[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 "4.92"
49 .include ./local_params
51 .set ACL "access control lists (ACLs)"
52 .set I "&nbsp;&nbsp;&nbsp;&nbsp;"
54 .macro copyyear
55 2018
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 .cindex "documentation"
375 This edition of the Exim specification applies to version &version() of Exim.
376 Substantive changes from the &previousversion; edition are marked in some
377 renditions of this document; this paragraph is so marked if the rendition is
378 capable of showing a change indicator.
380 This document is very much a reference manual; it is not a tutorial. The reader
381 is expected to have some familiarity with the SMTP mail transfer protocol and
382 with general Unix system administration. Although there are some discussions
383 and examples in places, the information is mostly organized in a way that makes
384 it easy to look up, rather than in a natural order for sequential reading.
385 Furthermore, this manual aims to cover every aspect of Exim in detail, including
386 a number of rarely-used, special-purpose features that are unlikely to be of
387 very wide interest.
389 .cindex "books about Exim"
390 An &"easier"& discussion of Exim which provides more in-depth explanatory,
391 introductory, and tutorial material can be found in a book entitled &'The Exim
392 SMTP Mail Server'& (second edition, 2007), published by UIT Cambridge
393 (&url(https://www.uit.co.uk/exim-book/)).
395 The book also contains a chapter that gives a general introduction to SMTP and
396 Internet mail. Inevitably, however, the book is unlikely to be fully up-to-date
397 with the latest release of Exim. (Note that the earlier book about Exim,
398 published by O'Reilly, covers Exim 3, and many things have changed in Exim 4.)
400 .cindex "Debian" "information sources"
401 If you are using a Debian distribution of Exim, you will find information about
402 Debian-specific features in the file
403 &_/usr/share/doc/exim4-base/README.Debian_&.
404 The command &(man update-exim.conf)& is another source of Debian-specific
405 information.
407 .cindex "&_doc/NewStuff_&"
408 .cindex "&_doc/ChangeLog_&"
409 .cindex "change log"
410 As Exim develops, there may be features in newer versions that have not
411 yet made it into this document, which is updated only when the most significant
412 digit of the fractional part of the version number changes. Specifications of
413 new features that are not yet in this manual are placed in the file
414 &_doc/NewStuff_& in the Exim distribution.
416 Some features may be classified as &"experimental"&. These may change
417 incompatibly while they are developing, or even be withdrawn. For this reason,
418 they are not documented in this manual. Information about experimental features
419 can be found in the file &_doc/experimental.txt_&.
421 All changes to Exim (whether new features, bug fixes, or other kinds of
422 change) are noted briefly in the file called &_doc/ChangeLog_&.
424 .cindex "&_doc/spec.txt_&"
425 This specification itself is available as an ASCII file in &_doc/spec.txt_& so
426 that it can easily be searched with a text editor. Other files in the &_doc_&
427 directory are:
429 .table2 100pt
430 .row &_OptionLists.txt_& "list of all options in alphabetical order"
431 .row &_dbm.discuss.txt_& "discussion about DBM libraries"
432 .row &_exim.8_& "a man page of Exim's command line options"
433 .row &_experimental.txt_& "documentation of experimental features"
434 .row &_filter.txt_& "specification of the filter language"
435 .row &_Exim3.upgrade_& "upgrade notes from release 2 to release 3"
436 .row &_Exim4.upgrade_& "upgrade notes from release 3 to release 4"
437 .row &_openssl.txt_& "installing a current OpenSSL release"
438 .endtable
440 The main specification and the specification of the filtering language are also
441 available in other formats (HTML, PostScript, PDF, and Texinfo). Section
442 &<<SECTavail>>& below tells you how to get hold of these.
446 .section "FTP site and websites" "SECID2"
447 .cindex "website"
448 .cindex "FTP site"
449 The primary site for Exim source distributions is the &%exim.org%& FTP site,
450 available over HTTPS, HTTP and FTP. These services, and the &%exim.org%&
451 website, are hosted at the University of Cambridge.
453 .cindex "wiki"
454 .cindex "FAQ"
455 As well as Exim distribution tar files, the Exim website contains a number of
456 differently formatted versions of the documentation. A recent addition to the
457 online information is the Exim wiki (&url(https://wiki.exim.org)),
458 which contains what used to be a separate FAQ, as well as various other
459 examples, tips, and know-how that have been contributed by Exim users.
460 The wiki site should always redirect to the correct place, which is currently
461 provided by GitHub, and is open to editing by anyone with a GitHub account.
463 .cindex Bugzilla
464 An Exim Bugzilla exists at &url(https://bugs.exim.org). You can use
465 this to report bugs, and also to add items to the wish list. Please search
466 first to check that you are not duplicating a previous entry.
467 Please do not ask for configuration help in the bug-tracker.
470 .section "Mailing lists" "SECID3"
471 .cindex "mailing lists" "for Exim users"
472 The following Exim mailing lists exist:
474 .table2 140pt
475 .row &'exim-announce@exim.org'& "Moderated, low volume announcements list"
476 .row &'exim-users@exim.org'& "General discussion list"
477 .row &'exim-dev@exim.org'& "Discussion of bugs, enhancements, etc."
478 .row &'exim-cvs@exim.org'& "Automated commit messages from the VCS"
479 .endtable
481 You can subscribe to these lists, change your existing subscriptions, and view
482 or search the archives via the mailing lists link on the Exim home page.
483 .cindex "Debian" "mailing list for"
484 If you are using a Debian distribution of Exim, you may wish to subscribe to
485 the Debian-specific mailing list &'pkg-exim4-users@lists.alioth.debian.org'&
486 via this web page:
487 .display
488 &url(https://alioth-lists.debian.net/cgi-bin/mailman/listinfo/pkg-exim4-users)
489 .endd
490 Please ask Debian-specific questions on that list and not on the general Exim
491 lists.
493 .section "Bug reports" "SECID5"
494 .cindex "bug reports"
495 .cindex "reporting bugs"
496 Reports of obvious bugs can be emailed to &'bugs@exim.org'& or reported
497 via the Bugzilla (&url(https://bugs.exim.org)). However, if you are unsure
498 whether some behaviour is a bug or not, the best thing to do is to post a
499 message to the &'exim-dev'& mailing list and have it discussed.
503 .section "Where to find the Exim distribution" "SECTavail"
504 .cindex "FTP site"
505 .cindex "HTTPS download site"
506 .cindex "distribution" "FTP site"
507 .cindex "distribution" "https site"
508 The master distribution site for the Exim distribution is
509 .display
510 &url(https://downloads.exim.org/)
511 .endd
512 The service is available over HTTPS, HTTP and FTP.
513 We encourage people to migrate to HTTPS.
515 The content served at &url(https://downloads.exim.org/) is identical to the
516 content served at &url(https://ftp.exim.org/pub/exim) and
517 &url(ftp://ftp.exim.org/pub/exim).
519 If accessing via a hostname containing &'ftp'&, then the file references that
520 follow are relative to the &_exim_& directories at these sites.
521 If accessing via the hostname &'downloads'& then the subdirectories described
522 here are top-level directories.
524 There are now quite a number of independent mirror sites around
525 the world. Those that I know about are listed in the file called &_Mirrors_&.
527 Within the top exim directory there are subdirectories called &_exim3_& (for
528 previous Exim 3 distributions), &_exim4_& (for the latest Exim 4
529 distributions), and &_Testing_& for testing versions. In the &_exim4_&
530 subdirectory, the current release can always be found in files called
531 .display
532 &_exim-n.nn.tar.xz_&
533 &_exim-n.nn.tar.gz_&
534 &_exim-n.nn.tar.bz2_&
535 .endd
536 where &'n.nn'& is the highest such version number in the directory. The three
537 files contain identical data; the only difference is the type of compression.
538 The &_.xz_& file is usually the smallest, while the &_.gz_& file is the
539 most portable to old systems.
541 .cindex "distribution" "signing details"
542 .cindex "distribution" "public key"
543 .cindex "public key for signed distribution"
544 The distributions will be PGP signed by an individual key of the Release
545 Coordinator. This key will have a uid containing an email address in the
546 &'exim.org'& domain and will have signatures from other people, including
547 other Exim maintainers. We expect that the key will be in the "strong set" of
548 PGP keys. There should be a trust path to that key from the Exim Maintainer's
549 PGP keys, a version of which can be found in the release directory in the file
550 &_Exim-Maintainers-Keyring.asc_&. All keys used will be available in public keyserver pools,
551 such as &'pool.sks-keyservers.net'&.
553 At the time of the last update, releases were being made by Jeremy Harris and signed
554 with key &'0xBCE58C8CE41F32DF'&. Other recent keys used for signing are those
555 of Heiko Schlittermann, &'0x26101B62F69376CE'&,
556 and of Phil Pennock, &'0x4D1E900E14C1CC04'&.
558 The signatures for the tar bundles are in:
559 .display
560 &_exim-n.nn.tar.xz.asc_&
561 &_exim-n.nn.tar.gz.asc_&
562 &_exim-n.nn.tar.bz2.asc_&
563 .endd
564 For each released version, the log of changes is made available in a
565 separate file in the directory &_ChangeLogs_& so that it is possible to
566 find out what has changed without having to download the entire distribution.
568 .cindex "documentation" "available formats"
569 The main distribution contains ASCII versions of this specification and other
570 documentation; other formats of the documents are available in separate files
571 inside the &_exim4_& directory of the FTP site:
572 .display
573 &_exim-html-n.nn.tar.gz_&
574 &_exim-pdf-n.nn.tar.gz_&
575 &_exim-postscript-n.nn.tar.gz_&
576 &_exim-texinfo-n.nn.tar.gz_&
577 .endd
578 These tar files contain only the &_doc_& directory, not the complete
579 distribution, and are also available in &_.bz2_& and &_.xz_& forms.
582 .section "Limitations" "SECID6"
583 .ilist
584 .cindex "limitations of Exim"
585 .cindex "bang paths" "not handled by Exim"
586 Exim is designed for use as an Internet MTA, and therefore handles addresses in
587 RFC 2822 domain format only. It cannot handle UUCP &"bang paths"&, though
588 simple two-component bang paths can be converted by a straightforward rewriting
589 configuration. This restriction does not prevent Exim from being interfaced to
590 UUCP as a transport mechanism, provided that domain addresses are used.
591 .next
592 .cindex "domainless addresses"
593 .cindex "address" "without domain"
594 Exim insists that every address it handles has a domain attached. For incoming
595 local messages, domainless addresses are automatically qualified with a
596 configured domain value. Configuration options specify from which remote
597 systems unqualified addresses are acceptable. These are then qualified on
598 arrival.
599 .next
600 .cindex "transport" "external"
601 .cindex "external transports"
602 The only external transport mechanisms that are currently implemented are SMTP
603 and LMTP over a TCP/IP network (including support for IPv6). However, a pipe
604 transport is available, and there are facilities for writing messages to files
605 and pipes, optionally in &'batched SMTP'& format; these facilities can be used
606 to send messages to other transport mechanisms such as UUCP, provided they can
607 handle domain-style addresses. Batched SMTP input is also catered for.
608 .next
609 Exim is not designed for storing mail for dial-in hosts. When the volumes of
610 such mail are large, it is better to get the messages &"delivered"& into files
611 (that is, off Exim's queue) and subsequently passed on to the dial-in hosts by
612 other means.
613 .next
614 Although Exim does have basic facilities for scanning incoming messages, these
615 are not comprehensive enough to do full virus or spam scanning. Such operations
616 are best carried out using additional specialized software packages. If you
617 compile Exim with the content-scanning extension, straightforward interfaces to
618 a number of common scanners are provided.
619 .endlist
622 .section "Runtime configuration" "SECID7"
623 Exim's runtime configuration is held in a single text file that is divided
624 into a number of sections. The entries in this file consist of keywords and
625 values, in the style of Smail 3 configuration files. A default configuration
626 file which is suitable for simple online installations is provided in the
627 distribution, and is described in chapter &<<CHAPdefconfil>>& below.
630 .section "Calling interface" "SECID8"
631 .cindex "Sendmail compatibility" "command line interface"
632 Like many MTAs, Exim has adopted the Sendmail command line interface so that it
633 can be a straight replacement for &_/usr/lib/sendmail_& or
634 &_/usr/sbin/sendmail_& when sending mail, but you do not need to know anything
635 about Sendmail in order to run Exim. For actions other than sending messages,
636 Sendmail-compatible options also exist, but those that produce output (for
637 example, &%-bp%&, which lists the messages in the queue) do so in Exim's own
638 format. There are also some additional options that are compatible with Smail
639 3, and some further options that are new to Exim. Chapter &<<CHAPcommandline>>&
640 documents all Exim's command line options. This information is automatically
641 made into the man page that forms part of the Exim distribution.
643 Control of messages in the queue can be done via certain privileged command
644 line options. There is also an optional monitor program called &'eximon'&,
645 which displays current information in an X window, and which contains a menu
646 interface to Exim's command line administration options.
650 .section "Terminology" "SECID9"
651 .cindex "terminology definitions"
652 .cindex "body of message" "definition of"
653 The &'body'& of a message is the actual data that the sender wants to transmit.
654 It is the last part of a message and is separated from the &'header'& (see
655 below) by a blank line.
657 .cindex "bounce message" "definition of"
658 When a message cannot be delivered, it is normally returned to the sender in a
659 delivery failure message or a &"non-delivery report"& (NDR). The term
660 &'bounce'& is commonly used for this action, and the error reports are often
661 called &'bounce messages'&. This is a convenient shorthand for &"delivery
662 failure error report"&. Such messages have an empty sender address in the
663 message's &'envelope'& (see below) to ensure that they cannot themselves give
664 rise to further bounce messages.
666 The term &'default'& appears frequently in this manual. It is used to qualify a
667 value which is used in the absence of any setting in the configuration. It may
668 also qualify an action which is taken unless a configuration setting specifies
669 otherwise.
671 The term &'defer'& is used when the delivery of a message to a specific
672 destination cannot immediately take place for some reason (a remote host may be
673 down, or a user's local mailbox may be full). Such deliveries are &'deferred'&
674 until a later time.
676 The word &'domain'& is sometimes used to mean all but the first component of a
677 host's name. It is &'not'& used in that sense here, where it normally refers to
678 the part of an email address following the @ sign.
680 .cindex "envelope, definition of"
681 .cindex "sender" "definition of"
682 A message in transit has an associated &'envelope'&, as well as a header and a
683 body. The envelope contains a sender address (to which bounce messages should
684 be delivered), and any number of recipient addresses. References to the
685 sender or the recipients of a message usually mean the addresses in the
686 envelope. An MTA uses these addresses for delivery, and for returning bounce
687 messages, not the addresses that appear in the header lines.
689 .cindex "message" "header, definition of"
690 .cindex "header section" "definition of"
691 The &'header'& of a message is the first part of a message's text, consisting
692 of a number of lines, each of which has a name such as &'From:'&, &'To:'&,
693 &'Subject:'&, etc. Long header lines can be split over several text lines by
694 indenting the continuations. The header is separated from the body by a blank
695 line.
697 .cindex "local part" "definition of"
698 .cindex "domain" "definition of"
699 The term &'local part'&, which is taken from RFC 2822, is used to refer to the
700 part of an email address that precedes the @ sign. The part that follows the
701 @ sign is called the &'domain'& or &'mail domain'&.
703 .cindex "local delivery" "definition of"
704 .cindex "remote delivery, definition of"
705 The terms &'local delivery'& and &'remote delivery'& are used to distinguish
706 delivery to a file or a pipe on the local host from delivery by SMTP over
707 TCP/IP to another host. As far as Exim is concerned, all hosts other than the
708 host it is running on are &'remote'&.
710 .cindex "return path" "definition of"
711 &'Return path'& is another name that is used for the sender address in a
712 message's envelope.
714 .cindex "queue" "definition of"
715 The term &'queue'& is used to refer to the set of messages awaiting delivery
716 because this term is in widespread use in the context of MTAs. However, in
717 Exim's case, the reality is more like a pool than a queue, because there is
718 normally no ordering of waiting messages.
720 .cindex "queue runner" "definition of"
721 The term &'queue runner'& is used to describe a process that scans the queue
722 and attempts to deliver those messages whose retry times have come. This term
723 is used by other MTAs and also relates to the command &%runq%&, but in Exim
724 the waiting messages are normally processed in an unpredictable order.
726 .cindex "spool directory" "definition of"
727 The term &'spool directory'& is used for a directory in which Exim keeps the
728 messages in its queue &-- that is, those that it is in the process of
729 delivering. This should not be confused with the directory in which local
730 mailboxes are stored, which is called a &"spool directory"& by some people. In
731 the Exim documentation, &"spool"& is always used in the first sense.
738 . ////////////////////////////////////////////////////////////////////////////
739 . ////////////////////////////////////////////////////////////////////////////
741 .chapter "Incorporated code" "CHID2"
742 .cindex "incorporated code"
743 .cindex "regular expressions" "library"
744 .cindex "PCRE"
745 .cindex "OpenDMARC"
746 A number of pieces of external code are included in the Exim distribution.
748 .ilist
749 Regular expressions are supported in the main Exim program and in the
750 Exim monitor using the freely-distributable PCRE library, copyright
751 &copy; University of Cambridge. The source to PCRE is no longer shipped with
752 Exim, so you will need to use the version of PCRE shipped with your system,
753 or obtain and install the full version of the library from
754 &url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre).
755 .next
756 .cindex "cdb" "acknowledgment"
757 Support for the cdb (Constant DataBase) lookup method is provided by code
758 contributed by Nigel Metheringham of (at the time he contributed it) Planet
759 Online Ltd. The implementation is completely contained within the code of Exim.
760 It does not link against an external cdb library. The code contains the
761 following statements:
763 .blockquote
764 Copyright &copy; 1998 Nigel Metheringham, Planet Online Ltd
766 This program is free software; you can redistribute it and/or modify it under
767 the terms of the GNU General Public License as published by the Free Software
768 Foundation; either version 2 of the License, or (at your option) any later
769 version.
770 This code implements Dan Bernstein's Constant DataBase (cdb) spec. Information,
771 the spec and sample code for cdb can be obtained from
772 &url(https://cr.yp.to/cdb.html). This implementation borrows
773 some code from Dan Bernstein's implementation (which has no license
774 restrictions applied to it).
775 .endblockquote
776 .next
777 .cindex "SPA authentication"
778 .cindex "Samba project"
779 .cindex "Microsoft Secure Password Authentication"
780 Client support for Microsoft's &'Secure Password Authentication'& is provided
781 by code contributed by Marc Prud'hommeaux. Server support was contributed by
782 Tom Kistner. This includes code taken from the Samba project, which is released
783 under the Gnu GPL.
784 .next
785 .cindex "Cyrus"
786 .cindex "&'pwcheck'& daemon"
787 .cindex "&'pwauthd'& daemon"
788 Support for calling the Cyrus &'pwcheck'& and &'saslauthd'& daemons is provided
789 by code taken from the Cyrus-SASL library and adapted by Alexander S.
790 Sabourenkov. The permission notice appears below, in accordance with the
791 conditions expressed therein.
793 .blockquote
794 Copyright &copy; 2001 Carnegie Mellon University. All rights reserved.
796 Redistribution and use in source and binary forms, with or without
797 modification, are permitted provided that the following conditions
798 are met:
800 .olist
801 Redistributions of source code must retain the above copyright
802 notice, this list of conditions and the following disclaimer.
803 .next
804 Redistributions in binary form must reproduce the above copyright
805 notice, this list of conditions and the following disclaimer in
806 the documentation and/or other materials provided with the
807 distribution.
808 .next
809 The name &"Carnegie Mellon University"& must not be used to
810 endorse or promote products derived from this software without
811 prior written permission. For permission or any other legal
812 details, please contact
813 .display
814 Office of Technology Transfer
815 Carnegie Mellon University
816 5000 Forbes Avenue
817 Pittsburgh, PA 15213-3890
818 (412) 268-4387, fax: (412) 268-7395
819 tech-transfer@andrew.cmu.edu
820 .endd
821 .next
822 Redistributions of any form whatsoever must retain the following
823 acknowledgment:
825 &"This product includes software developed by Computing Services
826 at Carnegie Mellon University (&url(https://www.cmu.edu/computing/)."&
835 .endlist
836 .endblockquote
838 .next
839 .cindex "Exim monitor" "acknowledgment"
840 .cindex "X-windows"
841 .cindex "Athena"
842 The Exim Monitor program, which is an X-Window application, includes
843 modified versions of the Athena StripChart and TextPop widgets.
844 This code is copyright by DEC and MIT, and their permission notice appears
845 below, in accordance with the conditions expressed therein.
847 .blockquote
848 Copyright 1987, 1988 by Digital Equipment Corporation, Maynard, Massachusetts,
849 and the Massachusetts Institute of Technology, Cambridge, Massachusetts.
851 All Rights Reserved
853 Permission to use, copy, modify, and distribute this software and its
854 documentation for any purpose and without fee is hereby granted,
855 provided that the above copyright notice appear in all copies and that
856 both that copyright notice and this permission notice appear in
857 supporting documentation, and that the names of Digital or MIT not be
858 used in advertising or publicity pertaining to distribution of the
859 software without specific, written prior permission.
