default &%-oe%&&'x'& option, unless Exim is called as &'rmail'&.
4240 .vitem &%-oep%&
4241 .oindex "&%-oep%&"
4242 .cindex "error" "reporting"
4243 If an error is detected while a non-SMTP message is being received, the
4244 error is reported by writing a message to the standard error file (stderr).
4245 .cindex "return code" "for &%-oep%&"
4246 The return code is 1 for all errors.
4248 .vitem &%-oeq%&
4249 .oindex "&%-oeq%&"
4250 .cindex "error" "reporting"
4251 This option is supported for compatibility with Sendmail, but has the same
4252 effect as &%-oep%&.
4254 .vitem &%-oew%&
4255 .oindex "&%-oew%&"
4256 .cindex "error" "reporting"
4257 This option is supported for compatibility with Sendmail, but has the same
4258 effect as &%-oem%&.
4260 .vitem &%-oi%&
4261 .oindex "&%-oi%&"
4262 .cindex "dot" "in incoming non-SMTP message"
4263 This option, which has the same effect as &%-i%&, specifies that a dot on a
4264 line by itself should not terminate an incoming, non-SMTP message. Otherwise, a
4265 single dot does terminate, though Exim does no special processing for other
4266 lines that start with a dot. This option is set by default if Exim is called as
4267 &'rmail'&. See also &%-ti%&.
4269 .vitem &%-oitrue%&
4270 .oindex "&%-oitrue%&"
4271 This option is treated as synonymous with &%-oi%&.
4273 .vitem &%-oMa%&&~<&'host&~address'&>
4274 .oindex "&%-oMa%&"
4275 .cindex "sender" "host address, specifying for local message"
4276 A number of options starting with &%-oM%& can be used to set values associated
4277 with remote hosts on locally-submitted messages (that is, messages not received
4278 over TCP/IP). These options can be used by any caller in conjunction with the
4279 &%-bh%&, &%-be%&, &%-bf%&, &%-bF%&, &%-bt%&, or &%-bv%& testing options. In
4280 other circumstances, they are ignored unless the caller is trusted.
4282 The &%-oMa%& option sets the sender host address. This may include a port
4283 number at the end, after a full stop (period). For example:
4284 .code
4285 exim -bs -oMa
4286 .endd
4287 An alternative syntax is to enclose the IP address in square brackets,
4288 followed by a colon and the port number:
4289 .code
4290 exim -bs -oMa []:1234
4291 .endd
4292 The IP address is placed in the &$sender_host_address$& variable, and the
4293 port, if present, in &$sender_host_port$&. If both &%-oMa%& and &%-bh%&
4294 are present on the command line, the sender host IP address is taken from
4295 whichever one is last.
4297 .vitem &%-oMaa%&&~<&'name'&>
4298 .oindex "&%-oMaa%&"
4299 .cindex "authentication" "name, specifying for local message"
4300 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMaa%&
4301 option sets the value of &$sender_host_authenticated$& (the authenticator
4302 name). See chapter &<<CHAPSMTPAUTH>>& for a discussion of SMTP authentication.
4303 This option can be used with &%-bh%& and &%-bs%& to set up an
4304 authenticated SMTP session without actually using the SMTP AUTH command.
4306 .vitem &%-oMai%&&~<&'string'&>
4307 .oindex "&%-oMai%&"
4308 .cindex "authentication" "id, specifying for local message"
4309 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMai%&
4310 option sets the value of &$authenticated_id$& (the id that was authenticated).
4311 This overrides the default value (the caller's login id, except with &%-bh%&,
4312 where there is no default) for messages from local sources. See chapter
4313 &<<CHAPSMTPAUTH>>& for a discussion of authenticated ids.
4315 .vitem &%-oMas%&&~<&'address'&>
4316 .oindex "&%-oMas%&"
4317 .cindex "authentication" "sender, specifying for local message"
4318 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMas%&
4319 option sets the authenticated sender value in &$authenticated_sender$&. It
4320 overrides the sender address that is created from the caller's login id for
4321 messages from local sources, except when &%-bh%& is used, when there is no
4322 default. For both &%-bh%& and &%-bs%&, an authenticated sender that is
4323 specified on a MAIL command overrides this value. See chapter
4324 &<<CHAPSMTPAUTH>>& for a discussion of authenticated senders.