868 .endblockquote
870 .next
871 .cindex "opendmarc" "acknowledgment"
872 The DMARC implementation uses the OpenDMARC library which is Copyrighted by
873 The Trusted Domain Project. Portions of Exim source which use OpenDMARC
874 derived code are indicated in the respective source files. The full OpenDMARC
875 license is provided in the LICENSE.opendmarc file contained in the distributed
876 source code.
878 .next
879 Many people have contributed code fragments, some large, some small, that were
880 not covered by any specific license requirements. It is assumed that the
881 contributors are happy to see their code incorporated into Exim under the GPL.
882 .endlist
888 . ////////////////////////////////////////////////////////////////////////////
889 . ////////////////////////////////////////////////////////////////////////////
891 .chapter "How Exim receives and delivers mail" "CHID11" &&&
892 "Receiving and delivering mail"
895 .section "Overall philosophy" "SECID10"
896 .cindex "design philosophy"
897 Exim is designed to work efficiently on systems that are permanently connected
898 to the Internet and are handling a general mix of mail. In such circumstances,
899 most messages can be delivered immediately. Consequently, Exim does not
900 maintain independent queues of messages for specific domains or hosts, though
901 it does try to send several messages in a single SMTP connection after a host
902 has been down, and it also maintains per-host retry information.
905 .section "Policy control" "SECID11"
906 .cindex "policy control" "overview"
907 Policy controls are now an important feature of MTAs that are connected to the
908 Internet. Perhaps their most important job is to stop MTAs from being abused as
909 &"open relays"& by misguided individuals who send out vast amounts of
910 unsolicited junk and want to disguise its source. Exim provides flexible
911 facilities for specifying policy controls on incoming mail:
913 .ilist
914 .cindex "&ACL;" "introduction"
915 Exim 4 (unlike previous versions of Exim) implements policy controls on
916 incoming mail by means of &'Access Control Lists'& (ACLs). Each list is a
917 series of statements that may either grant or deny access. ACLs can be used at
918 several places in the SMTP dialogue while receiving a message from a remote
919 host. However, the most common places are after each RCPT command, and at the
920 very end of the message. The sysadmin can specify conditions for accepting or
921 rejecting individual recipients or the entire message, respectively, at these
922 two points (see chapter &<<CHAPACL>>&). Denial of access results in an SMTP
923 error code.
924 .next
925 An ACL is also available for locally generated, non-SMTP messages. In this
926 case, the only available actions are to accept or deny the entire message.
927 .next
928 When Exim is compiled with the content-scanning extension, facilities are
929 provided in the ACL mechanism for passing the message to external virus and/or
930 spam scanning software. The result of such a scan is passed back to the ACL,
931 which can then use it to decide what to do with the message.
932 .next
933 When a message has been received, either from a remote host or from the local
934 host, but before the final acknowledgment has been sent, a locally supplied C
935 function called &[local_scan()]& can be run to inspect the message and decide
936 whether to accept it or not (see chapter &<<CHAPlocalscan>>&). If the message
937 is accepted, the list of recipients can be modified by the function.
938 .next
939 Using the &[local_scan()]& mechanism is another way of calling external scanner
940 software. The &%SA-Exim%& add-on package works this way. It does not require
941 Exim to be compiled with the content-scanning extension.
942 .next
943 After a message has been accepted, a further checking mechanism is available in
944 the form of the &'system filter'& (see chapter &<<CHAPsystemfilter>>&). This
945 runs at the start of every delivery process.
946 .endlist
950 .section "User filters" "SECID12"
951 .cindex "filter" "introduction"
952 .cindex "Sieve filter"
953 In a conventional Exim configuration, users are able to run private filters by
954 setting up appropriate &_.forward_& files in their home directories. See
955 chapter &<<CHAPredirect>>& (about the &(redirect)& router) for the
956 configuration needed to support this, and the separate document entitled
957 &'Exim's interfaces to mail filtering'& for user details. Two different kinds
958 of filtering are available:
960 .ilist
961 Sieve filters are written in the standard filtering language that is defined
962 by RFC 3028.
963 .next
964 Exim filters are written in a syntax that is unique to Exim, but which is more
965 powerful than Sieve, which it pre-dates.
966 .endlist
968 User filters are run as part of the routing process, described below.
972 .section "Message identification" "SECTmessiden"
973 .cindex "message ids" "details of format"
974 .cindex "format" "of message id"
975 .cindex "id of message"
976 .cindex "base62"
977 .cindex "base36"
978 .cindex "Darwin"
979 .cindex "Cygwin"
980 Every message handled by Exim is given a &'message id'& which is sixteen
981 characters long. It is divided into three parts, separated by hyphens, for
982 example &`16VDhn-0001bo-D3`&. Each part is a sequence of letters and digits,
983 normally encoding numbers in base 62. However, in the Darwin operating
984 system (Mac OS X) and when Exim is compiled to run under Cygwin, base 36
985 (avoiding the use of lower case letters) is used instead, because the message
986 id is used to construct filenames, and the names of files in those systems are
987 not always case-sensitive.
989 .cindex "pid (process id)" "re-use of"
990 The detail of the contents of the message id have changed as Exim has evolved.
991 Earlier versions relied on the operating system not re-using a process id (pid)
992 within one second. On modern operating systems, this assumption can no longer
993 be made, so the algorithm had to be changed. To retain backward compatibility,
994 the format of the message id was retained, which is why the following rules are
995 somewhat eccentric:
997 .ilist
998 The first six characters of the message id are the time at which the message
999 started to be received, to a granularity of one second. That is, this field
1000 contains the number of seconds since the start of the epoch (the normal Unix
1001 way of representing the date and time of day).
1002 .next
1003 After the first hyphen, the next six characters are the id of the process that
1004 received the message.
1005 .next
1006 There are two different possibilities for the final two characters:
1007 .olist
1008 .oindex "&%localhost_number%&"
1009 If &%localhost_number%& is not set, this value is the fractional part of the
1010 time of reception, normally in units of 1/2000 of a second, but for systems
1011 that must use base 36 instead of base 62 (because of case-insensitive file
1012 systems), the units are 1/1000 of a second.
1013 .next
1014 If &%localhost_number%& is set, it is multiplied by 200 (100) and added to
1015 the fractional part of the time, which in this case is in units of 1/200
1016 (1/100) of a second.
1017 .endlist
1018 .endlist
1020 After a message has been received, Exim waits for the clock to tick at the
1021 appropriate resolution before proceeding, so that if another message is
1022 received by the same process, or by another process with the same (re-used)
1023 pid, it is guaranteed that the time will be different. In most cases, the clock
1024 will already have ticked while the message was being received.
1027 .section "Receiving mail" "SECID13"
1028 .cindex "receiving mail"
1029 .cindex "message" "reception"
1030 The only way Exim can receive mail from another host is using SMTP over
1031 TCP/IP, in which case the sender and recipient addresses are transferred using
1032 SMTP commands. However, from a locally running process (such as a user's MUA),
1033 there are several possibilities:
1035 .ilist
1036 If the process runs Exim with the &%-bm%& option, the message is read
1037 non-interactively (usually via a pipe), with the recipients taken from the
1038 command line, or from the body of the message if &%-t%& is also used.
1039 .next
1040 If the process runs Exim with the &%-bS%& option, the message is also read
1041 non-interactively, but in this case the recipients are listed at the start of
1042 the message in a series of SMTP RCPT commands, terminated by a DATA
1043 command. This is called &"batch SMTP"& format,
1044 but it isn't really SMTP. The SMTP commands are just another way of passing
1045 envelope addresses in a non-interactive submission.
1046 .next
1047 If the process runs Exim with the &%-bs%& option, the message is read
1048 interactively, using the SMTP protocol. A two-way pipe is normally used for
1049 passing data between the local process and the Exim process.
1050 This is &"real"& SMTP and is handled in the same way as SMTP over TCP/IP. For
1051 example, the ACLs for SMTP commands are used for this form of submission.
1052 .next
1053 A local process may also make a TCP/IP call to the host's loopback address
1054 ( or any other of its IP addresses. When receiving messages, Exim
1055 does not treat the loopback address specially. It treats all such connections
1056 in the same way as connections from other hosts.
1057 .endlist
1060 .cindex "message sender, constructed by Exim"
1061 .cindex "sender" "constructed by Exim"
1062 In the three cases that do not involve TCP/IP, the sender address is
1063 constructed from the login name of the user that called Exim and a default
1064 qualification domain (which can be set by the &%qualify_domain%& configuration
1065 option). For local or batch SMTP, a sender address that is passed using the
1066 SMTP MAIL command is ignored. However, the system administrator may allow
1067 certain users (&"trusted users"&) to specify a different sender addresses
1068 unconditionally, or all users to specify certain forms of different sender
1069 address. The &%-f%& option or the SMTP MAIL command is used to specify these
1070 different addresses. See section &<<SECTtrustedadmin>>& for details of trusted
1071 users, and the &%untrusted_set_sender%& option for a way of allowing untrusted
1072 users to change sender addresses.
1074 Messages received by either of the non-interactive mechanisms are subject to
1075 checking by the non-SMTP ACL if one is defined. Messages received using SMTP
1076 (either over TCP/IP or interacting with a local process) can be checked by a
1077 number of ACLs that operate at different times during the SMTP session. Either
1078 individual recipients or the entire message can be rejected if local policy
1079 requirements are not met. The &[local_scan()]& function (see chapter
1080 &<<CHAPlocalscan>>&) is run for all incoming messages.
1082 Exim can be configured not to start a delivery process when a message is
1083 received; this can be unconditional, or depend on the number of incoming SMTP
1084 connections or the system load. In these situations, new messages wait on the
1085 queue until a queue runner process picks them up. However, in standard
1086 configurations under normal conditions, delivery is started as soon as a
1087 message is received.
1093 .section "Handling an incoming message" "SECID14"
1094 .cindex "spool directory" "files that hold a message"
1095 .cindex "file" "how a message is held"
1096 When Exim accepts a message, it writes two files in its spool directory. The
1097 first contains the envelope information, the current status of the message, and
1098 the header lines, and the second contains the body of the message. The names of
1099 the two spool files consist of the message id, followed by &`-H`& for the
1100 file containing the envelope and header, and &`-D`& for the data file.
1102 .cindex "spool directory" "&_input_& sub-directory"
1103 By default, all these message files are held in a single directory called
1104 &_input_& inside the general Exim spool directory. Some operating systems do
1105 not perform very well if the number of files in a directory gets large; to
1106 improve performance in such cases, the &%split_spool_directory%& option can be
1107 used. This causes Exim to split up the input files into 62 sub-directories
1108 whose names are single letters or digits. When this is done, the queue is
1109 processed one sub-directory at a time instead of all at once, which can improve
1110 overall performance even when there are not enough files in each directory to
1111 affect file system performance.
1113 The envelope information consists of the address of the message's sender and
1114 the addresses of the recipients. This information is entirely separate from
1115 any addresses contained in the header lines. The status of the message includes
1116 a list of recipients who have already received the message. The format of the
1117 first spool file is described in chapter &<<CHAPspool>>&.
1119 .cindex "rewriting" "addresses"
1120 Address rewriting that is specified in the rewrite section of the configuration
1121 (see chapter &<<CHAPrewrite>>&) is done once and for all on incoming addresses,
1122 both in the header lines and the envelope, at the time the message is accepted.
1123 If during the course of delivery additional addresses are generated (for
1124 example, via aliasing), these new addresses are rewritten as soon as they are
1125 generated. At the time a message is actually delivered (transported) further
1126 rewriting can take place; because this is a transport option, it can be
1127 different for different forms of delivery. It is also possible to specify the
1128 addition or removal of certain header lines at the time the message is
1129 delivered (see chapters &<<CHAProutergeneric>>& and
1130 &<<CHAPtransportgeneric>>&).
1134 .section "Life of a message" "SECID15"
1135 .cindex "message" "life of"
1136 .cindex "message" "frozen"
1137 A message remains in the spool directory until it is completely delivered to
1138 its recipients or to an error address, or until it is deleted by an
1139 administrator or by the user who originally created it. In cases when delivery
1140 cannot proceed &-- for example when a message can neither be delivered to its
1141 recipients nor returned to its sender, the message is marked &"frozen"& on the
1142 spool, and no more deliveries are attempted.
1144 .cindex "frozen messages" "thawing"
1145 .cindex "message" "thawing frozen"
1146 An administrator can &"thaw"& such messages when the problem has been
1147 corrected, and can also freeze individual messages by hand if necessary. In
1148 addition, an administrator can force a delivery error, causing a bounce message
1149 to be sent.
1151 .oindex "&%timeout_frozen_after%&"
1152 .oindex "&%ignore_bounce_errors_after%&"
1153 There are options called &%ignore_bounce_errors_after%& and
1154 &%timeout_frozen_after%&, which discard frozen messages after a certain time.
1155 The first applies only to frozen bounces, the second to all frozen messages.
1157 .cindex "message" "log file for"
1158 .cindex "log" "file for each message"
1159 While Exim is working on a message, it writes information about each delivery
1160 attempt to its main log file. This includes successful, unsuccessful, and
1161 delayed deliveries for each recipient (see chapter &<<CHAPlog>>&). The log
1162 lines are also written to a separate &'message log'& file for each message.
1163 These logs are solely for the benefit of the administrator and are normally
1164 deleted along with the spool files when processing of a message is complete.
1165 The use of individual message logs can be disabled by setting
1166 &%no_message_logs%&; this might give an improvement in performance on very busy
1167 systems.
1169 .cindex "journal file"
1170 .cindex "file" "journal"
1171 All the information Exim itself needs to set up a delivery is kept in the first
1172 spool file, along with the header lines. When a successful delivery occurs, the
1173 address is immediately written at the end of a journal file, whose name is the
1174 message id followed by &`-J`&. At the end of a delivery run, if there are some
1175 addresses left to be tried again later, the first spool file (the &`-H`& file)
1176 is updated to indicate which these are, and the journal file is then deleted.
1177 Updating the spool file is done by writing a new file and renaming it, to
1178 minimize the possibility of data loss.
1180 Should the system or Exim crash after a successful delivery but before
1181 the spool file has been updated, the journal is left lying around. The next
1182 time Exim attempts to deliver the message, it reads the journal file and
1183 updates the spool file before proceeding. This minimizes the chances of double
1184 deliveries caused by crashes.
1188 .section "Processing an address for delivery" "SECTprocaddress"
1189 .cindex "drivers" "definition of"
1190 .cindex "router" "definition of"
1191 .cindex "transport" "definition of"
1192 The main delivery processing elements of Exim are called &'routers'& and
1193 &'transports'&, and collectively these are known as &'drivers'&. Code for a
1194 number of them is provided in the source distribution, and compile-time options
1195 specify which ones are included in the binary. Runtime options specify which
1196 ones are actually used for delivering messages.
1198 .cindex "drivers" "instance definition"
1199 Each driver that is specified in the runtime configuration is an &'instance'&
1200 of that particular driver type. Multiple instances are allowed; for example,
1201 you can set up several different &(smtp)& transports, each with different
1202 option values that might specify different ports or different timeouts. Each
1203 instance has its own identifying name. In what follows we will normally use the
1204 instance name when discussing one particular instance (that is, one specific
1205 configuration of the driver), and the generic driver name when discussing
1206 the driver's features in general.
1208 A &'router'& is a driver that operates on an address, either determining how
1209 its delivery should happen, by assigning it to a specific transport, or
1210 converting the address into one or more new addresses (for example, via an
1211 alias file). A router may also explicitly choose to fail an address, causing it
1212 to be bounced.
1214 A &'transport'& is a driver that transmits a copy of the message from Exim's
1215 spool to some destination. There are two kinds of transport: for a &'local'&
1216 transport, the destination is a file or a pipe on the local host, whereas for a
1217 &'remote'& transport the destination is some other host. A message is passed
1218 to a specific transport as a result of successful routing. If a message has
1219 several recipients, it may be passed to a number of different transports.
1221 .cindex "preconditions" "definition of"
1222 An address is processed by passing it to each configured router instance in
1223 turn, subject to certain preconditions, until a router accepts the address or
1224 specifies that it should be bounced. We will describe this process in more
1225 detail shortly. First, as a simple example, we consider how each recipient
1226 address in a message is processed in a small configuration of three routers.
1228 To make this a more concrete example, it is described in terms of some actual
1229 routers, but remember, this is only an example. You can configure Exim's
1230 routers in many different ways, and there may be any number of routers in a
1231 configuration.
1233 The first router that is specified in a configuration is often one that handles
1234 addresses in domains that are not recognized specifically by the local host.
1235 Typically these are addresses for arbitrary domains on the Internet. A precondition
1236 is set up which looks for the special domains known to the host (for example,
1237 its own domain name), and the router is run for addresses that do &'not'&
1238 match. Typically, this is a router that looks up domains in the DNS in order to
1239 find the hosts to which this address routes. If it succeeds, the address is
1240 assigned to a suitable SMTP transport; if it does not succeed, the router is
1241 configured to fail the address.
1243 The second router is reached only when the domain is recognized as one that
1244 &"belongs"& to the local host. This router does redirection &-- also known as
1245 aliasing and forwarding. When it generates one or more new addresses from the
1246 original, each of them is routed independently from the start. Otherwise, the
1247 router may cause an address to fail, or it may simply decline to handle the
1248 address, in which case the address is passed to the next router.
1250 The final router in many configurations is one that checks to see if the
1251 address belongs to a local mailbox. The precondition may involve a check to
1252 see if the local part is the name of a login account, or it may look up the
1253 local part in a file or a database. If its preconditions are not met, or if
1254 the router declines, we have reached the end of the routers. When this happens,
1255 the address is bounced.
1259 .section "Processing an address for verification" "SECID16"
1260 .cindex "router" "for verification"
1261 .cindex "verifying address" "overview"
1262 As well as being used to decide how to deliver to an address, Exim's routers
1263 are also used for &'address verification'&. Verification can be requested as
1264 one of the checks to be performed in an ACL for incoming messages, on both
1265 sender and recipient addresses, and it can be tested using the &%-bv%& and
1266 &%-bvs%& command line options.
1268 When an address is being verified, the routers are run in &"verify mode"&. This
1269 does not affect the way the routers work, but it is a state that can be
1270 detected. By this means, a router can be skipped or made to behave differently
1271 when verifying. A common example is a configuration in which the first router
1272 sends all messages to a message-scanning program unless they have been
1273 previously scanned. Thus, the first router accepts all addresses without any
1274 checking, making it useless for verifying. Normally, the &%no_verify%& option
1275 would be set for such a router, causing it to be skipped in verify mode.
1280 .section "Running an individual router" "SECTrunindrou"
1281 .cindex "router" "running details"
1282 .cindex "preconditions" "checking"
1283 .cindex "router" "result of running"
1284 As explained in the example above, a number of preconditions are checked before
1285 running a router. If any are not met, the router is skipped, and the address is
1286 passed to the next router. When all the preconditions on a router &'are'& met,
1287 the router is run. What happens next depends on the outcome, which is one of
1288 the following:
1290 .ilist
1291 &'accept'&: The router accepts the address, and either assigns it to a
1292 transport or generates one or more &"child"& addresses. Processing the
1293 original address ceases
1294 .oindex "&%unseen%&"
1295 unless the &%unseen%& option is set on the router. This option
1296 can be used to set up multiple deliveries with different routing (for example,
1297 for keeping archive copies of messages). When &%unseen%& is set, the address is
1298 passed to the next router. Normally, however, an &'accept'& return marks the
1299 end of routing.
1301 Any child addresses generated by the router are processed independently,
1302 starting with the first router by default. It is possible to change this by
1303 setting the &%redirect_router%& option to specify which router to start at for
1304 child addresses. Unlike &%pass_router%& (see below) the router specified by
1305 &%redirect_router%& may be anywhere in the router configuration.
1306 .next
1307 &'pass'&: The router recognizes the address, but cannot handle it itself. It
1308 requests that the address be passed to another router. By default, the address
1309 is passed to the next router, but this can be changed by setting the
1310 &%pass_router%& option. However, (unlike &%redirect_router%&) the named router
1311 must be below the current router (to avoid loops).
1312 .next
1313 &'decline'&: The router declines to accept the address because it does not
1314 recognize it at all. By default, the address is passed to the next router, but
1315 this can be prevented by setting the &%no_more%& option. When &%no_more%& is
1316 set, all the remaining routers are skipped. In effect, &%no_more%& converts
1317 &'decline'& into &'fail'&.
1318 .next
1319 &'fail'&: The router determines that the address should fail, and queues it for
1320 the generation of a bounce message. There is no further processing of the
1321 original address unless &%unseen%& is set on the router.
1322 .next
1323 &'defer'&: The router cannot handle the address at the present time. (A
1324 database may be offline, or a DNS lookup may have timed out.) No further
1325 processing of the address happens in this delivery attempt. It is tried again
1326 next time the message is considered for delivery.
1327 .next
1328 &'error'&: There is some error in the router (for example, a syntax error in
1329 its configuration). The action is as for defer.
1330 .endlist
1332 If an address reaches the end of the routers without having been accepted by
1333 any of them, it is bounced as unrouteable. The default error message in this
1334 situation is &"unrouteable address"&, but you can set your own message by
1335 making use of the &%cannot_route_message%& option. This can be set for any
1336 router; the value from the last router that &"saw"& the address is used.