4326 .vitem &%-oMi%&&~<&'interface&~address'&>
4327 .oindex "&%-oMi%&"
4328 .cindex "interface" "address, specifying for local message"
4329 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMi%&
4330 option sets the IP interface address value. A port number may be included,
4331 using the same syntax as for &%-oMa%&. The interface address is placed in
4332 &$received_ip_address$& and the port number, if present, in &$received_port$&.
4334 .vitem &%-oMm%&&~<&'message&~reference'&>
4335 .oindex "&%-oMm%&"
4336 .cindex "message reference" "message reference, specifying for local message"
4337 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMm%&
4338 option sets the message reference, e.g. message-id, and is logged during
4339 delivery. This is useful when some kind of audit trail is required to tie
4340 messages together. The format of the message reference is checked and will
4341 abort if the format is invalid. The option will only be accepted if exim is
4342 running in trusted mode, not as any regular user.
4344 The best example of a message reference is when Exim sends a bounce message.
4345 The message reference is the message-id of the original message for which Exim
4346 is sending the bounce.
4348 .vitem &%-oMr%&&~<&'protocol&~name'&>
4349 .oindex "&%-oMr%&"
4350 .cindex "protocol, specifying for local message"
4351 .vindex "&$received_protocol$&"
4352 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMr%&
4353 option sets the received protocol value that is stored in
4354 &$received_protocol$&. However, it does not apply (and is ignored) when &%-bh%&
4355 or &%-bs%& is used. For &%-bh%&, the protocol is forced to one of the standard
4356 SMTP protocol names (see the description of &$received_protocol$& in section
4357 &<<SECTexpvar>>&). For &%-bs%&, the protocol is always &"local-"& followed by
4358 one of those same names. For &%-bS%& (batched SMTP) however, the protocol can
4359 be set by &%-oMr%&. Repeated use of this option is not supported.
4361 .vitem &%-oMs%&&~<&'host&~name'&>
4362 .oindex "&%-oMs%&"
4363 .cindex "sender" "host name, specifying for local message"
4364 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMs%&
4365 option sets the sender host name in &$sender_host_name$&. When this option is
4366 present, Exim does not attempt to look up a host name from an IP address; it
4367 uses the name it is given.
4369 .vitem &%-oMt%&&~<&'ident&~string'&>
4370 .oindex "&%-oMt%&"
4371 .cindex "sender" "ident string, specifying for local message"
4372 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMt%&
4373 option sets the sender ident value in &$sender_ident$&. The default setting for
4374 local callers is the login id of the calling process, except when &%-bh%& is
4375 used, when there is no default.
4377 .vitem &%-om%&
4378 .oindex "&%-om%&"
4379 .cindex "Sendmail compatibility" "&%-om%& option ignored"
4380 In Sendmail, this option means &"me too"&, indicating that the sender of a
4381 message should receive a copy of the message if the sender appears in an alias
4382 expansion. Exim always does this, so the option does nothing.
4384 .vitem &%-oo%&
4385 .oindex "&%-oo%&"
4386 .cindex "Sendmail compatibility" "&%-oo%& option ignored"
4387 This option is ignored. In Sendmail it specifies &"old style headers"&,
4388 whatever that means.
4390 .vitem &%-oP%&&~<&'path'&>
4391 .oindex "&%-oP%&"
4392 .cindex "pid (process id)" "of daemon"
4393 .cindex "daemon" "process id (pid)"
4394 This option is useful only in conjunction with &%-bd%& or &%-q%& with a time
4395 value. The option specifies the file to which the process id of the daemon is
4396 written. When &%-oX%& is used with &%-bd%&, or when &%-q%& with a time is used
4397 without &%-bd%&, this is the only way of causing Exim to write a pid file,
4398 because in those cases, the normal pid file is not used.
4400 .new
4401 .vitem &%-oPX%&
4402 .oindex "&%-oPX%&"
4403 .cindex "pid (process id)" "of daemon"
4404 .cindex "daemon" "process id (pid)"
4405 This option is not intended for general use.
4406 The daemon uses it when terminating due to a SIGTEM, possibly in
4407 combination with &%-oP%&&~<&'path'&>.
4408 It causes the pid file to be removed.
4409 .wen
4411 .vitem &%-or%&&~<&'time'&>
4412 .oindex "&%-or%&"
4413 .cindex "timeout" "for non-SMTP input"
4414 This option sets a timeout value for incoming non-SMTP messages. If it is not
4415 set, Exim will wait forever for the standard input. The value can also be set
4416 by the &%receive_timeout%& option. The format used for specifying times is
4417 described in section &<<SECTtimeformat>>&.
4419 .vitem &%-os%&&~<&'time'&>
4420 .oindex "&%-os%&"
4421 .cindex "timeout" "for SMTP input"
4422 .cindex "SMTP" "input timeout"
4423 This option sets a timeout value for incoming SMTP messages. The timeout
4424 applies to each SMTP command and block of data. The value can also be set by
4425 the &%smtp_receive_timeout%& option; it defaults to 5 minutes. The format used
4426 for specifying times is described in section &<<SECTtimeformat>>&.
4428 .vitem &%-ov%&
4429 .oindex "&%-ov%&"
4430 This option has exactly the same effect as &%-v%&.
4432 .vitem &%-oX%&&~<&'number&~or&~string'&>
4433 .oindex "&%-oX%&"
4434 .cindex "TCP/IP" "setting listening ports"
4435 .cindex "TCP/IP" "setting listening interfaces"
4436 .cindex "port" "receiving TCP/IP"
4437 This option is relevant only when the &%-bd%& (start listening daemon) option
4438 is also given. It controls which ports and interfaces the daemon uses. Details
4439 of the syntax, and how it interacts with configuration file options, are given
4440 in chapter &<<CHAPinterfaces>>&. When &%-oX%& is used to start a daemon, no pid
4441 file is written unless &%-oP%& is also present to specify a pid filename.
4443 .vitem &%-pd%&
4444 .oindex "&%-pd%&"
4445 .cindex "Perl" "starting the interpreter"
4446 This option applies when an embedded Perl interpreter is linked with Exim (see
4447 chapter &<<CHAPperl>>&). It overrides the setting of the &%perl_at_start%&
4448 option, forcing the starting of the interpreter to be delayed until it is
4449 needed.
4451 .vitem &%-ps%&
4452 .oindex "&%-ps%&"
4453 .cindex "Perl" "starting the interpreter"
4454 This option applies when an embedded Perl interpreter is linked with Exim (see
4455 chapter &<<CHAPperl>>&). It overrides the setting of the &%perl_at_start%&
4456 option, forcing the starting of the interpreter to occur as soon as Exim is
4457 started.
4459 .vitem &%-p%&<&'rval'&>:<&'sval'&>
4460 .oindex "&%-p%&"
4461 For compatibility with Sendmail, this option is equivalent to
4462 .display
4463 &`-oMr`& <&'rval'&> &`-oMs`& <&'sval'&>
4464 .endd
4465 It sets the incoming protocol and host name (for trusted callers). The
4466 host name and its colon can be omitted when only the protocol is to be set.
4467 Note the Exim already has two private options, &%-pd%& and &%-ps%&, that refer
4468 to embedded Perl. It is therefore impossible to set a protocol value of &`d`&
4469 or &`s`& using this option (but that does not seem a real limitation).
4470 Repeated use of this option is not supported.
4472 .vitem &%-q%&
4473 .oindex "&%-q%&"
4474 .cindex "queue runner" "starting manually"
4475 This option is normally restricted to admin users. However, there is a
4476 configuration option called &%prod_requires_admin%& which can be set false to
4477 relax this restriction (and also the same requirement for the &%-M%&, &%-R%&,
4478 and &%-S%& options).