1338 Sometimes while routing you want to fail a delivery when some conditions are
1339 met but others are not, instead of passing the address on for further routing.
1340 You can do this by having a second router that explicitly fails the delivery
1341 when the relevant conditions are met. The &(redirect)& router has a &"fail"&
1342 facility for this purpose.
1345 .section "Duplicate addresses" "SECID17"
1346 .cindex "case of local parts"
1347 .cindex "address duplicate, discarding"
1348 .cindex "duplicate addresses"
1349 Once routing is complete, Exim scans the addresses that are assigned to local
1350 and remote transports and discards any duplicates that it finds. During this
1351 check, local parts are treated case-sensitively. This happens only when
1352 actually delivering a message; when testing routers with &%-bt%&, all the
1353 routed addresses are shown.
1357 .section "Router preconditions" "SECTrouprecon"
1358 .cindex "router" "preconditions, order of processing"
1359 .cindex "preconditions" "order of processing"
1360 The preconditions that are tested for each router are listed below, in the
1361 order in which they are tested. The individual configuration options are
1362 described in more detail in chapter &<<CHAProutergeneric>>&.
1364 .ilist
1365 .cindex affix "router precondition"
1366 The &%local_part_prefix%& and &%local_part_suffix%& options can specify that
1367 the local parts handled by the router may or must have certain prefixes and/or
1368 suffixes. If a mandatory affix (prefix or suffix) is not present, the router is
1369 skipped. These conditions are tested first. When an affix is present, it is
1370 removed from the local part before further processing, including the evaluation
1371 of any other conditions.
1372 .next
1373 Routers can be designated for use only when not verifying an address, that is,
1374 only when routing it for delivery (or testing its delivery routing). If the
1375 &%verify%& option is set false, the router is skipped when Exim is verifying an
1376 address.
1377 Setting the &%verify%& option actually sets two options, &%verify_sender%& and
1378 &%verify_recipient%&, which independently control the use of the router for
1379 sender and recipient verification. You can set these options directly if
1380 you want a router to be used for only one type of verification.
1381 Note that cutthrough delivery is classed as a recipient verification for this purpose.
1382 .next
1383 If the &%address_test%& option is set false, the router is skipped when Exim is
1384 run with the &%-bt%& option to test an address routing. This can be helpful
1385 when the first router sends all new messages to a scanner of some sort; it
1386 makes it possible to use &%-bt%& to test subsequent delivery routing without
1387 having to simulate the effect of the scanner.
1388 .next
1389 Routers can be designated for use only when verifying an address, as
1390 opposed to routing it for delivery. The &%verify_only%& option controls this.
1391 Again, cutthrough delivery counts as a verification.
1392 .next
1393 Individual routers can be explicitly skipped when running the routers to
1394 check an address given in the SMTP EXPN command (see the &%expn%& option).
1395 .next
1396 If the &%domains%& option is set, the domain of the address must be in the set
1397 of domains that it defines.
1398 .next
1399 .vindex "&$local_part_prefix$&"
1400 .vindex "&$local_part$&"
1401 .vindex "&$local_part_suffix$&"
1402 .cindex affix "router precondition"
1403 If the &%local_parts%& option is set, the local part of the address must be in
1404 the set of local parts that it defines. If &%local_part_prefix%& or
1405 &%local_part_suffix%& is in use, the prefix or suffix is removed from the local
1406 part before this check. If you want to do precondition tests on local parts
1407 that include affixes, you can do so by using a &%condition%& option (see below)
1408 that uses the variables &$local_part$&, &$local_part_prefix$&, and
1409 &$local_part_suffix$& as necessary.
1410 .next
1411 .vindex "&$local_user_uid$&"
1412 .vindex "&$local_user_gid$&"
1413 .vindex "&$home$&"
1414 If the &%check_local_user%& option is set, the local part must be the name of
1415 an account on the local host. If this check succeeds, the uid and gid of the
1416 local user are placed in &$local_user_uid$& and &$local_user_gid$& and the
1417 user's home directory is placed in &$home$&; these values can be used in the
1418 remaining preconditions.
1419 .next
1420 If the &%router_home_directory%& option is set, it is expanded at this point,
1421 because it overrides the value of &$home$&. If this expansion were left till
1422 later, the value of &$home$& as set by &%check_local_user%& would be used in
1423 subsequent tests. Having two different values of &$home$& in the same router
1424 could lead to confusion.
1425 .next
1426 If the &%senders%& option is set, the envelope sender address must be in the
1427 set of addresses that it defines.
1428 .next
1429 If the &%require_files%& option is set, the existence or non-existence of
1430 specified files is tested.
1431 .next
1432 .cindex "customizing" "precondition"
1433 If the &%condition%& option is set, it is evaluated and tested. This option
1434 uses an expanded string to allow you to set up your own custom preconditions.
1435 Expanded strings are described in chapter &<<CHAPexpand>>&.
1436 .endlist
1439 Note that &%require_files%& comes near the end of the list, so you cannot use
1440 it to check for the existence of a file in which to lookup up a domain, local
1441 part, or sender. However, as these options are all expanded, you can use the
1442 &%exists%& expansion condition to make such tests within each condition. The
1443 &%require_files%& option is intended for checking files that the router may be
1444 going to use internally, or which are needed by a specific transport (for
1445 example, &_.procmailrc_&).
1449 .section "Delivery in detail" "SECID18"
1450 .cindex "delivery" "in detail"
1451 When a message is to be delivered, the sequence of events is as follows:
1453 .ilist
1454 If a system-wide filter file is specified, the message is passed to it. The
1455 filter may add recipients to the message, replace the recipients, discard the
1456 message, cause a new message to be generated, or cause the message delivery to
1457 fail. The format of the system filter file is the same as for Exim user filter
1458 files, described in the separate document entitled &'Exim's interfaces to mail
1459 filtering'&.
1460 .cindex "Sieve filter" "not available for system filter"
1461 (&*Note*&: Sieve cannot be used for system filter files.)
1463 Some additional features are available in system filters &-- see chapter
1464 &<<CHAPsystemfilter>>& for details. Note that a message is passed to the system
1465 filter only once per delivery attempt, however many recipients it has. However,
1466 if there are several delivery attempts because one or more addresses could not
1467 be immediately delivered, the system filter is run each time. The filter
1468 condition &%first_delivery%& can be used to detect the first run of the system
1469 filter.
1470 .next
1471 Each recipient address is offered to each configured router, in turn, subject to
1472 its preconditions, until one is able to handle it. If no router can handle the
1473 address, that is, if they all decline, the address is failed. Because routers
1474 can be targeted at particular domains, several locally handled domains can be
1475 processed entirely independently of each other.
1476 .next
1477 .cindex "routing" "loops in"
1478 .cindex "loop" "while routing"
1479 A router that accepts an address may assign it to a local or a remote
1480 transport. However, the transport is not run at this time. Instead, the address
1481 is placed on a list for the particular transport, which will be run later.
1482 Alternatively, the router may generate one or more new addresses (typically
1483 from alias, forward, or filter files). New addresses are fed back into this
1484 process from the top, but in order to avoid loops, a router ignores any address
1485 which has an identically-named ancestor that was processed by itself.
1486 .next
1487 When all the routing has been done, addresses that have been successfully
1488 handled are passed to their assigned transports. When local transports are
1489 doing real local deliveries, they handle only one address at a time, but if a
1490 local transport is being used as a pseudo-remote transport (for example, to
1491 collect batched SMTP messages for transmission by some other means) multiple
1492 addresses can be handled. Remote transports can always handle more than one
1493 address at a time, but can be configured not to do so, or to restrict multiple
1494 addresses to the same domain.
1495 .next
1496 Each local delivery to a file or a pipe runs in a separate process under a
1497 non-privileged uid, and these deliveries are run one at a time. Remote
1498 deliveries also run in separate processes, normally under a uid that is private
1499 to Exim (&"the Exim user"&), but in this case, several remote deliveries can be
1500 run in parallel. The maximum number of simultaneous remote deliveries for any
1501 one message is set by the &%remote_max_parallel%& option.
1502 The order in which deliveries are done is not defined, except that all local
1503 deliveries happen before any remote deliveries.
1504 .next
1505 .cindex "queue runner"
1506 When it encounters a local delivery during a queue run, Exim checks its retry
1507 database to see if there has been a previous temporary delivery failure for the
1508 address before running the local transport. If there was a previous failure,
1509 Exim does not attempt a new delivery until the retry time for the address is
1510 reached. However, this happens only for delivery attempts that are part of a
1511 queue run. Local deliveries are always attempted when delivery immediately
1512 follows message reception, even if retry times are set for them. This makes for
1513 better behaviour if one particular message is causing problems (for example,
1514 causing quota overflow, or provoking an error in a filter file).
1515 .next
1516 .cindex "delivery" "retry in remote transports"
1517 Remote transports do their own retry handling, since an address may be
1518 deliverable to one of a number of hosts, each of which may have a different
1519 retry time. If there have been previous temporary failures and no host has
1520 reached its retry time, no delivery is attempted, whether in a queue run or
1521 not. See chapter &<<CHAPretry>>& for details of retry strategies.
1522 .next
1523 If there were any permanent errors, a bounce message is returned to an
1524 appropriate address (the sender in the common case), with details of the error
1525 for each failing address. Exim can be configured to send copies of bounce
1526 messages to other addresses.
1527 .next
1528 .cindex "delivery" "deferral"
1529 If one or more addresses suffered a temporary failure, the message is left on
1530 the queue, to be tried again later. Delivery of these addresses is said to be
1531 &'deferred'&.
1532 .next
1533 When all the recipient addresses have either been delivered or bounced,
1534 handling of the message is complete. The spool files and message log are
1535 deleted, though the message log can optionally be preserved if required.
1536 .endlist
1541 .section "Retry mechanism" "SECID19"
1542 .cindex "delivery" "retry mechanism"
1543 .cindex "retry" "description of mechanism"
1544 .cindex "queue runner"
1545 Exim's mechanism for retrying messages that fail to get delivered at the first
1546 attempt is the queue runner process. You must either run an Exim daemon that
1547 uses the &%-q%& option with a time interval to start queue runners at regular
1548 intervals or use some other means (such as &'cron'&) to start them. If you do
1549 not arrange for queue runners to be run, messages that fail temporarily at the
1550 first attempt will remain in your queue forever. A queue runner process works
1551 its way through the queue, one message at a time, trying each delivery that has
1552 passed its retry time.
1553 You can run several queue runners at once.
1555 Exim uses a set of configured rules to determine when next to retry the failing
1556 address (see chapter &<<CHAPretry>>&). These rules also specify when Exim
1557 should give up trying to deliver to the address, at which point it generates a
1558 bounce message. If no retry rules are set for a particular host, address, and
1559 error combination, no retries are attempted, and temporary errors are treated
1560 as permanent.
1564 .section "Temporary delivery failure" "SECID20"
1565 .cindex "delivery" "temporary failure"
1566 There are many reasons why a message may not be immediately deliverable to a
1567 particular address. Failure to connect to a remote machine (because it, or the
1568 connection to it, is down) is one of the most common. Temporary failures may be
1569 detected during routing as well as during the transport stage of delivery.
1570 Local deliveries may be delayed if NFS files are unavailable, or if a mailbox
1571 is on a file system where the user is over quota. Exim can be configured to
1572 impose its own quotas on local mailboxes; where system quotas are set they will
1573 also apply.
1575 If a host is unreachable for a period of time, a number of messages may be
1576 waiting for it by the time it recovers, and sending them in a single SMTP
1577 connection is clearly beneficial. Whenever a delivery to a remote host is
1578 deferred,
1579 .cindex "hints database" "deferred deliveries"
1580 Exim makes a note in its hints database, and whenever a successful
1581 SMTP delivery has happened, it looks to see if any other messages are waiting
1582 for the same host. If any are found, they are sent over the same SMTP
1583 connection, subject to a configuration limit as to the maximum number in any
1584 one connection.
1588 .section "Permanent delivery failure" "SECID21"
1589 .cindex "delivery" "permanent failure"
1590 .cindex "bounce message" "when generated"
1591 When a message cannot be delivered to some or all of its intended recipients, a
1592 bounce message is generated. Temporary delivery failures turn into permanent
1593 errors when their timeout expires. All the addresses that fail in a given
1594 delivery attempt are listed in a single message. If the original message has
1595 many recipients, it is possible for some addresses to fail in one delivery
1596 attempt and others to fail subsequently, giving rise to more than one bounce
1597 message. The wording of bounce messages can be customized by the administrator.
1598 See chapter &<<CHAPemsgcust>>& for details.
1600 .cindex "&'X-Failed-Recipients:'& header line"
1601 Bounce messages contain an &'X-Failed-Recipients:'& header line that lists the
1602 failed addresses, for the benefit of programs that try to analyse such messages
1603 automatically.
1605 .cindex "bounce message" "recipient of"
1606 A bounce message is normally sent to the sender of the original message, as
1607 obtained from the message's envelope. For incoming SMTP messages, this is the
1608 address given in the MAIL command. However, when an address is expanded via a
1609 forward or alias file, an alternative address can be specified for delivery
1610 failures of the generated addresses. For a mailing list expansion (see section
1611 &<<SECTmailinglists>>&) it is common to direct bounce messages to the manager
1612 of the list.
1616 .section "Failures to deliver bounce messages" "SECID22"
1617 .cindex "bounce message" "failure to deliver"
1618 If a bounce message (either locally generated or received from a remote host)
1619 itself suffers a permanent delivery failure, the message is left in the queue,
1620 but it is frozen, awaiting the attention of an administrator. There are options
1621 that can be used to make Exim discard such failed messages, or to keep them
1622 for only a short time (see &%timeout_frozen_after%& and
1623 &%ignore_bounce_errors_after%&).
1629 . ////////////////////////////////////////////////////////////////////////////
1630 . ////////////////////////////////////////////////////////////////////////////
1632 .chapter "Building and installing Exim" "CHID3"
1633 .scindex IIDbuex "building Exim"
1635 .section "Unpacking" "SECID23"
1636 Exim is distributed as a gzipped or bzipped tar file which, when unpacked,
1637 creates a directory with the name of the current release (for example,
1638 &_exim-&version()_&) into which the following files are placed:
1640 .table2 140pt
1641 .irow &_ACKNOWLEDGMENTS_& "contains some acknowledgments"
1642 .irow &_CHANGES_& "contains a reference to where changes are &&&
1643 documented"
1644 .irow &_LICENCE_& "the GNU General Public Licence"
1645 .irow &_Makefile_& "top-level make file"
1646 .irow &_NOTICE_& "conditions for the use of Exim"
1647 .irow &_README_& "list of files, directories and simple build &&&
1648 instructions"
1649 .endtable
1651 Other files whose names begin with &_README_& may also be present. The
1652 following subdirectories are created:
1654 .table2 140pt
1655 .irow &_Local_& "an empty directory for local configuration files"
1656 .irow &_OS_& "OS-specific files"
1657 .irow &_doc_& "documentation files"
1658 .irow &_exim_monitor_& "source files for the Exim monitor"
1659 .irow &_scripts_& "scripts used in the build process"
1660 .irow &_src_& "remaining source files"
1661 .irow &_util_& "independent utilities"
1662 .endtable
1664 The main utility programs are contained in the &_src_& directory and are built
1665 with the Exim binary. The &_util_& directory contains a few optional scripts
1666 that may be useful to some sites.
1669 .section "Multiple machine architectures and operating systems" "SECID24"
1670 .cindex "building Exim" "multiple OS/architectures"
1671 The building process for Exim is arranged to make it easy to build binaries for
1672 a number of different architectures and operating systems from the same set of
1673 source files. Compilation does not take place in the &_src_& directory.
1674 Instead, a &'build directory'& is created for each architecture and operating
1675 system.
1676 .cindex "symbolic link" "to build directory"
1677 Symbolic links to the sources are installed in this directory, which is where
1678 the actual building takes place. In most cases, Exim can discover the machine
1679 architecture and operating system for itself, but the defaults can be
1680 overridden if necessary.
1681 .cindex compiler requirements
1682 .cindex compiler version
1683 A C99-capable compiler will be required for the build.
1686 .section "PCRE library" "SECTpcre"
1687 .cindex "PCRE library"
1688 Exim no longer has an embedded PCRE library as the vast majority of
1689 modern systems include PCRE as a system library, although you may need to
1690 install the PCRE package or the PCRE development package for your operating
1691 system. If your system has a normal PCRE installation the Exim build
1692 process will need no further configuration. If the library or the
1693 headers are in an unusual location you will need to either set the PCRE_LIBS
1694 and INCLUDE directives appropriately,
1695 or set PCRE_CONFIG=yes to use the installed &(pcre-config)& command.
1696 If your operating system has no
1697 PCRE support then you will need to obtain and build the current PCRE
1698 from &url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/).
1699 More information on PCRE is available at &url(https://www.pcre.org/).
1701 .section "DBM libraries" "SECTdb"
1702 .cindex "DBM libraries" "discussion of"
1703 .cindex "hints database" "DBM files used for"
1704 Even if you do not use any DBM files in your configuration, Exim still needs a
1705 DBM library in order to operate, because it uses indexed files for its hints
1706 databases. Unfortunately, there are a number of DBM libraries in existence, and
1707 different operating systems often have different ones installed.
1709 .cindex "Solaris" "DBM library for"
1710 .cindex "IRIX, DBM library for"
1711 .cindex "BSD, DBM library for"
1712 .cindex "Linux, DBM library for"
1713 If you are using Solaris, IRIX, one of the modern BSD systems, or a modern
1714 Linux distribution, the DBM configuration should happen automatically, and you
1715 may be able to ignore this section. Otherwise, you may have to learn more than
1716 you would like about DBM libraries from what follows.
1718 .cindex "&'ndbm'& DBM library"
1719 Licensed versions of Unix normally contain a library of DBM functions operating
1720 via the &'ndbm'& interface, and this is what Exim expects by default. Free
1721 versions of Unix seem to vary in what they contain as standard. In particular,
1722 some early versions of Linux have no default DBM library, and different
1723 distributors have chosen to bundle different libraries with their packaged
1724 versions. However, the more recent releases seem to have standardized on the
1725 Berkeley DB library.
1727 Different DBM libraries have different conventions for naming the files they
1728 use. When a program opens a file called &_dbmfile_&, there are several
1729 possibilities:
1731 .olist
1732 A traditional &'ndbm'& implementation, such as that supplied as part of
1733 Solaris, operates on two files called &_dbmfile.dir_& and &_dbmfile.pag_&.
1734 .next
1735 .cindex "&'gdbm'& DBM library"
1736 The GNU library, &'gdbm'&, operates on a single file. If used via its &'ndbm'&
1737 compatibility interface it makes two different hard links to it with names
1738 &_dbmfile.dir_& and &_dbmfile.pag_&, but if used via its native interface, the
1739 filename is used unmodified.
1740 .next
1741 .cindex "Berkeley DB library"
1742 The Berkeley DB package, if called via its &'ndbm'& compatibility interface,
1743 operates on a single file called &_dbmfile.db_&, but otherwise looks to the
1744 programmer exactly the same as the traditional &'ndbm'& implementation.
1745 .next
1746 If the Berkeley package is used in its native mode, it operates on a single
1747 file called &_dbmfile_&; the programmer's interface is somewhat different to
1748 the traditional &'ndbm'& interface.
1749 .next
1750 To complicate things further, there are several very different versions of the
1751 Berkeley DB package. Version 1.85 was stable for a very long time, releases
1752 2.&'x'& and 3.&'x'& were current for a while, but the latest versions when Exim last revamped support were numbered 4.&'x'&.
1753 Maintenance of some of the earlier releases has ceased. All versions of
1754 Berkeley DB could be obtained from
1755 &url(http://www.sleepycat.com/), which is now a redirect to their new owner's
1756 page with far newer versions listed.
1757 It is probably wise to plan to move your storage configurations away from
1758 Berkeley DB format, as today there are smaller and simpler alternatives more
1759 suited to Exim's usage model.
1760 .next
1761 .cindex "&'tdb'& DBM library"
1762 Yet another DBM library, called &'tdb'&, is available from
1763 &url(https://sourceforge.net/projects/tdb/files/). It has its own interface, and also
1764 operates on a single file.
1765 .endlist
1767 .cindex "USE_DB"
1768 .cindex "DBM libraries" "configuration for building"
1769 Exim and its utilities can be compiled to use any of these interfaces. In order
1770 to use any version of the Berkeley DB package in native mode, you must set
1771 USE_DB in an appropriate configuration file (typically
1772 &_Local/Makefile_&). For example:
1773 .code
1774 USE_DB=yes
1775 .endd
1776 Similarly, for gdbm you set USE_GDBM, and for tdb you set USE_TDB. An
1777 error is diagnosed if you set more than one of these.
1779 At the lowest level, the build-time configuration sets none of these options,
1780 thereby assuming an interface of type (1). However, some operating system
1781 configuration files (for example, those for the BSD operating systems and
1782 Linux) assume type (4) by setting USE_DB as their default, and the
1783 configuration files for Cygwin set USE_GDBM. Anything you set in
1784 &_Local/Makefile_&, however, overrides these system defaults.
1786 As well as setting USE_DB, USE_GDBM, or USE_TDB, it may also be
1787 necessary to set DBMLIB, to cause inclusion of the appropriate library, as
1788 in one of these lines:
1789 .code
1790 DBMLIB = -ldb
1791 DBMLIB = -ltdb
1792 .endd
1793 Settings like that will work if the DBM library is installed in the standard
1794 place. Sometimes it is not, and the library's header file may also not be in
1795 the default path. You may need to set INCLUDE to specify where the header
1796 file is, and to specify the path to the library more fully in DBMLIB, as in
1797 this example:
1798 .code
1799 INCLUDE=-I/usr/local/include/db-4.1
1800 DBMLIB=/usr/local/lib/db-4.1/libdb.a
1801 .endd
1802 There is further detailed discussion about the various DBM libraries in the
1803 file &_doc/dbm.discuss.txt_& in the Exim distribution.
1807 .section "Pre-building configuration" "SECID25"
1808 .cindex "building Exim" "pre-building configuration"
1809 .cindex "configuration for building Exim"
1810 .cindex "&_Local/Makefile_&"
1811 .cindex "&_src/EDITME_&"
1812 Before building Exim, a local configuration file that specifies options
1813 independent of any operating system has to be created with the name
1814 &_Local/Makefile_&. A template for this file is supplied as the file
1815 &_src/EDITME_&, and it contains full descriptions of all the option settings
1816 therein. These descriptions are therefore not repeated here. If you are
1817 building Exim for the first time, the simplest thing to do is to copy
1818 &_src/EDITME_& to &_Local/Makefile_&, then read it and edit it appropriately.
1820 There are three settings that you must supply, because Exim will not build
1821 without them. They are the location of the runtime configuration file
1822 (CONFIGURE_FILE), the directory in which Exim binaries will be installed
1823 (BIN_DIRECTORY), and the identity of the Exim user (EXIM_USER and
1824 maybe EXIM_GROUP as well). The value of CONFIGURE_FILE can in fact be
1825 a colon-separated list of filenames; Exim uses the first of them that exists.
1827 There are a few other parameters that can be specified either at build time or
1828 at runtime, to enable the same binary to be used on a number of different
1829 machines. However, if the locations of Exim's spool directory and log file
1830 directory (if not within the spool directory) are fixed, it is recommended that
1831 you specify them in &_Local/Makefile_& instead of at runtime, so that errors
1832 detected early in Exim's execution (such as a malformed configuration file) can
1833 be logged.
1835 .cindex "content scanning" "specifying at build time"
1836 Exim's interfaces for calling virus and spam scanning software directly from
1837 access control lists are not compiled by default. If you want to include these
1838 facilities, you need to set
1839 .code
1841 .endd
1842 in your &_Local/Makefile_&. For details of the facilities themselves, see
1843 chapter &<<CHAPexiscan>>&.
1846 .cindex "&_Local/eximon.conf_&"
1847 .cindex "&_exim_monitor/EDITME_&"
1848 If you are going to build the Exim monitor, a similar configuration process is
1849 required. The file &_exim_monitor/EDITME_& must be edited appropriately for
1850 your installation and saved under the name &_Local/eximon.conf_&. If you are
1851 happy with the default settings described in &_exim_monitor/EDITME_&,
1852 &_Local/eximon.conf_& can be empty, but it must exist.
1854 This is all the configuration that is needed in straightforward cases for known
1855 operating systems. However, the building process is set up so that it is easy
1856 to override options that are set by default or by operating-system-specific
1857 configuration files, for example, to change the C compiler, which
1858 defaults to &%gcc%&. See section &<<SECToverride>>& below for details of how to
1859 do this.
1863 .section "Support for iconv()" "SECID26"
1864 .cindex "&[iconv()]& support"
1865 .cindex "RFC 2047"
1866 The contents of header lines in messages may be encoded according to the rules
1867 described RFC 2047. This makes it possible to transmit characters that are not
1868 in the ASCII character set, and to label them as being in a particular
1869 character set. When Exim is inspecting header lines by means of the &%$h_%&
1870 mechanism, it decodes them, and translates them into a specified character set
1871 (default is set at build time). The translation is possible only if the operating system
1872 supports the &[iconv()]& function.
1874 However, some of the operating systems that supply &[iconv()]& do not support
1875 very many conversions. The GNU &%libiconv%& library (available from
1876 &url(https://www.gnu.org/software/libiconv/)) can be installed on such
1877 systems to remedy this deficiency, as well as on systems that do not supply
1878 &[iconv()]& at all. After installing &%libiconv%&, you should add
1879 .code
1880 HAVE_ICONV=yes
1881 .endd
1882 to your &_Local/Makefile_& and rebuild Exim.
1886 .section "Including TLS/SSL encryption support" "SECTinctlsssl"
1887 .cindex "TLS" "including support for TLS"
1888 .cindex "encryption" "including support for"
1889 .cindex "SUPPORT_TLS"
1890 .cindex "OpenSSL" "building Exim with"
1891 .cindex "GnuTLS" "building Exim with"
1892 Exim can be built to support encrypted SMTP connections, using the STARTTLS
1893 command as per RFC 2487. It can also support legacy clients that expect to
1894 start a TLS session immediately on connection to a non-standard port (see the
1895 &%tls_on_connect_ports%& runtime option and the &%-tls-on-connect%& command
1896 line option).
1898 If you want to build Exim with TLS support, you must first install either the
1899 OpenSSL or GnuTLS library. There is no cryptographic code in Exim itself for
1900 implementing SSL.
1902 If OpenSSL is installed, you should set
1903 .code
1904 SUPPORT_TLS=yes
1905 TLS_LIBS=-lssl -lcrypto
1906 .endd
1907 in &_Local/Makefile_&. You may also need to specify the locations of the
1908 OpenSSL library and include files. For example:
1909 .code
1910 SUPPORT_TLS=yes
1911 TLS_LIBS=-L/usr/local/openssl/lib -lssl -lcrypto
1912 TLS_INCLUDE=-I/usr/local/openssl/include/
1913 .endd
1914 .cindex "pkg-config" "OpenSSL"
1915 If you have &'pkg-config'& available, then instead you can just use:
1916 .code
1917 SUPPORT_TLS=yes
1918 USE_OPENSSL_PC=openssl
1919 .endd
1920 .cindex "USE_GNUTLS"
1921 If GnuTLS is installed, you should set
1922 .code
1923 SUPPORT_TLS=yes
1924 USE_GNUTLS=yes
1925 TLS_LIBS=-lgnutls -ltasn1 -lgcrypt
1926 .endd
1927 in &_Local/Makefile_&, and again you may need to specify the locations of the
1928 library and include files. For example:
1929 .code
1930 SUPPORT_TLS=yes
1931 USE_GNUTLS=yes
1932 TLS_LIBS=-L/usr/gnu/lib -lgnutls -ltasn1 -lgcrypt
1933 TLS_INCLUDE=-I/usr/gnu/include
1934 .endd
1935 .cindex "pkg-config" "GnuTLS"
1936 If you have &'pkg-config'& available, then instead you can just use:
1937 .code
1938 SUPPORT_TLS=yes
1939 USE_GNUTLS=yes
1940 USE_GNUTLS_PC=gnutls
1941 .endd
1943 You do not need to set TLS_INCLUDE if the relevant directory is already
1944 specified in INCLUDE. Details of how to configure Exim to make use of TLS are
1945 given in chapter &<<CHAPTLS>>&.
1950 .section "Use of tcpwrappers" "SECID27"
1952 .cindex "tcpwrappers, building Exim to support"
1953 .cindex "USE_TCP_WRAPPERS"
1955 .cindex "tcp_wrappers_daemon_name"
1956 Exim can be linked with the &'tcpwrappers'& library in order to check incoming
1957 SMTP calls using the &'tcpwrappers'& control files. This may be a convenient
1958 alternative to Exim's own checking facilities for installations that are
1959 already making use of &'tcpwrappers'& for other purposes. To do this, you
1960 should set USE_TCP_WRAPPERS in &_Local/Makefile_&, arrange for the file
1961 &_tcpd.h_& to be available at compile time, and also ensure that the library
1962 &_libwrap.a_& is available at link time, typically by including &%-lwrap%& in
1963 EXTRALIBS_EXIM. For example, if &'tcpwrappers'& is installed in &_/usr/local_&,
1964 you might have
1965 .code
1967 CFLAGS=-O -I/usr/local/include
1968 EXTRALIBS_EXIM=-L/usr/local/lib -lwrap
1969 .endd
1970 in &_Local/Makefile_&. The daemon name to use in the &'tcpwrappers'& control
1971 files is &"exim"&. For example, the line
1972 .code
1973 exim : LOCAL 192.168.1. .friendly.domain.example
1974 .endd
1975 in your &_/etc/hosts.allow_& file allows connections from the local host, from
1976 the subnet, and from all hosts in &'friendly.domain.example'&.
1977 All other connections are denied. The daemon name used by &'tcpwrappers'&
1978 can be changed at build time by setting TCP_WRAPPERS_DAEMON_NAME in
1979 &_Local/Makefile_&, or by setting tcp_wrappers_daemon_name in the
1980 configure file. Consult the &'tcpwrappers'& documentation for
1981 further details.
1984 .section "Including support for IPv6" "SECID28"
1985 .cindex "IPv6" "including support for"
1986 Exim contains code for use on systems that have IPv6 support. Setting
1987 &`HAVE_IPV6=YES`& in &_Local/Makefile_& causes the IPv6 code to be included;
1988 it may also be necessary to set IPV6_INCLUDE and IPV6_LIBS on systems
1989 where the IPv6 support is not fully integrated into the normal include and
1990 library files.
1992 Two different types of DNS record for handling IPv6 addresses have been
1993 defined. AAAA records (analogous to A records for IPv4) are in use, and are
1994 currently seen as the mainstream. Another record type called A6 was proposed
1995 as better than AAAA because it had more flexibility. However, it was felt to be
1996 over-complex, and its status was reduced to &"experimental"&.
1997 Exim used to
1998 have a compile option for including A6 record support but this has now been
1999 withdrawn.
2003 .section "Dynamically loaded lookup module support" "SECTdynamicmodules"
2004 .cindex "lookup modules"
2005 .cindex "dynamic modules"
2006 .cindex ".so building"
2007 On some platforms, Exim supports not compiling all lookup types directly into
2008 the main binary, instead putting some into external modules which can be loaded
2009 on demand.
2010 This permits packagers to build Exim with support for lookups with extensive
2011 library dependencies without requiring all users to install all of those
2012 dependencies.
2013 Most, but not all, lookup types can be built this way.
2015 Set &`LOOKUP_MODULE_DIR`& to the directory into which the modules will be
2016 installed; Exim will only load modules from that directory, as a security
2017 measure. You will need to set &`CFLAGS_DYNAMIC`& if not already defined
2018 for your OS; see &_OS/Makefile-Linux_& for an example.
2019 Some other requirements for adjusting &`EXTRALIBS`& may also be necessary,
2020 see &_src/EDITME_& for details.
2022 Then, for each module to be loaded dynamically, define the relevant
2023 &`LOOKUP_`&<&'lookup_type'&> flags to have the value "2" instead of "yes".
2024 For example, this will build in lsearch but load sqlite and mysql support
2025 on demand:
2026 .code
2030 .endd
2033 .section "The building process" "SECID29"
2034 .cindex "build directory"
2035 Once &_Local/Makefile_& (and &_Local/eximon.conf_&, if required) have been
2036 created, run &'make'& at the top level. It determines the architecture and
2037 operating system types, and creates a build directory if one does not exist.
2038 For example, on a Sun system running Solaris 8, the directory
2039 &_build-SunOS5-5.8-sparc_& is created.
2040 .cindex "symbolic link" "to source files"
2041 Symbolic links to relevant source files are installed in the build directory.
2043 If this is the first time &'make'& has been run, it calls a script that builds
2044 a make file inside the build directory, using the configuration files from the
2045 &_Local_& directory. The new make file is then passed to another instance of
2046 &'make'&. This does the real work, building a number of utility scripts, and
2047 then compiling and linking the binaries for the Exim monitor (if configured), a
2048 number of utility programs, and finally Exim itself. The command &`make
2049 makefile`& can be used to force a rebuild of the make file in the build
2050 directory, should this ever be necessary.
2052 If you have problems building Exim, check for any comments there may be in the
2053 &_README_& file concerning your operating system, and also take a look at the
2054 FAQ, where some common problems are covered.
2058 .section 'Output from &"make"&' "SECID283"
2059 The output produced by the &'make'& process for compile lines is often very
2060 unreadable, because these lines can be very long. For this reason, the normal
2061 output is suppressed by default, and instead output similar to that which
2062 appears when compiling the 2.6 Linux kernel is generated: just a short line for
2063 each module that is being compiled or linked. However, it is still possible to
2064 get the full output, by calling &'make'& like this:
2065 .code
2066 FULLECHO='' make -e
2067 .endd
2068 The value of FULLECHO defaults to &"@"&, the flag character that suppresses
2069 command reflection in &'make'&. When you ask for the full output, it is
2070 given in addition to the short output.
2074 .section "Overriding build-time options for Exim" "SECToverride"
2075 .cindex "build-time options, overriding"
2076 The main make file that is created at the beginning of the building process
2077 consists of the concatenation of a number of files which set configuration
2078 values, followed by a fixed set of &'make'& instructions. If a value is set
2079 more than once, the last setting overrides any previous ones. This provides a
2080 convenient way of overriding defaults. The files that are concatenated are, in
2081 order:
2082 .display
2083 &_OS/Makefile-Default_&
2084 &_OS/Makefile-_&<&'ostype'&>
2085 &_Local/Makefile_&
2086 &_Local/Makefile-_&<&'ostype'&>
2087 &_Local/Makefile-_&<&'archtype'&>
2088 &_Local/Makefile-_&<&'ostype'&>-<&'archtype'&>
2089 &_OS/Makefile-Base_&
2090 .endd
2091 .cindex "&_Local/Makefile_&"
2092 .cindex "building Exim" "operating system type"
2093 .cindex "building Exim" "architecture type"
2094 where <&'ostype'&> is the operating system type and <&'archtype'&> is the
2095 architecture type. &_Local/Makefile_& is required to exist, and the building
2096 process fails if it is absent. The other three &_Local_& files are optional,
2097 and are often not needed.
2099 The values used for <&'ostype'&> and <&'archtype'&> are obtained from scripts
2100 called &_scripts/os-type_& and &_scripts/arch-type_& respectively. If either of
2101 the environment variables EXIM_OSTYPE or EXIM_ARCHTYPE is set, their
2102 values are used, thereby providing a means of forcing particular settings.
2103 Otherwise, the scripts try to get values from the &%uname%& command. If this
2104 fails, the shell variables OSTYPE and ARCHTYPE are inspected. A number
2105 of &'ad hoc'& transformations are then applied, to produce the standard names
2106 that Exim expects. You can run these scripts directly from the shell in order
2107 to find out what values are being used on your system.
2110 &_OS/Makefile-Default_& contains comments about the variables that are set
2111 therein. Some (but not all) are mentioned below. If there is something that
2112 needs changing, review the contents of this file and the contents of the make
2113 file for your operating system (&_OS/Makefile-<ostype>_&) to see what the
2114 default values are.
2117 .cindex "building Exim" "overriding default settings"
2118 If you need to change any of the values that are set in &_OS/Makefile-Default_&
2119 or in &_OS/Makefile-<ostype>_&, or to add any new definitions, you do not
2120 need to change the original files. Instead, you should make the changes by
2121 putting the new values in an appropriate &_Local_& file. For example,
2122 .cindex "Tru64-Unix build-time settings"
2123 when building Exim in many releases of the Tru64-Unix (formerly Digital UNIX,
2124 formerly DEC-OSF1) operating system, it is necessary to specify that the C
2125 compiler is called &'cc'& rather than &'gcc'&. Also, the compiler must be
2126 called with the option &%-std1%&, to make it recognize some of the features of
2127 Standard C that Exim uses. (Most other compilers recognize Standard C by
2128 default.) To do this, you should create a file called &_Local/Makefile-OSF1_&
2129 containing the lines
2130 .code
2131 CC=cc
2132 CFLAGS=-std1
2133 .endd
2134 If you are compiling for just one operating system, it may be easier to put
2135 these lines directly into &_Local/Makefile_&.
2137 Keeping all your local configuration settings separate from the distributed
2138 files makes it easy to transfer them to new versions of Exim simply by copying
2139 the contents of the &_Local_& directory.
2142 .cindex "NIS lookup type" "including support for"
2143 .cindex "NIS+ lookup type" "including support for"
2144 .cindex "LDAP" "including support for"
2145 .cindex "lookup" "inclusion in binary"
2146 Exim contains support for doing LDAP, NIS, NIS+, and other kinds of file
2147 lookup, but not all systems have these components installed, so the default is
2148 not to include the relevant code in the binary. All the different kinds of file
2149 and database lookup that Exim supports are implemented as separate code modules
2150 which are included only if the relevant compile-time options are set. In the
2151 case of LDAP, NIS, and NIS+, the settings for &_Local/Makefile_& are:
2152 .code
2153 LOOKUP_LDAP=yes
2154 LOOKUP_NIS=yes
2156 .endd
2157 and similar settings apply to the other lookup types. They are all listed in
2158 &_src/EDITME_&. In many cases the relevant include files and interface
2159 libraries need to be installed before compiling Exim.
2160 .cindex "cdb" "including support for"
2161 However, there are some optional lookup types (such as cdb) for which
2162 the code is entirely contained within Exim, and no external include
2163 files or libraries are required. When a lookup type is not included in the
2164 binary, attempts to configure Exim to use it cause runtime configuration
2165 errors.
2167 .cindex "pkg-config" "lookups"
2168 .cindex "pkg-config" "authenticators"
2169 Many systems now use a tool called &'pkg-config'& to encapsulate information
2170 about how to compile against a library; Exim has some initial support for
2171 being able to use pkg-config for lookups and authenticators. For any given
2172 makefile variable which starts &`LOOKUP_`& or &`AUTH_`&, you can add a new
2173 variable with the &`_PC`& suffix in the name and assign as the value the
2174 name of the package to be queried. The results of querying via the
2175 &'pkg-config'& command will be added to the appropriate Makefile variables
2176 with &`+=`& directives, so your version of &'make'& will need to support that
2177 syntax. For instance:
2178 .code
2180 LOOKUP_SQLITE_PC=sqlite3
2181 AUTH_GSASL=yes
2182 AUTH_GSASL_PC=libgsasl
2184 AUTH_HEIMDAL_GSSAPI_PC=heimdal-gssapi
2185 .endd
2187 .cindex "Perl" "including support for"
2188 Exim can be linked with an embedded Perl interpreter, allowing Perl
2189 subroutines to be called during string expansion. To enable this facility,
2190 .code
2191 EXIM_PERL=perl.o
2192 .endd
2193 must be defined in &_Local/Makefile_&. Details of this facility are given in
2194 chapter &<<CHAPperl>>&.
2196 .cindex "X11 libraries, location of"
2197 The location of the X11 libraries is something that varies a lot between
2198 operating systems, and there may be different versions of X11 to cope
2199 with. Exim itself makes no use of X11, but if you are compiling the Exim
2200 monitor, the X11 libraries must be available.
2201 The following three variables are set in &_OS/Makefile-Default_&:
2202 .code
2203 X11=/usr/X11R6
2204 XINCLUDE=-I$(X11)/include
2205 XLFLAGS=-L$(X11)/lib
2206 .endd
2207 These are overridden in some of the operating-system configuration files. For
2208 example, in &_OS/Makefile-SunOS5_& there is
2209 .code
2210 X11=/usr/openwin
2211 XINCLUDE=-I$(X11)/include
2212 XLFLAGS=-L$(X11)/lib -R$(X11)/lib
2213 .endd
2214 If you need to override the default setting for your operating system, place a
2215 definition of all three of these variables into your
2216 &_Local/Makefile-<ostype>_& file.
2218 .cindex "EXTRALIBS"
2219 If you need to add any extra libraries to the link steps, these can be put in a
2220 variable called EXTRALIBS, which appears in all the link commands, but by
2221 default is not defined. In contrast, EXTRALIBS_EXIM is used only on the
2222 command for linking the main Exim binary, and not for any associated utilities.
2224 .cindex "DBM libraries" "configuration for building"
2225 There is also DBMLIB, which appears in the link commands for binaries that
2226 use DBM functions (see also section &<<SECTdb>>&). Finally, there is
2227 EXTRALIBS_EXIMON, which appears only in the link step for the Exim monitor
2228 binary, and which can be used, for example, to include additional X11
2229 libraries.
2231 .cindex "configuration file" "editing"
2232 The make file copes with rebuilding Exim correctly if any of the configuration
2233 files are edited. However, if an optional configuration file is deleted, it is
2234 necessary to touch the associated non-optional file (that is,
2235 &_Local/Makefile_& or &_Local/eximon.conf_&) before rebuilding.
2238 .section "OS-specific header files" "SECID30"
2239 .cindex "&_os.h_&"
2240 .cindex "building Exim" "OS-specific C header files"
2241 The &_OS_& directory contains a number of files with names of the form
2242 &_os.h-<ostype>_&. These are system-specific C header files that should not
2243 normally need to be changed. There is a list of macro settings that are
2244 recognized in the file &_OS/os.configuring_&, which should be consulted if you
2245 are porting Exim to a new operating system.