4480 .cindex "queue runner" "description of operation"
4481 If other commandline options do not specify an action,
4482 the &%-q%& option starts one queue runner process. This scans the queue of
4483 waiting messages, and runs a delivery process for each one in turn. It waits
4484 for each delivery process to finish before starting the next one. A delivery
4485 process may not actually do any deliveries if the retry times for the addresses
4486 have not been reached. Use &%-qf%& (see below) if you want to override this.
4488 If
4489 .cindex "SMTP" "passed connection"
4490 .cindex "SMTP" "multiple deliveries"
4491 .cindex "multiple SMTP deliveries"
4492 the delivery process spawns other processes to deliver other messages down
4493 passed SMTP connections, the queue runner waits for these to finish before
4494 proceeding.
4496 When all the queued messages have been considered, the original queue runner
4497 process terminates. In other words, a single pass is made over the waiting
4498 mail, one message at a time. Use &%-q%& with a time (see below) if you want
4499 this to be repeated periodically.
4501 Exim processes the waiting messages in an unpredictable order. It isn't very
4502 random, but it is likely to be different each time, which is all that matters.
4503 If one particular message screws up a remote MTA, other messages to the same
4504 MTA have a chance of getting through if they get tried first.
4506 It is possible to cause the messages to be processed in lexical message id
4507 order, which is essentially the order in which they arrived, by setting the
4508 &%queue_run_in_order%& option, but this is not recommended for normal use.
4510 .vitem &%-q%&<&'qflags'&>
4511 The &%-q%& option may be followed by one or more flag letters that change its
4512 behaviour. They are all optional, but if more than one is present, they must
4513 appear in the correct order. Each flag is described in a separate item below.
4515 .vitem &%-qq...%&
4516 .oindex "&%-qq%&"
4517 .cindex "queue" "double scanning"
4518 .cindex "queue" "routing"
4519 .cindex "routing" "whole queue before delivery"
4520 .cindex "first pass routing"
4521 An option starting with &%-qq%& requests a two-stage queue run. In the first
4522 stage, the queue is scanned as if the &%queue_smtp_domains%& option matched
4523 every domain. Addresses are routed, local deliveries happen, but no remote
4524 transports are run.
4526 .new
4527 Performance will be best if the &%queue_run_in_order%& option is false.
4528 .wen
4530 .cindex "hints database" "remembering routing"
4531 The hints database that remembers which messages are waiting for specific hosts
4532 is updated, as if delivery to those hosts had been deferred. After this is
4533 complete, a second, normal queue scan happens, with routing and delivery taking
4534 place as normal. Messages that are routed to the same host should mostly be
4535 delivered down a single SMTP
4536 .cindex "SMTP" "passed connection"
4537 .cindex "SMTP" "multiple deliveries"
4538 .cindex "multiple SMTP deliveries"
4539 connection because of the hints that were set up during the first queue scan.
4540 This option may be useful for hosts that are connected to the Internet
4541 intermittently.
4543 .vitem &%-q[q]i...%&
4544 .oindex "&%-qi%&"
4545 .cindex "queue" "initial delivery"
4546 If the &'i'& flag is present, the queue runner runs delivery processes only for
4547 those messages that haven't previously been tried. (&'i'& stands for &"initial
4548 delivery"&.) This can be helpful if you are putting messages in the queue using
4549 &%-odq%& and want a queue runner just to process the new messages.
4551 .vitem &%-q[q][i]f...%&
4552 .oindex "&%-qf%&"
4553 .cindex "queue" "forcing delivery"
4554 .cindex "delivery" "forcing in queue run"
4555 If one &'f'& flag is present, a delivery attempt is forced for each non-frozen
4556 message, whereas without &'f'& only those non-frozen addresses that have passed
4557 their retry times are tried.
4559 .vitem &%-q[q][i]ff...%&
4560 .oindex "&%-qff%&"
4561 .cindex "frozen messages" "forcing delivery"
4562 If &'ff'& is present, a delivery attempt is forced for every message, whether
4563 frozen or not.
4565 .vitem &%-q[q][i][f[f]]l%&
4566 .oindex "&%-ql%&"
4567 .cindex "queue" "local deliveries only"
4568 The &'l'& (the letter &"ell"&) flag specifies that only local deliveries are to
4569 be done. If a message requires any remote deliveries, it remains in the queue
4570 for later delivery.