2249 .section "Overriding build-time options for the monitor" "SECID31"
2250 .cindex "building Eximon"
2251 A similar process is used for overriding things when building the Exim monitor,
2252 where the files that are involved are
2253 .display
2254 &_OS/eximon.conf-Default_&
2255 &_OS/eximon.conf-_&<&'ostype'&>
2256 &_Local/eximon.conf_&
2257 &_Local/eximon.conf-_&<&'ostype'&>
2258 &_Local/eximon.conf-_&<&'archtype'&>
2259 &_Local/eximon.conf-_&<&'ostype'&>-<&'archtype'&>
2260 .endd
2261 .cindex "&_Local/eximon.conf_&"
2262 As with Exim itself, the final three files need not exist, and in this case the
2263 &_OS/eximon.conf-<ostype>_& file is also optional. The default values in
2264 &_OS/eximon.conf-Default_& can be overridden dynamically by setting environment
2265 variables of the same name, preceded by EXIMON_. For example, setting
2266 EXIMON_LOG_DEPTH in the environment overrides the value of
2267 LOG_DEPTH at runtime.
2268 .ecindex IIDbuex
2271 .section "Installing Exim binaries and scripts" "SECID32"
2272 .cindex "installing Exim"
2273 .cindex "BIN_DIRECTORY"
2274 The command &`make install`& runs the &(exim_install)& script with no
2275 arguments. The script copies binaries and utility scripts into the directory
2276 whose name is specified by the BIN_DIRECTORY setting in &_Local/Makefile_&.
2277 .cindex "setuid" "installing Exim with"
2278 The install script copies files only if they are newer than the files they are
2279 going to replace. The Exim binary is required to be owned by root and have the
2280 &'setuid'& bit set, for normal configurations. Therefore, you must run &`make
2281 install`& as root so that it can set up the Exim binary in this way. However, in
2282 some special situations (for example, if a host is doing no local deliveries)
2283 it may be possible to run Exim without making the binary setuid root (see
2284 chapter &<<CHAPsecurity>>& for details).
2286 .cindex "CONFIGURE_FILE"
2287 Exim's runtime configuration file is named by the CONFIGURE_FILE setting
2288 in &_Local/Makefile_&. If this names a single file, and the file does not
2289 exist, the default configuration file &_src/configure.default_& is copied there
2290 by the installation script. If a runtime configuration file already exists, it
2291 is left alone. If CONFIGURE_FILE is a colon-separated list, naming several
2292 alternative files, no default is installed.
2294 .cindex "system aliases file"
2295 .cindex "&_/etc/aliases_&"
2296 One change is made to the default configuration file when it is installed: the
2297 default configuration contains a router that references a system aliases file.
2298 The path to this file is set to the value specified by
2299 SYSTEM_ALIASES_FILE in &_Local/Makefile_& (&_/etc/aliases_& by default).
2300 If the system aliases file does not exist, the installation script creates it,
2301 and outputs a comment to the user.
2303 The created file contains no aliases, but it does contain comments about the
2304 aliases a site should normally have. Mail aliases have traditionally been
2305 kept in &_/etc/aliases_&. However, some operating systems are now using
2306 &_/etc/mail/aliases_&. You should check if yours is one of these, and change
2307 Exim's configuration if necessary.
2309 The default configuration uses the local host's name as the only local domain,
2310 and is set up to do local deliveries into the shared directory &_/var/mail_&,
2311 running as the local user. System aliases and &_.forward_& files in users' home
2312 directories are supported, but no NIS or NIS+ support is configured. Domains
2313 other than the name of the local host are routed using the DNS, with delivery
2314 over SMTP.
2316 It is possible to install Exim for special purposes (such as building a binary
2317 distribution) in a private part of the file system. You can do this by a
2318 command such as
2319 .code
2320 make DESTDIR=/some/directory/ install
2321 .endd
2322 This has the effect of pre-pending the specified directory to all the file
2323 paths, except the name of the system aliases file that appears in the default
2324 configuration. (If a default alias file is created, its name &'is'& modified.)
2325 For backwards compatibility, ROOT is used if DESTDIR is not set,
2326 but this usage is deprecated.
2328 .cindex "installing Exim" "what is not installed"
2329 Running &'make install'& does not copy the Exim 4 conversion script
2330 &'convert4r4'&. You will probably run this only once if you are
2331 upgrading from Exim 3. None of the documentation files in the &_doc_&
2332 directory are copied, except for the info files when you have set
2333 INFO_DIRECTORY, as described in section &<<SECTinsinfdoc>>& below.
2335 For the utility programs, old versions are renamed by adding the suffix &_.O_&
2336 to their names. The Exim binary itself, however, is handled differently. It is
2337 installed under a name that includes the version number and the compile number,
2338 for example, &_exim-&version()-1_&. The script then arranges for a symbolic link
2339 called &_exim_& to point to the binary. If you are updating a previous version
2340 of Exim, the script takes care to ensure that the name &_exim_& is never absent
2341 from the directory (as seen by other processes).
2343 .cindex "installing Exim" "testing the script"
2344 If you want to see what the &'make install'& will do before running it for
2345 real, you can pass the &%-n%& option to the installation script by this
2346 command:
2347 .code
2348 make INSTALL_ARG=-n install
2349 .endd
2350 The contents of the variable INSTALL_ARG are passed to the installation
2351 script. You do not need to be root to run this test. Alternatively, you can run
2352 the installation script directly, but this must be from within the build
2353 directory. For example, from the top-level Exim directory you could use this
2354 command:
2355 .code
2356 (cd build-SunOS5-5.5.1-sparc; ../scripts/exim_install -n)
2357 .endd
2358 .cindex "installing Exim" "install script options"
2359 There are two other options that can be supplied to the installation script.
2361 .ilist
2362 &%-no_chown%& bypasses the call to change the owner of the installed binary
2363 to root, and the call to make it a setuid binary.
2364 .next
2365 &%-no_symlink%& bypasses the setting up of the symbolic link &_exim_& to the
2366 installed binary.
2367 .endlist
2369 INSTALL_ARG can be used to pass these options to the script. For example:
2370 .code
2371 make INSTALL_ARG=-no_symlink install
2372 .endd
2373 The installation script can also be given arguments specifying which files are
2374 to be copied. For example, to install just the Exim binary, and nothing else,
2375 without creating the symbolic link, you could use:
2376 .code
2377 make INSTALL_ARG='-no_symlink exim' install
2378 .endd
2382 .section "Installing info documentation" "SECTinsinfdoc"
2383 .cindex "installing Exim" "&'info'& documentation"
2384 Not all systems use the GNU &'info'& system for documentation, and for this
2385 reason, the Texinfo source of Exim's documentation is not included in the main
2386 distribution. Instead it is available separately from the FTP site (see section
2387 &<<SECTavail>>&).
2389 If you have defined INFO_DIRECTORY in &_Local/Makefile_& and the Texinfo
2390 source of the documentation is found in the source tree, running &`make
2391 install`& automatically builds the info files and installs them.
2395 .section "Setting up the spool directory" "SECID33"
2396 .cindex "spool directory" "creating"
2397 When it starts up, Exim tries to create its spool directory if it does not
2398 exist. The Exim uid and gid are used for the owner and group of the spool
2399 directory. Sub-directories are automatically created in the spool directory as
2400 necessary.
2405 .section "Testing" "SECID34"
2406 .cindex "testing" "installation"
2407 Having installed Exim, you can check that the runtime configuration file is
2408 syntactically valid by running the following command, which assumes that the
2409 Exim binary directory is within your PATH environment variable:
2410 .code
2411 exim -bV
2412 .endd
2413 If there are any errors in the configuration file, Exim outputs error messages.
2414 Otherwise it outputs the version number and build date,
2415 the DBM library that is being used, and information about which drivers and
2416 other optional code modules are included in the binary.
2417 Some simple routing tests can be done by using the address testing option. For
2418 example,
2419 .display
2420 &`exim -bt`& <&'local username'&>
2421 .endd
2422 should verify that it recognizes a local mailbox, and
2423 .display
2424 &`exim -bt`& <&'remote address'&>
2425 .endd
2426 a remote one. Then try getting it to deliver mail, both locally and remotely.
2427 This can be done by passing messages directly to Exim, without going through a
2428 user agent. For example:
2429 .code
2430 exim -v postmaster@your.domain.example
2431 From: user@your.domain.example
2432 To: postmaster@your.domain.example
2433 Subject: Testing Exim
2435 This is a test message.
2436 ^D
2437 .endd
2438 The &%-v%& option causes Exim to output some verification of what it is doing.
2439 In this case you should see copies of three log lines, one for the message's
2440 arrival, one for its delivery, and one containing &"Completed"&.
2442 .cindex "delivery" "problems with"
2443 If you encounter problems, look at Exim's log files (&'mainlog'& and
2444 &'paniclog'&) to see if there is any relevant information there. Another source
2445 of information is running Exim with debugging turned on, by specifying the
2446 &%-d%& option. If a message is stuck on Exim's spool, you can force a delivery
2447 with debugging turned on by a command of the form
2448 .display
2449 &`exim -d -M`& <&'exim-message-id'&>
2450 .endd
2451 You must be root or an &"admin user"& in order to do this. The &%-d%& option
2452 produces rather a lot of output, but you can cut this down to specific areas.
2453 For example, if you use &%-d-all+route%& only the debugging information
2454 relevant to routing is included. (See the &%-d%& option in chapter
2455 &<<CHAPcommandline>>& for more details.)
2457 .cindex '&"sticky"& bit'
2458 .cindex "lock files"
2459 One specific problem that has shown up on some sites is the inability to do
2460 local deliveries into a shared mailbox directory, because it does not have the
2461 &"sticky bit"& set on it. By default, Exim tries to create a lock file before
2462 writing to a mailbox file, and if it cannot create the lock file, the delivery
2463 is deferred. You can get round this either by setting the &"sticky bit"& on the
2464 directory, or by setting a specific group for local deliveries and allowing
2465 that group to create files in the directory (see the comments above the
2466 &(local_delivery)& transport in the default configuration file). Another
2467 approach is to configure Exim not to use lock files, but just to rely on
2468 &[fcntl()]& locking instead. However, you should do this only if all user
2469 agents also use &[fcntl()]& locking. For further discussion of locking issues,
2470 see chapter &<<CHAPappendfile>>&.
2472 One thing that cannot be tested on a system that is already running an MTA is
2473 the receipt of incoming SMTP mail on the standard SMTP port. However, the
2474 &%-oX%& option can be used to run an Exim daemon that listens on some other
2475 port, or &'inetd'& can be used to do this. The &%-bh%& option and the
2476 &'exim_checkaccess'& utility can be used to check out policy controls on
2477 incoming SMTP mail.
2479 Testing a new version on a system that is already running Exim can most easily
2480 be done by building a binary with a different CONFIGURE_FILE setting. From
2481 within the runtime configuration, all other file and directory names
2482 that Exim uses can be altered, in order to keep it entirely clear of the
2483 production version.
2486 .section "Replacing another MTA with Exim" "SECID35"
2487 .cindex "replacing another MTA"
2488 Building and installing Exim for the first time does not of itself put it in
2489 general use. The name by which the system's MTA is called by mail user agents
2490 is either &_/usr/sbin/sendmail_&, or &_/usr/lib/sendmail_& (depending on the
2491 operating system), and it is necessary to make this name point to the &'exim'&
2492 binary in order to get the user agents to pass messages to Exim. This is
2493 normally done by renaming any existing file and making &_/usr/sbin/sendmail_&
2494 or &_/usr/lib/sendmail_&
2495 .cindex "symbolic link" "to &'exim'& binary"
2496 a symbolic link to the &'exim'& binary. It is a good idea to remove any setuid
2497 privilege and executable status from the old MTA. It is then necessary to stop
2498 and restart the mailer daemon, if one is running.
2500 .cindex "FreeBSD, MTA indirection"
2501 .cindex "&_/etc/mail/mailer.conf_&"
2502 Some operating systems have introduced alternative ways of switching MTAs. For
2503 example, if you are running FreeBSD, you need to edit the file
2504 &_/etc/mail/mailer.conf_& instead of setting up a symbolic link as just
2505 described. A typical example of the contents of this file for running Exim is
2506 as follows:
2507 .code
2508 sendmail /usr/exim/bin/exim
2509 send-mail /usr/exim/bin/exim
2510 mailq /usr/exim/bin/exim -bp
2511 newaliases /usr/bin/true
2512 .endd
2513 Once you have set up the symbolic link, or edited &_/etc/mail/mailer.conf_&,
2514 your Exim installation is &"live"&. Check it by sending a message from your
2515 favourite user agent.
2517 You should consider what to tell your users about the change of MTA. Exim may
2518 have different capabilities to what was previously running, and there are
2519 various operational differences such as the text of messages produced by
2520 command line options and in bounce messages. If you allow your users to make
2521 use of Exim's filtering capabilities, you should make the document entitled
2522 &'Exim's interface to mail filtering'& available to them.
2526 .section "Upgrading Exim" "SECID36"
2527 .cindex "upgrading Exim"
2528 If you are already running Exim on your host, building and installing a new
2529 version automatically makes it available to MUAs, or any other programs that
2530 call the MTA directly. However, if you are running an Exim daemon, you do need
2531 .cindex restart "on HUP signal"
2532 .cindex signal "HUP, to restart"
2533 to send it a HUP signal, to make it re-execute itself, and thereby pick up the
2534 new binary. You do not need to stop processing mail in order to install a new
2535 version of Exim. The install script does not modify an existing runtime
2536 configuration file.
2541 .section "Stopping the Exim daemon on Solaris" "SECID37"
2542 .cindex "Solaris" "stopping Exim on"
2543 The standard command for stopping the mailer daemon on Solaris is
2544 .code
2545 /etc/init.d/sendmail stop
2546 .endd
2547 If &_/usr/lib/sendmail_& has been turned into a symbolic link, this script
2548 fails to stop Exim because it uses the command &'ps -e'& and greps the output
2549 for the text &"sendmail"&; this is not present because the actual program name
2550 (that is, &"exim"&) is given by the &'ps'& command with these options. A
2551 solution is to replace the line that finds the process id with something like
2552 .code
2553 pid=`cat /var/spool/exim/exim-daemon.pid`
2554 .endd
2555 to obtain the daemon's pid directly from the file that Exim saves it in.
2557 Note, however, that stopping the daemon does not &"stop Exim"&. Messages can
2558 still be received from local processes, and if automatic delivery is configured
2559 (the normal case), deliveries will still occur.
2564 . ////////////////////////////////////////////////////////////////////////////
2565 . ////////////////////////////////////////////////////////////////////////////
2567 .chapter "The Exim command line" "CHAPcommandline"
2568 .scindex IIDclo1 "command line" "options"
2569 .scindex IIDclo2 "options" "command line"
2570 Exim's command line takes the standard Unix form of a sequence of options,
2571 each starting with a hyphen character, followed by a number of arguments. The
2572 options are compatible with the main options of Sendmail, and there are also
2573 some additional options, some of which are compatible with Smail 3. Certain
2574 combinations of options do not make sense, and provoke an error if used.
2575 The form of the arguments depends on which options are set.
2578 .section "Setting options by program name" "SECID38"
2579 .cindex "&'mailq'&"
2580 If Exim is called under the name &'mailq'&, it behaves as if the option &%-bp%&
2581 were present before any other options.
2582 The &%-bp%& option requests a listing of the contents of the mail queue on the
2583 standard output.
2584 This feature is for compatibility with some systems that contain a command of
2585 that name in one of the standard libraries, symbolically linked to
2586 &_/usr/sbin/sendmail_& or &_/usr/lib/sendmail_&.
2588 .cindex "&'rsmtp'&"
2589 If Exim is called under the name &'rsmtp'& it behaves as if the option &%-bS%&
2590 were present before any other options, for compatibility with Smail. The
2591 &%-bS%& option is used for reading in a number of messages in batched SMTP
2592 format.
2594 .cindex "&'rmail'&"
2595 If Exim is called under the name &'rmail'& it behaves as if the &%-i%& and
2596 &%-oee%& options were present before any other options, for compatibility with
2597 Smail. The name &'rmail'& is used as an interface by some UUCP systems.
2599 .cindex "&'runq'&"
2600 .cindex "queue runner"
2601 If Exim is called under the name &'runq'& it behaves as if the option &%-q%&
2602 were present before any other options, for compatibility with Smail. The &%-q%&
2603 option causes a single queue runner process to be started.
2605 .cindex "&'newaliases'&"
2606 .cindex "alias file" "building"
2607 .cindex "Sendmail compatibility" "calling Exim as &'newaliases'&"
2608 If Exim is called under the name &'newaliases'& it behaves as if the option
2609 &%-bi%& were present before any other options, for compatibility with Sendmail.
2610 This option is used for rebuilding Sendmail's alias file. Exim does not have
2611 the concept of a single alias file, but can be configured to run a given
2612 command if called with the &%-bi%& option.
2615 .section "Trusted and admin users" "SECTtrustedadmin"
2616 Some Exim options are available only to &'trusted users'& and others are
2617 available only to &'admin users'&. In the description below, the phrases &"Exim
2618 user"& and &"Exim group"& mean the user and group defined by EXIM_USER and
2619 EXIM_GROUP in &_Local/Makefile_& or set by the &%exim_user%& and
2620 &%exim_group%& options. These do not necessarily have to use the name &"exim"&.
2622 .ilist
2623 .cindex "trusted users" "definition of"
2624 .cindex "user" "trusted definition of"
2625 The trusted users are root, the Exim user, any user listed in the
2626 &%trusted_users%& configuration option, and any user whose current group or any
2627 supplementary group is one of those listed in the &%trusted_groups%&
2628 configuration option. Note that the Exim group is not automatically trusted.
2630 .cindex '&"From"& line'
2631 .cindex "envelope from"
2632 .cindex "envelope sender"
2633 Trusted users are always permitted to use the &%-f%& option or a leading
2634 &"From&~"& line to specify the envelope sender of a message that is passed to
2635 Exim through the local interface (see the &%-bm%& and &%-f%& options below).
2636 See the &%untrusted_set_sender%& option for a way of permitting non-trusted
2637 users to set envelope senders.
2639 .cindex "&'From:'& header line"
2640 .cindex "&'Sender:'& header line"
2641 .cindex "header lines" "From:"
2642 .cindex "header lines" "Sender:"
2643 For a trusted user, there is never any check on the contents of the &'From:'&
2644 header line, and a &'Sender:'& line is never added. Furthermore, any existing
2645 &'Sender:'& line in incoming local (non-TCP/IP) messages is not removed.
2647 Trusted users may also specify a host name, host address, interface address,
2648 protocol name, ident value, and authentication data when submitting a message
2649 locally. Thus, they are able to insert messages into Exim's queue locally that
2650 have the characteristics of messages received from a remote host. Untrusted
2651 users may in some circumstances use &%-f%&, but can never set the other values
2652 that are available to trusted users.
2653 .next
2654 .cindex "user" "admin definition of"
2655 .cindex "admin user" "definition of"
2656 The admin users are root, the Exim user, and any user that is a member of the
2657 Exim group or of any group listed in the &%admin_groups%& configuration option.
2658 The current group does not have to be one of these groups.
2660 Admin users are permitted to list the queue, and to carry out certain
2661 operations on messages, for example, to force delivery failures. It is also
2662 necessary to be an admin user in order to see the full information provided by
2663 the Exim monitor, and full debugging output.
2665 By default, the use of the &%-M%&, &%-q%&, &%-R%&, and &%-S%& options to cause
2666 Exim to attempt delivery of messages on its queue is restricted to admin users.
2667 However, this restriction can be relaxed by setting the &%prod_requires_admin%&
2668 option false (that is, specifying &%no_prod_requires_admin%&).
2670 Similarly, the use of the &%-bp%& option to list all the messages in the queue
2671 is restricted to admin users unless &%queue_list_requires_admin%& is set
2672 false.
2673 .endlist
2676 &*Warning*&: If you configure your system so that admin users are able to
2677 edit Exim's configuration file, you are giving those users an easy way of
2678 getting root. There is further discussion of this issue at the start of chapter
2679 &<<CHAPconf>>&.
2684 .section "Command line options" "SECID39"
2685 Exim's command line options are described in alphabetical order below. If none
2686 of the options that specifies a specific action (such as starting the daemon or
2687 a queue runner, or testing an address, or receiving a message in a specific
2688 format, or listing the queue) are present, and there is at least one argument
2689 on the command line, &%-bm%& (accept a local message on the standard input,
2690 with the arguments specifying the recipients) is assumed. Otherwise, Exim
2691 outputs a brief message about itself and exits.
2693 . ////////////////////////////////////////////////////////////////////////////
2694 . Insert a stylized XML comment here, to identify the start of the command line
2695 . options. This is for the benefit of the Perl script that automatically
2696 . creates a man page for the options.
2697 . ////////////////////////////////////////////////////////////////////////////
2699 .literal xml
2700 <!-- === Start of command line options === -->
2701 .literal off
2704 .vlist
2705 .vitem &%--%&
2706 .oindex "--"
2707 .cindex "options" "command line; terminating"
2708 This is a pseudo-option whose only purpose is to terminate the options and
2709 therefore to cause subsequent command line items to be treated as arguments
2710 rather than options, even if they begin with hyphens.