4572 .vitem &%-q[q][i][f[f]][l][G<name>[/<time>]]]%&
4573 .oindex "&%-qG%&"
4574 .cindex queue named
4575 .cindex "named queues" "deliver from"
4576 .cindex "queue" "delivering specific messages"
4577 If the &'G'& flag and a name is present, the queue runner operates on the
4578 queue with the given name rather than the default queue.
4579 The name should not contain a &'/'& character.
4580 For a periodic queue run (see below)
4581 append to the name a slash and a time value.
4583 If other commandline options specify an action, a &'-qG<name>'& option
4584 will specify a queue to operate on.
4585 For example:
4586 .code
4587 exim -bp -qGquarantine
4588 mailq -qGquarantine
4589 exim -qGoffpeak -Rf @special.domain.example
4590 .endd
4592 .vitem &%-q%&<&'qflags'&>&~<&'start&~id'&>&~<&'end&~id'&>
4593 When scanning the queue, Exim can be made to skip over messages whose ids are
4594 lexically less than a given value by following the &%-q%& option with a
4595 starting message id. For example:
4596 .code
4597 exim -q 0t5C6f-0000c8-00
4598 .endd
4599 Messages that arrived earlier than &`0t5C6f-0000c8-00`& are not inspected. If a
4600 second message id is given, messages whose ids are lexically greater than it
4601 are also skipped. If the same id is given twice, for example,
4602 .code
4603 exim -q 0t5C6f-0000c8-00 0t5C6f-0000c8-00
4604 .endd
4605 just one delivery process is started, for that message. This differs from
4606 &%-M%& in that retry data is respected, and it also differs from &%-Mc%& in
4607 that it counts as a delivery from a queue run. Note that the selection
4608 mechanism does not affect the order in which the messages are scanned. There
4609 are also other ways of selecting specific sets of messages for delivery in a
4610 queue run &-- see &%-R%& and &%-S%&.
4612 .vitem &%-q%&<&'qflags'&><&'time'&>
4613 .cindex "queue runner" "starting periodically"
4614 .cindex "periodic queue running"
4615 When a time value is present, the &%-q%& option causes Exim to run as a daemon,
4616 starting a queue runner process at intervals specified by the given time value
4617 (whose format is described in section &<<SECTtimeformat>>&). This form of the
4618 &%-q%& option is commonly combined with the &%-bd%& option, in which case a
4619 single daemon process handles both functions. A common way of starting up a
4620 combined daemon at system boot time is to use a command such as
4621 .code
4622 /usr/exim/bin/exim -bd -q30m
4623 .endd
4624 Such a daemon listens for incoming SMTP calls, and also starts a queue runner
4625 process every 30 minutes.
4627 When a daemon is started by &%-q%& with a time value, but without &%-bd%&, no
4628 pid file is written unless one is explicitly requested by the &%-oP%& option.
4630 .vitem &%-qR%&<&'rsflags'&>&~<&'string'&>
4631 .oindex "&%-qR%&"
4632 This option is synonymous with &%-R%&. It is provided for Sendmail
4633 compatibility.
4635 .vitem &%-qS%&<&'rsflags'&>&~<&'string'&>
4636 .oindex "&%-qS%&"
4637 This option is synonymous with &%-S%&.
4639 .vitem &%-R%&<&'rsflags'&>&~<&'string'&>
4640 .oindex "&%-R%&"
4641 .cindex "queue runner" "for specific recipients"
4642 .cindex "delivery" "to given domain"
4643 .cindex "domain" "delivery to"
4644 The <&'rsflags'&> may be empty, in which case the white space before the string
4645 is optional, unless the string is &'f'&, &'ff'&, &'r'&, &'rf'&, or &'rff'&,
4646 which are the possible values for <&'rsflags'&>. White space is required if
4647 <&'rsflags'&> is not empty.
4649 This option is similar to &%-q%& with no time value, that is, it causes Exim to
4650 perform a single queue run, except that, when scanning the messages on the
4651 queue, Exim processes only those that have at least one undelivered recipient
4652 address containing the given string, which is checked in a case-independent
4653 way. If the <&'rsflags'&> start with &'r'&, <&'string'&> is interpreted as a
4654 regular expression; otherwise it is a literal string.
4656 If you want to do periodic queue runs for messages with specific recipients,
4657 you can combine &%-R%& with &%-q%& and a time value. For example:
4658 .code
4659 exim -q25m -R @special.domain.example
4660 .endd
4661 This example does a queue run for messages with recipients in the given domain
4662 every 25 minutes. Any additional flags that are specified with &%-q%& are
4663 applied to each queue run.
4665 Once a message is selected for delivery by this mechanism, all its addresses
4666 are processed. For the first selected message, Exim overrides any retry
4667 information and forces a delivery attempt for each undelivered address. This
4668 means that if delivery of any address in the first message is successful, any
4669 existing retry information is deleted, and so delivery attempts for that
4670 address in subsequently selected messages (which are processed without forcing)
4671 will run. However, if delivery of any address does not succeed, the retry
4672 information is updated, and in subsequently selected messages, the failing
4673 address will be skipped.
4675 .cindex "frozen messages" "forcing delivery"
4676 If the <&'rsflags'&> contain &'f'& or &'ff'&, the delivery forcing applies to
4677 all selected messages, not just the first; frozen messages are included when
4678 &'ff'& is present.
4680 The &%-R%& option makes it straightforward to initiate delivery of all messages
4681 to a given domain after a host has been down for some time. When the SMTP
4682 command ETRN is accepted by its ACL (see chapter &<<CHAPACL>>&), its default
4683 effect is to run Exim with the &%-R%& option, but it can be configured to run
4684 an arbitrary command instead.
4686 .vitem &%-r%&
4687 .oindex "&%-r%&"
4688 This is a documented (for Sendmail) obsolete alternative name for &%-f%&.
4690 .vitem &%-S%&<&'rsflags'&>&~<&'string'&>
4691 .oindex "&%-S%&"
4692 .cindex "delivery" "from given sender"
4693 .cindex "queue runner" "for specific senders"
4694 This option acts like &%-R%& except that it checks the string against each
4695 message's sender instead of against the recipients. If &%-R%& is also set, both
4696 conditions must be met for a message to be selected. If either of the options
4697 has &'f'& or &'ff'& in its flags, the associated action is taken.
4699 .vitem &%-Tqt%&&~<&'times'&>
4700 .oindex "&%-Tqt%&"
4701 This is an option that is exclusively for use by the Exim testing suite. It is not
4702 recognized when Exim is run normally. It allows for the setting up of explicit
4703 &"queue times"& so that various warning/retry features can be tested.
4705 .vitem &%-t%&
4706 .oindex "&%-t%&"
4707 .cindex "recipient" "extracting from header lines"
4708 .cindex "&'Bcc:'& header line"
4709 .cindex "&'Cc:'& header line"
4710 .cindex "&'To:'& header line"
4711 When Exim is receiving a locally-generated, non-SMTP message on its standard
4712 input, the &%-t%& option causes the recipients of the message to be obtained
4713 from the &'To:'&, &'Cc:'&, and &'Bcc:'& header lines in the message instead of
4714 from the command arguments. The addresses are extracted before any rewriting
4715 takes place and the &'Bcc:'& header line, if present, is then removed.
4717 .cindex "Sendmail compatibility" "&%-t%& option"
4718 If the command has any arguments, they specify addresses to which the message
4719 is &'not'& to be delivered. That is, the argument addresses are removed from
4720 the recipients list obtained from the headers. This is compatible with Smail 3
4721 and in accordance with the documented behaviour of several versions of
4722 Sendmail, as described in man pages on a number of operating systems (e.g.
4723 Solaris 8, IRIX 6.5, HP-UX 11). However, some versions of Sendmail &'add'&
4724 argument addresses to those obtained from the headers, and the O'Reilly
4725 Sendmail book documents it that way. Exim can be made to add argument addresses
4726 instead of subtracting them by setting the option
4727 &%extract_addresses_remove_arguments%& false.