2712 .vitem &%--help%&
2713 .oindex "&%--help%&"
2714 This option causes Exim to output a few sentences stating what it is.
2715 The same output is generated if the Exim binary is called with no options and
2716 no arguments.
2718 .vitem &%--version%&
2719 .oindex "&%--version%&"
2720 This option is an alias for &%-bV%& and causes version information to be
2721 displayed.
2723 .vitem &%-Ac%& &&&
2724 &%-Am%&
2725 .oindex "&%-Ac%&"
2726 .oindex "&%-Am%&"
2727 These options are used by Sendmail for selecting configuration files and are
2728 ignored by Exim.
2730 .vitem &%-B%&<&'type'&>
2731 .oindex "&%-B%&"
2732 .cindex "8-bit characters"
2733 .cindex "Sendmail compatibility" "8-bit characters"
2734 This is a Sendmail option for selecting 7 or 8 bit processing. Exim is 8-bit
2735 clean; it ignores this option.
2737 .vitem &%-bd%&
2738 .oindex "&%-bd%&"
2739 .cindex "daemon"
2740 .cindex "SMTP" "listener"
2741 .cindex "queue runner"
2742 This option runs Exim as a daemon, awaiting incoming SMTP connections. Usually
2743 the &%-bd%& option is combined with the &%-q%&<&'time'&> option, to specify
2744 that the daemon should also initiate periodic queue runs.
2746 The &%-bd%& option can be used only by an admin user. If either of the &%-d%&
2747 (debugging) or &%-v%& (verifying) options are set, the daemon does not
2748 disconnect from the controlling terminal. When running this way, it can be
2749 stopped by pressing ctrl-C.
2751 By default, Exim listens for incoming connections to the standard SMTP port on
2752 all the host's running interfaces. However, it is possible to listen on other
2753 ports, on multiple ports, and only on specific interfaces. Chapter
2754 &<<CHAPinterfaces>>& contains a description of the options that control this.
2756 When a listening daemon
2757 .cindex "daemon" "process id (pid)"
2758 .cindex "pid (process id)" "of daemon"
2759 is started without the use of &%-oX%& (that is, without overriding the normal
2760 configuration), it writes its process id to a file called &_exim-daemon.pid_&
2761 in Exim's spool directory. This location can be overridden by setting
2762 PID_FILE_PATH in &_Local/Makefile_&. The file is written while Exim is still
2763 running as root.
2765 When &%-oX%& is used on the command line to start a listening daemon, the
2766 process id is not written to the normal pid file path. However, &%-oP%& can be
2767 used to specify a path on the command line if a pid file is required.
2769 The SIGHUP signal
2770 .cindex "SIGHUP"
2771 .cindex restart "on HUP signal"
2772 .cindex signal "HUP, to restart"
2773 .cindex "daemon" "restarting"
2774 .cindex signal "to reload configuration"
2775 .cindex daemon "reload configuration"
2776 .cindex reload configuration
2777 can be used to cause the daemon to re-execute itself. This should be done
2778 whenever Exim's configuration file, or any file that is incorporated into it by
2779 means of the &%.include%& facility, is changed, and also whenever a new version
2780 of Exim is installed. It is not necessary to do this when other files that are
2781 referenced from the configuration (for example, alias files) are changed,
2782 because these are reread each time they are used.
2784 .vitem &%-bdf%&
2785 .oindex "&%-bdf%&"
2786 This option has the same effect as &%-bd%& except that it never disconnects
2787 from the controlling terminal, even when no debugging is specified.
2789 .vitem &%-be%&
2790 .oindex "&%-be%&"
2791 .cindex "testing" "string expansion"
2792 .cindex "expansion" "testing"
2793 Run Exim in expansion testing mode. Exim discards its root privilege, to
2794 prevent ordinary users from using this mode to read otherwise inaccessible
2795 files. If no arguments are given, Exim runs interactively, prompting for lines
2796 of data. Otherwise, it processes each argument in turn.
2798 If Exim was built with USE_READLINE=yes in &_Local/Makefile_&, it tries
2799 to load the &%libreadline%& library dynamically whenever the &%-be%& option is
2800 used without command line arguments. If successful, it uses the &[readline()]&
2801 function, which provides extensive line-editing facilities, for reading the
2802 test data. A line history is supported.
2804 Long expansion expressions can be split over several lines by using backslash
2805 continuations. As in Exim's runtime configuration, white space at the start of
2806 continuation lines is ignored. Each argument or data line is passed through the
2807 string expansion mechanism, and the result is output. Variable values from the
2808 configuration file (for example, &$qualify_domain$&) are available, but no
2809 message-specific values (such as &$message_exim_id$&) are set, because no message
2810 is being processed (but see &%-bem%& and &%-Mset%&).
2812 &*Note*&: If you use this mechanism to test lookups, and you change the data
2813 files or databases you are using, you must exit and restart Exim before trying
2814 the same lookup again. Otherwise, because each Exim process caches the results
2815 of lookups, you will just get the same result as before.
2817 Macro processing is done on lines before string-expansion: new macros can be
2818 defined and macros will be expanded.
2819 Because macros in the config file are often used for secrets, those are only
2820 available to admin users.
2822 .vitem &%-bem%&&~<&'filename'&>
2823 .oindex "&%-bem%&"
2824 .cindex "testing" "string expansion"
2825 .cindex "expansion" "testing"
2826 This option operates like &%-be%& except that it must be followed by the name
2827 of a file. For example:
2828 .code
2829 exim -bem /tmp/testmessage
2830 .endd
2831 The file is read as a message (as if receiving a locally-submitted non-SMTP
2832 message) before any of the test expansions are done. Thus, message-specific
2833 variables such as &$message_size$& and &$header_from:$& are available. However,
2834 no &'Received:'& header is added to the message. If the &%-t%& option is set,
2835 recipients are read from the headers in the normal way, and are shown in the
2836 &$recipients$& variable. Note that recipients cannot be given on the command
2837 line, because further arguments are taken as strings to expand (just like
2838 &%-be%&).
2840 .vitem &%-bF%&&~<&'filename'&>
2841 .oindex "&%-bF%&"
2842 .cindex "system filter" "testing"
2843 .cindex "testing" "system filter"
2844 This option is the same as &%-bf%& except that it assumes that the filter being
2845 tested is a system filter. The additional commands that are available only in
2846 system filters are recognized.
2848 .vitem &%-bf%&&~<&'filename'&>
2849 .oindex "&%-bf%&"
2850 .cindex "filter" "testing"
2851 .cindex "testing" "filter file"
2852 .cindex "forward file" "testing"
2853 .cindex "testing" "forward file"
2854 .cindex "Sieve filter" "testing"
2855 This option runs Exim in user filter testing mode; the file is the filter file
2856 to be tested, and a test message must be supplied on the standard input. If
2857 there are no message-dependent tests in the filter, an empty file can be
2858 supplied.
2860 If you want to test a system filter file, use &%-bF%& instead of &%-bf%&. You
2861 can use both &%-bF%& and &%-bf%& on the same command, in order to test a system
2862 filter and a user filter in the same run. For example:
2863 .code
2864 exim -bF /system/filter -bf /user/filter </test/message
2865 .endd
2866 This is helpful when the system filter adds header lines or sets filter
2867 variables that are used by the user filter.
2869 If the test filter file does not begin with one of the special lines
2870 .code
2871 # Exim filter
2872 # Sieve filter
2873 .endd
2874 it is taken to be a normal &_.forward_& file, and is tested for validity under
2875 that interpretation. See sections &<<SECTitenonfilred>>& to
2876 &<<SECTspecitredli>>& for a description of the possible contents of non-filter
2877 redirection lists.
2879 The result of an Exim command that uses &%-bf%&, provided no errors are
2880 detected, is a list of the actions that Exim would try to take if presented
2881 with the message for real. More details of filter testing are given in the
2882 separate document entitled &'Exim's interfaces to mail filtering'&.
2884 When testing a filter file,
2885 .cindex "&""From""& line"
2886 .cindex "envelope from"
2887 .cindex "envelope sender"
2888 .oindex "&%-f%&" "for filter testing"
2889 the envelope sender can be set by the &%-f%& option,
2890 or by a &"From&~"& line at the start of the test message. Various parameters
2891 that would normally be taken from the envelope recipient address of the message
2892 can be set by means of additional command line options (see the next four
2893 options).
2895 .vitem &%-bfd%&&~<&'domain'&>
2896 .oindex "&%-bfd%&"
2897 .vindex "&$qualify_domain$&"
2898 This sets the domain of the recipient address when a filter file is being
2899 tested by means of the &%-bf%& option. The default is the value of
2900 &$qualify_domain$&.
2902 .vitem &%-bfl%&&~<&'local&~part'&>
2903 .oindex "&%-bfl%&"
2904 This sets the local part of the recipient address when a filter file is being
2905 tested by means of the &%-bf%& option. The default is the username of the
2906 process that calls Exim. A local part should be specified with any prefix or
2907 suffix stripped, because that is how it appears to the filter when a message is
2908 actually being delivered.
2910 .vitem &%-bfp%&&~<&'prefix'&>
2911 .oindex "&%-bfp%&"
2912 .cindex affix "filter testing"
2913 This sets the prefix of the local part of the recipient address when a filter
2914 file is being tested by means of the &%-bf%& option. The default is an empty
2915 prefix.
2917 .vitem &%-bfs%&&~<&'suffix'&>
2918 .oindex "&%-bfs%&"
2919 .cindex affix "filter testing"
2920 This sets the suffix of the local part of the recipient address when a filter
2921 file is being tested by means of the &%-bf%& option. The default is an empty
2922 suffix.
2924 .vitem &%-bh%&&~<&'IP&~address'&>
2925 .oindex "&%-bh%&"
2926 .cindex "testing" "incoming SMTP"
2927 .cindex "SMTP" "testing incoming"
2928 .cindex "testing" "relay control"
2929 .cindex "relaying" "testing configuration"
2930 .cindex "policy control" "testing"
2931 .cindex "debugging" "&%-bh%& option"
2932 This option runs a fake SMTP session as if from the given IP address, using the
2933 standard input and output. The IP address may include a port number at the end,
2934 after a full stop. For example:
2935 .code
2936 exim -bh
2937 exim -bh fe80::a00:20ff:fe86:a061.5678
2938 .endd
2939 When an IPv6 address is given, it is converted into canonical form. In the case
2940 of the second example above, the value of &$sender_host_address$& after
2941 conversion to the canonical form is
2942 &`fe80:0000:0000:0a00:20ff:fe86:a061.5678`&.
2944 Comments as to what is going on are written to the standard error file. These
2945 include lines beginning with &"LOG"& for anything that would have been logged.
2946 This facility is provided for testing configuration options for incoming
2947 messages, to make sure they implement the required policy. For example, you can
2948 test your relay controls using &%-bh%&.
2950 &*Warning 1*&:
2951 .cindex "RFC 1413"
2952 You can test features of the configuration that rely on ident (RFC 1413)
2953 information by using the &%-oMt%& option. However, Exim cannot actually perform
2954 an ident callout when testing using &%-bh%& because there is no incoming SMTP
2955 connection.
2957 &*Warning 2*&: Address verification callouts (see section &<<SECTcallver>>&)
2958 are also skipped when testing using &%-bh%&. If you want these callouts to
2959 occur, use &%-bhc%& instead.
2961 Messages supplied during the testing session are discarded, and nothing is
2962 written to any of the real log files. There may be pauses when DNS (and other)
2963 lookups are taking place, and of course these may time out. The &%-oMi%& option
2964 can be used to specify a specific IP interface and port if this is important,
2965 and &%-oMaa%& and &%-oMai%& can be used to set parameters as if the SMTP
2966 session were authenticated.
2968 The &'exim_checkaccess'& utility is a &"packaged"& version of &%-bh%& whose
2969 output just states whether a given recipient address from a given host is
2970 acceptable or not. See section &<<SECTcheckaccess>>&.
2972 Features such as authentication and encryption, where the client input is not
2973 plain text, cannot easily be tested with &%-bh%&. Instead, you should use a
2974 specialized SMTP test program such as
2975 &url(https://www.jetmore.org/john/code/swaks/,swaks).
2977 .vitem &%-bhc%&&~<&'IP&~address'&>
2978 .oindex "&%-bhc%&"
2979 This option operates in the same way as &%-bh%&, except that address
2980 verification callouts are performed if required. This includes consulting and
2981 updating the callout cache database.
2983 .vitem &%-bi%&
2984 .oindex "&%-bi%&"
2985 .cindex "alias file" "building"
2986 .cindex "building alias file"
2987 .cindex "Sendmail compatibility" "&%-bi%& option"
2988 Sendmail interprets the &%-bi%& option as a request to rebuild its alias file.
2989 Exim does not have the concept of a single alias file, and so it cannot mimic
2990 this behaviour. However, calls to &_/usr/lib/sendmail_& with the &%-bi%& option
2991 tend to appear in various scripts such as NIS make files, so the option must be
2992 recognized.
2994 If &%-bi%& is encountered, the command specified by the &%bi_command%&
2995 configuration option is run, under the uid and gid of the caller of Exim. If
2996 the &%-oA%& option is used, its value is passed to the command as an argument.
2997 The command set by &%bi_command%& may not contain arguments. The command can
2998 use the &'exim_dbmbuild'& utility, or some other means, to rebuild alias files
2999 if this is required. If the &%bi_command%& option is not set, calling Exim with
3000 &%-bi%& is a no-op.
3002 . // Keep :help first, then the rest in alphabetical order
3003 .vitem &%-bI:help%&
3004 .oindex "&%-bI:help%&"
3005 .cindex "querying exim information"
3006 We shall provide various options starting &`-bI:`& for querying Exim for
3007 information. The output of many of these will be intended for machine
3008 consumption. This one is not. The &%-bI:help%& option asks Exim for a
3009 synopsis of supported options beginning &`-bI:`&. Use of any of these
3010 options shall cause Exim to exit after producing the requested output.
3012 .vitem &%-bI:dscp%&
3013 .oindex "&%-bI:dscp%&"
3014 .cindex "DSCP" "values"
3015 This option causes Exim to emit an alphabetically sorted list of all
3016 recognised DSCP names.
3018 .vitem &%-bI:sieve%&
3019 .oindex "&%-bI:sieve%&"
3020 .cindex "Sieve filter" "capabilities"
3021 This option causes Exim to emit an alphabetically sorted list of all supported
3022 Sieve protocol extensions on stdout, one per line. This is anticipated to be
3023 useful for ManageSieve (RFC 5804) implementations, in providing that protocol's
3024 &`SIEVE`& capability response line. As the precise list may depend upon
3025 compile-time build options, which this option will adapt to, this is the only
3026 way to guarantee a correct response.
3028 .vitem &%-bm%&
3029 .oindex "&%-bm%&"
3030 .cindex "local message reception"
3031 This option runs an Exim receiving process that accepts an incoming,
3032 locally-generated message on the standard input. The recipients are given as the
3033 command arguments (except when &%-t%& is also present &-- see below). Each
3034 argument can be a comma-separated list of RFC 2822 addresses. This is the
3035 default option for selecting the overall action of an Exim call; it is assumed
3036 if no other conflicting option is present.
3038 If any addresses in the message are unqualified (have no domain), they are
3039 qualified by the values of the &%qualify_domain%& or &%qualify_recipient%&
3040 options, as appropriate. The &%-bnq%& option (see below) provides a way of
3041 suppressing this for special cases.
3043 Policy checks on the contents of local messages can be enforced by means of
3044 the non-SMTP ACL. See chapter &<<CHAPACL>>& for details.
3046 .cindex "return code" "for &%-bm%&"
3047 The return code is zero if the message is successfully accepted. Otherwise, the
3048 action is controlled by the &%-oe%&&'x'& option setting &-- see below.
3050 The format
3051 .cindex "message" "format"
3052 .cindex "format" "message"
3053 .cindex "&""From""& line"
3054 .cindex "UUCP" "&""From""& line"
3055 .cindex "Sendmail compatibility" "&""From""& line"
3056 of the message must be as defined in RFC 2822, except that, for
3057 compatibility with Sendmail and Smail, a line in one of the forms
3058 .code
3059 From sender Fri Jan 5 12:55 GMT 1997
3060 From sender Fri, 5 Jan 97 12:55:01
3061 .endd
3062 (with the weekday optional, and possibly with additional text after the date)
3063 is permitted to appear at the start of the message. There appears to be no
3064 authoritative specification of the format of this line. Exim recognizes it by
3065 matching against the regular expression defined by the &%uucp_from_pattern%&
3066 option, which can be changed if necessary.
3068 .oindex "&%-f%&" "overriding &""From""& line"
3069 The specified sender is treated as if it were given as the argument to the
3070 &%-f%& option, but if a &%-f%& option is also present, its argument is used in
3071 preference to the address taken from the message. The caller of Exim must be a
3072 trusted user for the sender of a message to be set in this way.
3074 .vitem &%-bmalware%&&~<&'filename'&>
3075 .oindex "&%-bmalware%&"
3076 .cindex "testing", "malware"
3077 .cindex "malware scan test"
3078 This debugging option causes Exim to scan the given file or directory
3079 (depending on the used scanner interface),
3080 using the malware scanning framework. The option of &%av_scanner%& influences
3081 this option, so if &%av_scanner%&'s value is dependent upon an expansion then
3082 the expansion should have defaults which apply to this invocation. ACLs are
3083 not invoked, so if &%av_scanner%& references an ACL variable then that variable
3084 will never be populated and &%-bmalware%& will fail.
3086 Exim will have changed working directory before resolving the filename, so
3087 using fully qualified pathnames is advisable. Exim will be running as the Exim
3088 user when it tries to open the file, rather than as the invoking user.
3089 This option requires admin privileges.
3091 The &%-bmalware%& option will not be extended to be more generally useful,
3092 there are better tools for file-scanning. This option exists to help
3093 administrators verify their Exim and AV scanner configuration.
3095 .vitem &%-bnq%&
3096 .oindex "&%-bnq%&"
3097 .cindex "address qualification, suppressing"
3098 By default, Exim automatically qualifies unqualified addresses (those
3099 without domains) that appear in messages that are submitted locally (that
3100 is, not over TCP/IP). This qualification applies both to addresses in
3101 envelopes, and addresses in header lines. Sender addresses are qualified using
3102 &%qualify_domain%&, and recipient addresses using &%qualify_recipient%& (which
3103 defaults to the value of &%qualify_domain%&).
3105 Sometimes, qualification is not wanted. For example, if &%-bS%& (batch SMTP) is
3106 being used to re-submit messages that originally came from remote hosts after
3107 content scanning, you probably do not want to qualify unqualified addresses in
3108 header lines. (Such lines will be present only if you have not enabled a header
3109 syntax check in the appropriate ACL.)
3111 The &%-bnq%& option suppresses all qualification of unqualified addresses in
3112 messages that originate on the local host. When this is used, unqualified
3113 addresses in the envelope provoke errors (causing message rejection) and
3114 unqualified addresses in header lines are left alone.
3117 .vitem &%-bP%&
3118 .oindex "&%-bP%&"
3119 .cindex "configuration options" "extracting"
3120 .cindex "options" "configuration &-- extracting"
3121 If this option is given with no arguments, it causes the values of all Exim's
3122 main configuration options to be written to the standard output. The values
3123 of one or more specific options can be requested by giving their names as
3124 arguments, for example:
3125 .code
3126 exim -bP qualify_domain hold_domains
3127 .endd
3128 .cindex "hiding configuration option values"
3129 .cindex "configuration options" "hiding value of"
3130 .cindex "options" "hiding value of"
3131 However, any option setting that is preceded by the word &"hide"& in the
3132 configuration file is not shown in full, except to an admin user. For other
3133 users, the output is as in this example:
3134 .code
3135 mysql_servers = <value not displayable>
3136 .endd
3137 If &%config%& is given as an argument, the config is
3138 output, as it was parsed, any include file resolved, any comment removed.
3140 If &%config_file%& is given as an argument, the name of the runtime
3141 configuration file is output. (&%configure_file%& works too, for
3142 backward compatibility.)
3143 If a list of configuration files was supplied, the value that is output here
3144 is the name of the file that was actually used.
3146 .cindex "options" "hiding name of"
3147 If the &%-n%& flag is given, then for most modes of &%-bP%& operation the
3148 name will not be output.
3150 .cindex "daemon" "process id (pid)"
3151 .cindex "pid (process id)" "of daemon"
3152 If &%log_file_path%& or &%pid_file_path%& are given, the names of the
3153 directories where log files and daemon pid files are written are output,
3154 respectively. If these values are unset, log files are written in a
3155 sub-directory of the spool directory called &%log%&, and the pid file is
3156 written directly into the spool directory.
3158 If &%-bP%& is followed by a name preceded by &`+`&, for example,
3159 .code
3160 exim -bP +local_domains
3161 .endd
3162 it searches for a matching named list of any type (domain, host, address, or
3163 local part) and outputs what it finds.
3165 .cindex "options" "router &-- extracting"
3166 .cindex "options" "transport &-- extracting"
3167 .cindex "options" "authenticator &-- extracting"
3168 If one of the words &%router%&, &%transport%&, or &%authenticator%& is given,
3169 followed by the name of an appropriate driver instance, the option settings for
3170 that driver are output. For example:
3171 .code
3172 exim -bP transport local_delivery
3173 .endd
3174 The generic driver options are output first, followed by the driver's private
3175 options. A list of the names of drivers of a particular type can be obtained by
3176 using one of the words &%router_list%&, &%transport_list%&, or
3177 &%authenticator_list%&, and a complete list of all drivers with their option
3178 settings can be obtained by using &%routers%&, &%transports%&, or
3179 &%authenticators%&.
3181 .cindex "environment"
3182 If &%environment%& is given as an argument, the set of environment
3183 variables is output, line by line. Using the &%-n%& flag suppresses the value of the
3184 variables.
3186 .cindex "options" "macro &-- extracting"
3187 If invoked by an admin user, then &%macro%&, &%macro_list%& and &%macros%&
3188 are available, similarly to the drivers. Because macros are sometimes used
3189 for storing passwords, this option is restricted.
3190 The output format is one item per line.
3191 For the "-bP macro <name>" form, if no such macro is found
3192 the exit status will be nonzero.
3194 .vitem &%-bp%&
3195 .oindex "&%-bp%&"
3196 .cindex "queue" "listing messages in"
3197 .cindex "listing" "messages in the queue"
3198 This option requests a listing of the contents of the mail queue on the
3199 standard output. If the &%-bp%& option is followed by a list of message ids,
3200 just those messages are listed. By default, this option can be used only by an
3201 admin user. However, the &%queue_list_requires_admin%& option can be set false
3202 to allow any user to see the queue.
3204 Each message in the queue is displayed as in the following example:
3205 .code
3206 25m 2.9K 0t5C6f-0000c8-00 <alice@wonderland.fict.example>
3207 red.king@looking-glass.fict.example
3208 <other addresses>
3209 .endd
3210 .cindex "message" "size in queue listing"
3211 .cindex "size" "of message"
3212 The first line contains the length of time the message has been in the queue
3213 (in this case 25 minutes), the size of the message (2.9K), the unique local
3214 identifier for the message, and the message sender, as contained in the
3215 envelope. For bounce messages, the sender address is empty, and appears as
3216 &"<>"&. If the message was submitted locally by an untrusted user who overrode
3217 the default sender address, the user's login name is shown in parentheses
3218 before the sender address.
3220 .cindex "frozen messages" "in queue listing"
3221 If the message is frozen (attempts to deliver it are suspended) then the text
3222 &"*** frozen ***"& is displayed at the end of this line.
3224 The recipients of the message (taken from the envelope, not the headers) are
3225 displayed on subsequent lines. Those addresses to which the message has already
3226 been delivered are marked with the letter D. If an original address gets
3227 expanded into several addresses via an alias or forward file, the original is
3228 displayed with a D only when deliveries for all of its child addresses are
3229 complete.
3232 .vitem &%-bpa%&
3233 .oindex "&%-bpa%&"
3234 This option operates like &%-bp%&, but in addition it shows delivered addresses
3235 that were generated from the original top level address(es) in each message by
3236 alias or forwarding operations. These addresses are flagged with &"+D"& instead
3237 of just &"D"&.
3240 .vitem &%-bpc%&
3241 .oindex "&%-bpc%&"
3242 .cindex "queue" "count of messages on"
3243 This option counts the number of messages in the queue, and writes the total
3244 to the standard output. It is restricted to admin users, unless
3245 &%queue_list_requires_admin%& is set false.
3248 .vitem &%-bpr%&
3249 .oindex "&%-bpr%&"
3250 This option operates like &%-bp%&, but the output is not sorted into
3251 chronological order of message arrival. This can speed it up when there are
3252 lots of messages in the queue, and is particularly useful if the output is
3253 going to be post-processed in a way that doesn't need the sorting.
3255 .vitem &%-bpra%&
3256 .oindex "&%-bpra%&"
3257 This option is a combination of &%-bpr%& and &%-bpa%&.
3259 .vitem &%-bpru%&
3260 .oindex "&%-bpru%&"
3261 This option is a combination of &%-bpr%& and &%-bpu%&.
3264 .vitem &%-bpu%&
3265 .oindex "&%-bpu%&"
3266 This option operates like &%-bp%& but shows only undelivered top-level
3267 addresses for each message displayed. Addresses generated by aliasing or
3268 forwarding are not shown, unless the message was deferred after processing by a
3269 router with the &%one_time%& option set.
3272 .vitem &%-brt%&
3273 .oindex "&%-brt%&"
3274 .cindex "testing" "retry configuration"
3275 .cindex "retry" "configuration testing"
3276 This option is for testing retry rules, and it must be followed by up to three
3277 arguments. It causes Exim to look for a retry rule that matches the values
3278 and to write it to the standard output. For example:
3279 .code
3280 exim -brt bach.comp.mus.example
3281 Retry rule: *.comp.mus.example F,2h,15m; F,4d,30m;
3282 .endd
3283 See chapter &<<CHAPretry>>& for a description of Exim's retry rules. The first
3284 argument, which is required, can be a complete address in the form
3285 &'local_part@domain'&, or it can be just a domain name. If the second argument
3286 contains a dot, it is interpreted as an optional second domain name; if no
3287 retry rule is found for the first argument, the second is tried. This ties in
3288 with Exim's behaviour when looking for retry rules for remote hosts &-- if no
3289 rule is found that matches the host, one that matches the mail domain is
3290 sought. Finally, an argument that is the name of a specific delivery error, as
3291 used in setting up retry rules, can be given. For example:
3292 .code
3293 exim -brt haydn.comp.mus.example quota_3d
3294 Retry rule: *@haydn.comp.mus.example quota_3d F,1h,15m
3295 .endd
3297 .vitem &%-brw%&
3298 .oindex "&%-brw%&"
3299 .cindex "testing" "rewriting"
3300 .cindex "rewriting" "testing"
3301 This option is for testing address rewriting rules, and it must be followed by
3302 a single argument, consisting of either a local part without a domain, or a
3303 complete address with a fully qualified domain. Exim outputs how this address
3304 would be rewritten for each possible place it might appear. See chapter
3305 &<<CHAPrewrite>>& for further details.
3307 .vitem &%-bS%&
3308 .oindex "&%-bS%&"
3309 .cindex "SMTP" "batched incoming"
3310 .cindex "batched SMTP input"
3311 This option is used for batched SMTP input, which is an alternative interface
3312 for non-interactive local message submission. A number of messages can be
3313 submitted in a single run. However, despite its name, this is not really SMTP
3314 input. Exim reads each message's envelope from SMTP commands on the standard
3315 input, but generates no responses. If the caller is trusted, or
3316 &%untrusted_set_sender%& is set, the senders in the SMTP MAIL commands are
3317 believed; otherwise the sender is always the caller of Exim.
3319 The message itself is read from the standard input, in SMTP format (leading
3320 dots doubled), terminated by a line containing just a single dot. An error is
3321 provoked if the terminating dot is missing. A further message may then follow.
3323 As for other local message submissions, the contents of incoming batch SMTP
3324 messages can be checked using the non-SMTP ACL (see chapter &<<CHAPACL>>&).
3325 Unqualified addresses are automatically qualified using &%qualify_domain%& and
3326 &%qualify_recipient%&, as appropriate, unless the &%-bnq%& option is used.
3328 Some other SMTP commands are recognized in the input. HELO and EHLO act
3329 as RSET; VRFY, EXPN, ETRN, and HELP act as NOOP;
3330 QUIT quits, ignoring the rest of the standard input.
3332 .cindex "return code" "for &%-bS%&"
3333 If any error is encountered, reports are written to the standard output and
3334 error streams, and Exim gives up immediately. The return code is 0 if no error
3335 was detected; it is 1 if one or more messages were accepted before the error
3336 was detected; otherwise it is 2.
3338 More details of input using batched SMTP are given in section
3339 &<<SECTincomingbatchedSMTP>>&.
3341 .vitem &%-bs%&
3342 .oindex "&%-bs%&"
3343 .cindex "SMTP" "local input"
3344 .cindex "local SMTP input"
3345 This option causes Exim to accept one or more messages by reading SMTP commands
3346 on the standard input, and producing SMTP replies on the standard output. SMTP
3347 policy controls, as defined in ACLs (see chapter &<<CHAPACL>>&) are applied.
3348 Some user agents use this interface as a way of passing locally-generated
3349 messages to the MTA.
3351 In
3352 .cindex "sender" "source of"
3353 this usage, if the caller of Exim is trusted, or &%untrusted_set_sender%& is
3354 set, the senders of messages are taken from the SMTP MAIL commands.
3355 Otherwise the content of these commands is ignored and the sender is set up as
3356 the calling user. Unqualified addresses are automatically qualified using
3357 &%qualify_domain%& and &%qualify_recipient%&, as appropriate, unless the
3358 &%-bnq%& option is used.
3360 .cindex "inetd"
3361 The
3362 &%-bs%& option is also used to run Exim from &'inetd'&, as an alternative to
3363 using a listening daemon. Exim can distinguish the two cases by checking
3364 whether the standard input is a TCP/IP socket. When Exim is called from
3365 &'inetd'&, the source of the mail is assumed to be remote, and the comments
3366 above concerning senders and qualification do not apply. In this situation,
3367 Exim behaves in exactly the same way as it does when receiving a message via
3368 the listening daemon.
3370 .vitem &%-bt%&
3371 .oindex "&%-bt%&"
3372 .cindex "testing" "addresses"
3373 .cindex "address" "testing"
3374 This option runs Exim in address testing mode, in which each argument is taken
3375 as a recipient address to be tested for deliverability. The results are
3376 written to the standard output. If a test fails, and the caller is not an admin
3377 user, no details of the failure are output, because these might contain
3378 sensitive information such as usernames and passwords for database lookups.
3380 If no arguments are given, Exim runs in an interactive manner, prompting with a
3381 right angle bracket for addresses to be tested.
3383 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3384 &[readline()]& function, because it is running as &'root'& and there are
3385 security issues.
3387 Each address is handled as if it were the recipient address of a message
3388 (compare the &%-bv%& option). It is passed to the routers and the result is
3389 written to the standard output. However, any router that has
3390 &%no_address_test%& set is bypassed. This can make &%-bt%& easier to use for
3391 genuine routing tests if your first router passes everything to a scanner
3392 program.
3394 .cindex "return code" "for &%-bt%&"
3395 The return code is 2 if any address failed outright; it is 1 if no address
3396 failed outright but at least one could not be resolved for some reason. Return
3397 code 0 is given only when all addresses succeed.
3399 .cindex "duplicate addresses"
3400 &*Note*&: When actually delivering a message, Exim removes duplicate recipient
3401 addresses after routing is complete, so that only one delivery takes place.
3402 This does not happen when testing with &%-bt%&; the full results of routing are
3403 always shown.
3405 &*Warning*&: &%-bt%& can only do relatively simple testing. If any of the
3406 routers in the configuration makes any tests on the sender address of a
3407 message,
3408 .oindex "&%-f%&" "for address testing"
3409 you can use the &%-f%& option to set an appropriate sender when running
3410 &%-bt%& tests. Without it, the sender is assumed to be the calling user at the
3411 default qualifying domain. However, if you have set up (for example) routers
3412 whose behaviour depends on the contents of an incoming message, you cannot test
3413 those conditions using &%-bt%&. The &%-N%& option provides a possible way of
3414 doing such tests.
3416 .vitem &%-bV%&
3417 .oindex "&%-bV%&"
3418 .cindex "version number of Exim"
3419 This option causes Exim to write the current version number, compilation
3420 number, and compilation date of the &'exim'& binary to the standard output.
3421 It also lists the DBM library that is being used, the optional modules (such as
3422 specific lookup types), the drivers that are included in the binary, and the
3423 name of the runtime configuration file that is in use.
3425 As part of its operation, &%-bV%& causes Exim to read and syntax check its
3426 configuration file. However, this is a static check only. It cannot check
3427 values that are to be expanded. For example, although a misspelt ACL verb is
3428 detected, an error in the verb's arguments is not. You cannot rely on &%-bV%&
3429 alone to discover (for example) all the typos in the configuration; some
3430 realistic testing is needed. The &%-bh%& and &%-N%& options provide more
3431 dynamic testing facilities.
3433 .vitem &%-bv%&
3434 .oindex "&%-bv%&"
3435 .cindex "verifying address" "using &%-bv%&"
3436 .cindex "address" "verification"
3437 This option runs Exim in address verification mode, in which each argument is
3438 taken as a recipient address to be verified by the routers. (This does
3439 not involve any verification callouts). During normal operation, verification
3440 happens mostly as a consequence processing a &%verify%& condition in an ACL
3441 (see chapter &<<CHAPACL>>&). If you want to test an entire ACL, possibly
3442 including callouts, see the &%-bh%& and &%-bhc%& options.
3444 If verification fails, and the caller is not an admin user, no details of the
3445 failure are output, because these might contain sensitive information such as
3446 usernames and passwords for database lookups.
3448 If no arguments are given, Exim runs in an interactive manner, prompting with a
3449 right angle bracket for addresses to be verified.
3451 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3452 &[readline()]& function, because it is running as &'exim'& and there are
3453 security issues.
3455 Verification differs from address testing (the &%-bt%& option) in that routers
3456 that have &%no_verify%& set are skipped, and if the address is accepted by a
3457 router that has &%fail_verify%& set, verification fails. The address is
3458 verified as a recipient if &%-bv%& is used; to test verification for a sender
3459 address, &%-bvs%& should be used.
3461 If the &%-v%& option is not set, the output consists of a single line for each
3462 address, stating whether it was verified or not, and giving a reason in the
3463 latter case. Without &%-v%&, generating more than one address by redirection
3464 causes verification to end successfully, without considering the generated
3465 addresses. However, if just one address is generated, processing continues,
3466 and the generated address must verify successfully for the overall verification
3467 to succeed.
3469 When &%-v%& is set, more details are given of how the address has been handled,
3470 and in the case of address redirection, all the generated addresses are also
3471 considered. Verification may succeed for some and fail for others.
3473 The
3474 .cindex "return code" "for &%-bv%&"
3475 return code is 2 if any address failed outright; it is 1 if no address
3476 failed outright but at least one could not be resolved for some reason. Return
3477 code 0 is given only when all addresses succeed.
3479 If any of the routers in the configuration makes any tests on the sender
3480 address of a message, you should use the &%-f%& option to set an appropriate
3481 sender when running &%-bv%& tests. Without it, the sender is assumed to be the
3482 calling user at the default qualifying domain.
3484 .vitem &%-bvs%&
3485 .oindex "&%-bvs%&"
3486 This option acts like &%-bv%&, but verifies the address as a sender rather
3487 than a recipient address. This affects any rewriting and qualification that
3488 might happen.
3490 .vitem &%-bw%&
3491 .oindex "&%-bw%&"
3492 .cindex "daemon"
3493 .cindex "inetd"
3494 .cindex "inetd" "wait mode"
3495 This option runs Exim as a daemon, awaiting incoming SMTP connections,
3496 similarly to the &%-bd%& option. All port specifications on the command-line
3497 and in the configuration file are ignored. Queue-running may not be specified.
3499 In this mode, Exim expects to be passed a socket as fd 0 (stdin) which is
3500 listening for connections. This permits the system to start up and have
3501 inetd (or equivalent) listen on the SMTP ports, starting an Exim daemon for
3502 each port only when the first connection is received.
3504 If the option is given as &%-bw%&<&'time'&> then the time is a timeout, after
3505 which the daemon will exit, which should cause inetd to listen once more.
3507 .vitem &%-C%&&~<&'filelist'&>
3508 .oindex "&%-C%&"
3509 .cindex "configuration file" "alternate"
3510 .cindex "CONFIGURE_FILE"
3511 .cindex "alternate configuration file"
3512 This option causes Exim to find the runtime configuration file from the given
3513 list instead of from the list specified by the CONFIGURE_FILE
3514 compile-time setting. Usually, the list will consist of just a single filename,
3515 but it can be a colon-separated list of names. In this case, the first
3516 file that exists is used. Failure to open an existing file stops Exim from
3517 proceeding any further along the list, and an error is generated.
3519 When this option is used by a caller other than root, and the list is different
3520 from the compiled-in list, Exim gives up its root privilege immediately, and
3521 runs with the real and effective uid and gid set to those of the caller.
3522 However, if a TRUSTED_CONFIG_LIST file is defined in &_Local/Makefile_&, that
3523 file contains a list of full pathnames, one per line, for configuration files
3524 which are trusted. Root privilege is retained for any configuration file so
3525 listed, as long as the caller is the Exim user (or the user specified in the
3526 CONFIGURE_OWNER option, if any), and as long as the configuration file is
3527 not writeable by inappropriate users or groups.
3529 Leaving TRUSTED_CONFIG_LIST unset precludes the possibility of testing a
3530 configuration using &%-C%& right through message reception and delivery,
3531 even if the caller is root. The reception works, but by that time, Exim is
3532 running as the Exim user, so when it re-executes to regain privilege for the
3533 delivery, the use of &%-C%& causes privilege to be lost. However, root can
3534 test reception and delivery using two separate commands (one to put a message
3535 in the queue, using &%-odq%&, and another to do the delivery, using &%-M%&).
3537 If ALT_CONFIG_PREFIX is defined &_in Local/Makefile_&, it specifies a
3538 prefix string with which any file named in a &%-C%& command line option
3539 must start. In addition, the filename must not contain the sequence &`/../`&.
3540 However, if the value of the &%-C%& option is identical to the value of
3541 CONFIGURE_FILE in &_Local/Makefile_&, Exim ignores &%-C%& and proceeds as
3542 usual. There is no default setting for ALT_CONFIG_PREFIX; when it is
3543 unset, any filename can be used with &%-C%&.
3545 ALT_CONFIG_PREFIX can be used to confine alternative configuration files
3546 to a directory to which only root has access. This prevents someone who has
3547 broken into the Exim account from running a privileged Exim with an arbitrary
3548 configuration file.
3550 The &%-C%& facility is useful for ensuring that configuration files are
3551 syntactically correct, but cannot be used for test deliveries, unless the
3552 caller is privileged, or unless it is an exotic configuration that does not
3553 require privilege. No check is made on the owner or group of the files
3554 specified by this option.
3557 .vitem &%-D%&<&'macro'&>=<&'value'&>
3558 .oindex "&%-D%&"
3559 .cindex "macro" "setting on command line"
3560 This option can be used to override macro definitions in the configuration file
3561 (see section &<<SECTmacrodefs>>&). However, like &%-C%&, if it is used by an
3562 unprivileged caller, it causes Exim to give up its root privilege.
3563 If DISABLE_D_OPTION is defined in &_Local/Makefile_&, the use of &%-D%& is
3564 completely disabled, and its use causes an immediate error exit.
3566 If WHITELIST_D_MACROS is defined in &_Local/Makefile_& then it should be a
3567 colon-separated list of macros which are considered safe and, if &%-D%& only
3568 supplies macros from this list, and the values are acceptable, then Exim will
3569 not give up root privilege if the caller is root, the Exim run-time user, or
3570 the CONFIGURE_OWNER, if set. This is a transition mechanism and is expected
3571 to be removed in the future. Acceptable values for the macros satisfy the
3572 regexp: &`^[A-Za-z0-9_/.-]*$`&
3574 The entire option (including equals sign if present) must all be within one
3575 command line item. &%-D%& can be used to set the value of a macro to the empty
3576 string, in which case the equals sign is optional. These two commands are
3577 synonymous:
3578 .code
3579 exim -DABC ...
3580 exim -DABC= ...
3581 .endd
3582 To include spaces in a macro definition item, quotes must be used. If you use
3583 quotes, spaces are permitted around the macro name and the equals sign. For
3584 example:
3585 .code
3586 exim '-D ABC = something' ...
3587 .endd
3588 &%-D%& may be repeated up to 10 times on a command line.
3589 Only macro names up to 22 letters long can be set.
3592 .vitem &%-d%&<&'debug&~options'&>
3593 .oindex "&%-d%&"
3594 .cindex "debugging" "list of selectors"
3595 .cindex "debugging" "&%-d%& option"
3596 This option causes debugging information to be written to the standard
3597 error stream. It is restricted to admin users because debugging output may show
3598 database queries that contain password information. Also, the details of users'
3599 filter files should be protected. If a non-admin user uses &%-d%&, Exim
3600 writes an error message to the standard error stream and exits with a non-zero
3601 return code.