4729 .cindex "&%Resent-%& header lines" "with &%-t%&"
4730 If there are any &%Resent-%& header lines in the message, Exim extracts
4731 recipients from all &'Resent-To:'&, &'Resent-Cc:'&, and &'Resent-Bcc:'& header
4732 lines instead of from &'To:'&, &'Cc:'&, and &'Bcc:'&. This is for compatibility
4733 with Sendmail and other MTAs. (Prior to release 4.20, Exim gave an error if
4734 &%-t%& was used in conjunction with &%Resent-%& header lines.)
4736 RFC 2822 talks about different sets of &%Resent-%& header lines (for when a
4737 message is resent several times). The RFC also specifies that they should be
4738 added at the front of the message, and separated by &'Received:'& lines. It is
4739 not at all clear how &%-t%& should operate in the present of multiple sets,
4740 nor indeed exactly what constitutes a &"set"&.
4741 In practice, it seems that MUAs do not follow the RFC. The &%Resent-%& lines
4742 are often added at the end of the header, and if a message is resent more than
4743 once, it is common for the original set of &%Resent-%& headers to be renamed as
4744 &%X-Resent-%& when a new set is added. This removes any possible ambiguity.
4746 .vitem &%-ti%&
4747 .oindex "&%-ti%&"
4748 This option is exactly equivalent to &%-t%& &%-i%&. It is provided for
4749 compatibility with Sendmail.
4751 .vitem &%-tls-on-connect%&
4752 .oindex "&%-tls-on-connect%&"
4753 .cindex "TLS" "use without STARTTLS"
4754 .cindex "TLS" "automatic start"
4755 This option is available when Exim is compiled with TLS support. It forces all
4756 incoming SMTP connections to behave as if the incoming port is listed in the
4757 &%tls_on_connect_ports%& option. See section &<<SECTsupobssmt>>& and chapter
4758 &<<CHAPTLS>>& for further details.
4761 .vitem &%-U%&
4762 .oindex "&%-U%&"
4763 .cindex "Sendmail compatibility" "&%-U%& option ignored"
4764 Sendmail uses this option for &"initial message submission"&, and its
4765 documentation states that in future releases, it may complain about
4766 syntactically invalid messages rather than fixing them when this flag is not
4767 set. Exim ignores this option.
4769 .vitem &%-v%&
4770 .oindex "&%-v%&"
4771 This option causes Exim to write information to the standard error stream,
4772 describing what it is doing. In particular, it shows the log lines for
4773 receiving and delivering a message, and if an SMTP connection is made, the SMTP
4774 dialogue is shown. Some of the log lines shown may not actually be written to
4775 the log if the setting of &%log_selector%& discards them. Any relevant
4776 selectors are shown with each log line. If none are shown, the logging is
4777 unconditional.
4779 .vitem &%-x%&
4780 .oindex "&%-x%&"
4781 AIX uses &%-x%& for a private purpose (&"mail from a local mail program has
4782 National Language Support extended characters in the body of the mail item"&).
4783 It sets &%-x%& when calling the MTA from its &%mail%& command. Exim ignores
4784 this option.
4786 .vitem &%-X%&&~<&'logfile'&>
4787 .oindex "&%-X%&"
4788 This option is interpreted by Sendmail to cause debug information to be sent
4789 to the named file. It is ignored by Exim.
4791 .vitem &%-z%&&~<&'log-line'&>
4792 .oindex "&%-z%&"
4793 This option writes its argument to Exim's logfile.
4794 Use is restricted to administrators; the intent is for operational notes.
4795 Quotes should be used to maintain a multi-word item as a single argument,
4796 under most shells.
4797 .endlist
4799 .ecindex IIDclo1
4800 .ecindex IIDclo2
4803 . ////////////////////////////////////////////////////////////////////////////
4804 . Insert a stylized DocBook comment here, to identify the end of the command
4805 . line options. This is for the benefit of the Perl script that automatically
4806 . creates a man page for the options.
4807 . ////////////////////////////////////////////////////////////////////////////
4809 .literal xml
4810 <!-- === End of command line options === -->
4811 .literal off