3603 When &%-d%& is used, &%-v%& is assumed. If &%-d%& is given on its own, a lot of
3604 standard debugging data is output. This can be reduced, or increased to include
3605 some more rarely needed information, by directly following &%-d%& with a string
3606 made up of names preceded by plus or minus characters. These add or remove sets
3607 of debugging data, respectively. For example, &%-d+filter%& adds filter
3608 debugging, whereas &%-d-all+filter%& selects only filter debugging. Note that
3609 no spaces are allowed in the debug setting. The available debugging categories
3610 are:
3611 .display
3612 &`acl `& ACL interpretation
3613 &`auth `& authenticators
3614 &`deliver `& general delivery logic
3615 &`dns `& DNS lookups (see also resolver)
3616 &`dnsbl `& DNS black list (aka RBL) code
3617 &`exec `& arguments for &[execv()]& calls
3618 &`expand `& detailed debugging for string expansions
3619 &`filter `& filter handling
3620 &`hints_lookup `& hints data lookups
3621 &`host_lookup `& all types of name-to-IP address handling
3622 &`ident `& ident lookup
3623 &`interface `& lists of local interfaces
3624 &`lists `& matching things in lists
3625 &`load `& system load checks
3626 &`local_scan `& can be used by &[local_scan()]& (see chapter &&&
3627 &<<CHAPlocalscan>>&)
3628 &`lookup `& general lookup code and all lookups
3629 &`memory `& memory handling
3630 &`noutf8 `& modifier: avoid UTF-8 line-drawing
3631 &`pid `& modifier: add pid to debug output lines
3632 &`process_info `& setting info for the process log
3633 &`queue_run `& queue runs
3634 &`receive `& general message reception logic
3635 &`resolver `& turn on the DNS resolver's debugging output
3636 &`retry `& retry handling
3637 &`rewrite `& address rewriting
3638 &`route `& address routing
3639 &`timestamp `& modifier: add timestamp to debug output lines
3640 &`tls `& TLS logic
3641 &`transport `& transports
3642 &`uid `& changes of uid/gid and looking up uid/gid
3643 &`verify `& address verification logic
3644 &`all `& almost all of the above (see below), and also &%-v%&
3645 .endd
3646 The &`all`& option excludes &`memory`& when used as &`+all`&, but includes it
3647 for &`-all`&. The reason for this is that &`+all`& is something that people
3648 tend to use when generating debug output for Exim maintainers. If &`+memory`&
3649 is included, an awful lot of output that is very rarely of interest is
3650 generated, so it now has to be explicitly requested. However, &`-all`& does
3651 turn everything off.
3653 .cindex "resolver, debugging output"
3654 .cindex "DNS resolver, debugging output"
3655 The &`resolver`& option produces output only if the DNS resolver was compiled
3656 with DEBUG enabled. This is not the case in some operating systems. Also,
3657 unfortunately, debugging output from the DNS resolver is written to stdout
3658 rather than stderr.
3660 The default (&%-d%& with no argument) omits &`expand`&, &`filter`&,
3661 &`interface`&, &`load`&, &`memory`&, &`pid`&, &`resolver`&, and &`timestamp`&.
3662 However, the &`pid`& selector is forced when debugging is turned on for a
3663 daemon, which then passes it on to any re-executed Exims. Exim also
3664 automatically adds the pid to debug lines when several remote deliveries are
3665 run in parallel.
3667 The &`timestamp`& selector causes the current time to be inserted at the start
3668 of all debug output lines. This can be useful when trying to track down delays
3669 in processing.
3671 .cindex debugging "UTF-8 in"
3672 .cindex UTF-8 "in debug output"
3673 The &`noutf8`& selector disables the use of
3674 UTF-8 line-drawing characters to group related information.
3675 When disabled. ascii-art is used instead.
3676 Using the &`+all`& option does not set this modifier,
3678 If the &%debug_print%& option is set in any driver, it produces output whenever
3679 any debugging is selected, or if &%-v%& is used.
3681 .vitem &%-dd%&<&'debug&~options'&>
3682 .oindex "&%-dd%&"
3683 This option behaves exactly like &%-d%& except when used on a command that
3684 starts a daemon process. In that case, debugging is turned off for the
3685 subprocesses that the daemon creates. Thus, it is useful for monitoring the
3686 behaviour of the daemon without creating as much output as full debugging does.
3688 .vitem &%-dropcr%&
3689 .oindex "&%-dropcr%&"
3690 This is an obsolete option that is now a no-op. It used to affect the way Exim
3691 handled CR and LF characters in incoming messages. What happens now is
3692 described in section &<<SECTlineendings>>&.
3694 .vitem &%-E%&
3695 .oindex "&%-E%&"
3696 .cindex "bounce message" "generating"
3697 This option specifies that an incoming message is a locally-generated delivery
3698 failure report. It is used internally by Exim when handling delivery failures
3699 and is not intended for external use. Its only effect is to stop Exim
3700 generating certain messages to the postmaster, as otherwise message cascades
3701 could occur in some situations. As part of the same option, a message id may
3702 follow the characters &%-E%&. If it does, the log entry for the receipt of the
3703 new message contains the id, following &"R="&, as a cross-reference.
3705 .vitem &%-e%&&'x'&
3706 .oindex "&%-e%&&'x'&"
3707 There are a number of Sendmail options starting with &%-oe%& which seem to be
3708 called by various programs without the leading &%o%& in the option. For
3709 example, the &%vacation%& program uses &%-eq%&. Exim treats all options of the
3710 form &%-e%&&'x'& as synonymous with the corresponding &%-oe%&&'x'& options.
3712 .vitem &%-F%&&~<&'string'&>
3713 .oindex "&%-F%&"
3714 .cindex "sender" "name"
3715 .cindex "name" "of sender"
3716 This option sets the sender's full name for use when a locally-generated
3717 message is being accepted. In the absence of this option, the user's &'gecos'&
3718 entry from the password data is used. As users are generally permitted to alter
3719 their &'gecos'& entries, no security considerations are involved. White space
3720 between &%-F%& and the <&'string'&> is optional.
3722 .vitem &%-f%&&~<&'address'&>
3723 .oindex "&%-f%&"
3724 .cindex "sender" "address"
3725 .cindex "address" "sender"
3726 .cindex "trusted users"
3727 .cindex "envelope from"
3728 .cindex "envelope sender"
3729 .cindex "user" "trusted"
3730 This option sets the address of the envelope sender of a locally-generated
3731 message (also known as the return path). The option can normally be used only
3732 by a trusted user, but &%untrusted_set_sender%& can be set to allow untrusted
3733 users to use it.
3735 Processes running as root or the Exim user are always trusted. Other
3736 trusted users are defined by the &%trusted_users%& or &%trusted_groups%&
3737 options. In the absence of &%-f%&, or if the caller is not trusted, the sender
3738 of a local message is set to the caller's login name at the default qualify
3739 domain.
3741 There is one exception to the restriction on the use of &%-f%&: an empty sender
3742 can be specified by any user, trusted or not, to create a message that can
3743 never provoke a bounce. An empty sender can be specified either as an empty
3744 string, or as a pair of angle brackets with nothing between them, as in these
3745 examples of shell commands:
3746 .code
3747 exim -f '<>' user@domain
3748 exim -f "" user@domain
3749 .endd
3750 In addition, the use of &%-f%& is not restricted when testing a filter file
3751 with &%-bf%& or when testing or verifying addresses using the &%-bt%& or
3752 &%-bv%& options.
3754 Allowing untrusted users to change the sender address does not of itself make
3755 it possible to send anonymous mail. Exim still checks that the &'From:'& header
3756 refers to the local user, and if it does not, it adds a &'Sender:'& header,
3757 though this can be overridden by setting &%no_local_from_check%&.
3759 White
3760 .cindex "&""From""& line"
3761 space between &%-f%& and the <&'address'&> is optional (that is, they can be
3762 given as two arguments or one combined argument). The sender of a
3763 locally-generated message can also be set (when permitted) by an initial
3764 &"From&~"& line in the message &-- see the description of &%-bm%& above &-- but
3765 if &%-f%& is also present, it overrides &"From&~"&.
3767 .vitem &%-G%&
3768 .oindex "&%-G%&"
3769 .cindex "submission fixups, suppressing (command-line)"
3770 This option is equivalent to an ACL applying:
3771 .code
3772 control = suppress_local_fixups
3773 .endd
3774 for every message received. Note that Sendmail will complain about such
3775 bad formatting, where Exim silently just does not fix it up. This may change
3776 in future.
3778 As this affects audit information, the caller must be a trusted user to use
3779 this option.
3781 .vitem &%-h%&&~<&'number'&>
3782 .oindex "&%-h%&"
3783 .cindex "Sendmail compatibility" "&%-h%& option ignored"
3784 This option is accepted for compatibility with Sendmail, but has no effect. (In
3785 Sendmail it overrides the &"hop count"& obtained by counting &'Received:'&
3786 headers.)
3788 .vitem &%-i%&
3789 .oindex "&%-i%&"
3790 .cindex "Solaris" "&'mail'& command"
3791 .cindex "dot" "in incoming non-SMTP message"
3792 This option, which has the same effect as &%-oi%&, specifies that a dot on a
3793 line by itself should not terminate an incoming, non-SMTP message. I can find
3794 no documentation for this option in Solaris 2.4 Sendmail, but the &'mailx'&
3795 command in Solaris 2.4 uses it. See also &%-ti%&.
3797 .vitem &%-L%&&~<&'tag'&>
3798 .oindex "&%-L%&"
3799 .cindex "syslog" "process name; set with flag"
3800 This option is equivalent to setting &%syslog_processname%& in the config
3801 file and setting &%log_file_path%& to &`syslog`&.
3802 Its use is restricted to administrators. The configuration file has to be
3803 read and parsed, to determine access rights, before this is set and takes
3804 effect, so early configuration file errors will not honour this flag.
3806 The tag should not be longer than 32 characters.
3808 .vitem &%-M%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3809 .oindex "&%-M%&"
3810 .cindex "forcing delivery"
3811 .cindex "delivery" "forcing attempt"
3812 .cindex "frozen messages" "forcing delivery"
3813 This option requests Exim to run a delivery attempt on each message in turn. If
3814 any of the messages are frozen, they are automatically thawed before the
3815 delivery attempt. The settings of &%queue_domains%&, &%queue_smtp_domains%&,
3816 and &%hold_domains%& are ignored.
3818 Retry
3819 .cindex "hints database" "overriding retry hints"
3820 hints for any of the addresses are overridden &-- Exim tries to deliver even if
3821 the normal retry time has not yet been reached. This option requires the caller
3822 to be an admin user. However, there is an option called &%prod_requires_admin%&
3823 which can be set false to relax this restriction (and also the same requirement
3824 for the &%-q%&, &%-R%&, and &%-S%& options).
3826 The deliveries happen synchronously, that is, the original Exim process does
3827 not terminate until all the delivery attempts have finished. No output is
3828 produced unless there is a serious error. If you want to see what is happening,
3829 use the &%-v%& option as well, or inspect Exim's main log.
3831 .vitem &%-Mar%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
3832 .oindex "&%-Mar%&"
3833 .cindex "message" "adding recipients"
3834 .cindex "recipient" "adding"
3835 This option requests Exim to add the addresses to the list of recipients of the
3836 message (&"ar"& for &"add recipients"&). The first argument must be a message
3837 id, and the remaining ones must be email addresses. However, if the message is
3838 active (in the middle of a delivery attempt), it is not altered. This option
3839 can be used only by an admin user.
3841 .vitem "&%-MC%&&~<&'transport'&>&~<&'hostname'&>&~<&'sequence&~number'&>&&&
3842 &~<&'message&~id'&>"
3843 .oindex "&%-MC%&"
3844 .cindex "SMTP" "passed connection"
3845 .cindex "SMTP" "multiple deliveries"
3846 .cindex "multiple SMTP deliveries"
3847 This option is not intended for use by external callers. It is used internally
3848 by Exim to invoke another instance of itself to deliver a waiting message using
3849 an existing SMTP connection, which is passed as the standard input. Details are
3850 given in chapter &<<CHAPSMTP>>&. This must be the final option, and the caller
3851 must be root or the Exim user in order to use it.
3853 .vitem &%-MCA%&
3854 .oindex "&%-MCA%&"
3855 This option is not intended for use by external callers. It is used internally
3856 by Exim in conjunction with the &%-MC%& option. It signifies that the
3857 connection to the remote host has been authenticated.
3859 .vitem &%-MCD%&
3860 .oindex "&%-MCD%&"
3861 This option is not intended for use by external callers. It is used internally
3862 by Exim in conjunction with the &%-MC%& option. It signifies that the
3863 remote host supports the ESMTP &_DSN_& extension.
3865 .vitem &%-MCG%&&~<&'queue&~name'&>
3866 .oindex "&%-MCG%&"
3867 This option is not intended for use by external callers. It is used internally
3868 by Exim in conjunction with the &%-MC%& option. It signifies that an
3869 alternate queue is used, named by the following argument.
3871 .vitem &%-MCK%&
3872 .oindex "&%-MCK%&"
3873 This option is not intended for use by external callers. It is used internally
3874 by Exim in conjunction with the &%-MC%& option. It signifies that a
3875 remote host supports the ESMTP &_CHUNKING_& extension.
3877 .vitem &%-MCP%&
3878 .oindex "&%-MCP%&"
3879 This option is not intended for use by external callers. It is used internally
3880 by Exim in conjunction with the &%-MC%& option. It signifies that the server to
3881 which Exim is connected supports pipelining.
3883 .vitem &%-MCQ%&&~<&'process&~id'&>&~<&'pipe&~fd'&>
3884 .oindex "&%-MCQ%&"
3885 This option is not intended for use by external callers. It is used internally
3886 by Exim in conjunction with the &%-MC%& option when the original delivery was
3887 started by a queue runner. It passes on the process id of the queue runner,
3888 together with the file descriptor number of an open pipe. Closure of the pipe
3889 signals the final completion of the sequence of processes that are passing
3890 messages through the same SMTP connection.
3892 .vitem &%-MCS%&
3893 .oindex "&%-MCS%&"
3894 This option is not intended for use by external callers. It is used internally
3895 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3896 SMTP SIZE option should be used on messages delivered down the existing
3897 connection.
3899 .vitem &%-MCT%&
3900 .oindex "&%-MCT%&"
3901 This option is not intended for use by external callers. It is used internally
3902 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3903 host to which Exim is connected supports TLS encryption.
3905 .vitem &%-MCt%&&~<&'IP&~address'&>&~<&'port'&>&~<&'cipher'&>
3906 .oindex "&%-MCt%&"
3907 This option is not intended for use by external callers. It is used internally
3908 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3909 connection is being proxied by a parent process for handling TLS encryption.
3910 The arguments give the local address and port being proxied, and the TLS cipher.
3912 .vitem &%-Mc%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3913 .oindex "&%-Mc%&"
3914 .cindex "hints database" "not overridden by &%-Mc%&"
3915 .cindex "delivery" "manually started &-- not forced"
3916 This option requests Exim to run a delivery attempt on each message, in turn,
3917 but unlike the &%-M%& option, it does check for retry hints, and respects any
3918 that are found. This option is not very useful to external callers. It is
3919 provided mainly for internal use by Exim when it needs to re-invoke itself in
3920 order to regain root privilege for a delivery (see chapter &<<CHAPsecurity>>&).
3921 However, &%-Mc%& can be useful when testing, in order to run a delivery that
3922 respects retry times and other options such as &%hold_domains%& that are
3923 overridden when &%-M%& is used. Such a delivery does not count as a queue run.
3924 If you want to run a specific delivery as if in a queue run, you should use
3925 &%-q%& with a message id argument. A distinction between queue run deliveries
3926 and other deliveries is made in one or two places.
3928 .vitem &%-Mes%&&~<&'message&~id'&>&~<&'address'&>
3929 .oindex "&%-Mes%&"
3930 .cindex "message" "changing sender"
3931 .cindex "sender" "changing"
3932 This option requests Exim to change the sender address in the message to the
3933 given address, which must be a fully qualified address or &"<>"& (&"es"& for
3934 &"edit sender"&). There must be exactly two arguments. The first argument must
3935 be a message id, and the second one an email address. However, if the message
3936 is active (in the middle of a delivery attempt), its status is not altered.
3937 This option can be used only by an admin user.
3939 .vitem &%-Mf%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3940 .oindex "&%-Mf%&"
3941 .cindex "freezing messages"
3942 .cindex "message" "manually freezing"
3943 This option requests Exim to mark each listed message as &"frozen"&. This
3944 prevents any delivery attempts taking place until the message is &"thawed"&,
3945 either manually or as a result of the &%auto_thaw%& configuration option.
3946 However, if any of the messages are active (in the middle of a delivery
3947 attempt), their status is not altered. This option can be used only by an admin
3948 user.
3950 .vitem &%-Mg%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3951 .oindex "&%-Mg%&"
3952 .cindex "giving up on messages"
3953 .cindex "message" "abandoning delivery attempts"
3954 .cindex "delivery" "abandoning further attempts"
3955 This option requests Exim to give up trying to deliver the listed messages,
3956 including any that are frozen. However, if any of the messages are active,
3957 their status is not altered. For non-bounce messages, a delivery error message
3958 is sent to the sender, containing the text &"cancelled by administrator"&.
3959 Bounce messages are just discarded. This option can be used only by an admin
3960 user.
3962 .vitem &%-Mmad%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3963 .oindex "&%-Mmad%&"
3964 .cindex "delivery" "cancelling all"
3965 This option requests Exim to mark all the recipient addresses in the messages
3966 as already delivered (&"mad"& for &"mark all delivered"&). However, if any
3967 message is active (in the middle of a delivery attempt), its status is not
3968 altered. This option can be used only by an admin user.
3970 .vitem &%-Mmd%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
3971 .oindex "&%-Mmd%&"
3972 .cindex "delivery" "cancelling by address"
3973 .cindex "recipient" "removing"
3974 .cindex "removing recipients"
3975 This option requests Exim to mark the given addresses as already delivered
3976 (&"md"& for &"mark delivered"&). The first argument must be a message id, and
3977 the remaining ones must be email addresses. These are matched to recipient
3978 addresses in the message in a case-sensitive manner. If the message is active
3979 (in the middle of a delivery attempt), its status is not altered. This option
3980 can be used only by an admin user.
3982 .vitem &%-Mrm%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3983 .oindex "&%-Mrm%&"
3984 .cindex "removing messages"
3985 .cindex "abandoning mail"
3986 .cindex "message" "manually discarding"
3987 This option requests Exim to remove the given messages from the queue. No
3988 bounce messages are sent; each message is simply forgotten. However, if any of
3989 the messages are active, their status is not altered. This option can be used
3990 only by an admin user or by the user who originally caused the message to be
3991 placed in the queue.
3993 . .new
3994 . .vitem &%-MS%&
3995 . .oindex "&%-MS%&"
3996 . .cindex REQUIRETLS
3997 . This option is used to request REQUIRETLS processing on the message.
3998 . It is used internally by Exim in conjunction with -E when generating
3999 . a bounce message.
4000 . .wen
4002 .vitem &%-Mset%&&~<&'message&~id'&>
4003 .oindex "&%-Mset%&"
4004 .cindex "testing" "string expansion"
4005 .cindex "expansion" "testing"
4006 This option is useful only in conjunction with &%-be%& (that is, when testing
4007 string expansions). Exim loads the given message from its spool before doing
4008 the test expansions, thus setting message-specific variables such as
4009 &$message_size$& and the header variables. The &$recipients$& variable is made
4010 available. This feature is provided to make it easier to test expansions that
4011 make use of these variables. However, this option can be used only by an admin
4012 user. See also &%-bem%&.
4014 .vitem &%-Mt%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
4015 .oindex "&%-Mt%&"
4016 .cindex "thawing messages"
4017 .cindex "unfreezing messages"
4018 .cindex "frozen messages" "thawing"
4019 .cindex "message" "thawing frozen"
4020 This option requests Exim to &"thaw"& any of the listed messages that are
4021 &"frozen"&, so that delivery attempts can resume. However, if any of the
4022 messages are active, their status is not altered. This option can be used only
4023 by an admin user.
4025 .vitem &%-Mvb%&&~<&'message&~id'&>
4026 .oindex "&%-Mvb%&"
4027 .cindex "listing" "message body"
4028 .cindex "message" "listing body of"
4029 This option causes the contents of the message body (-D) spool file to be
4030 written to the standard output. This option can be used only by an admin user.
4032 .vitem &%-Mvc%&&~<&'message&~id'&>
4033 .oindex "&%-Mvc%&"
4034 .cindex "message" "listing in RFC 2822 format"
4035 .cindex "listing" "message in RFC 2822 format"
4036 This option causes a copy of the complete message (header lines plus body) to
4037 be written to the standard output in RFC 2822 format. This option can be used
4038 only by an admin user.
4040 .vitem &%-Mvh%&&~<&'message&~id'&>
4041 .oindex "&%-Mvh%&"
4042 .cindex "listing" "message headers"
4043 .cindex "header lines" "listing"
4044 .cindex "message" "listing header lines"
4045 This option causes the contents of the message headers (-H) spool file to be
4046 written to the standard output. This option can be used only by an admin user.
4048 .vitem &%-Mvl%&&~<&'message&~id'&>
4049 .oindex "&%-Mvl%&"
4050 .cindex "listing" "message log"
4051 .cindex "message" "listing message log"
4052 This option causes the contents of the message log spool file to be written to
4053 the standard output. This option can be used only by an admin user.
4055 .vitem &%-m%&
4056 .oindex "&%-m%&"
4057 This is apparently a synonym for &%-om%& that is accepted by Sendmail, so Exim
4058 treats it that way too.
4060 .vitem &%-N%&
4061 .oindex "&%-N%&"
4062 .cindex "debugging" "&%-N%& option"
4063 .cindex "debugging" "suppressing delivery"
4064 This is a debugging option that inhibits delivery of a message at the transport
4065 level. It implies &%-v%&. Exim goes through many of the motions of delivery &--
4066 it just doesn't actually transport the message, but instead behaves as if it
4067 had successfully done so. However, it does not make any updates to the retry
4068 database, and the log entries for deliveries are flagged with &"*>"& rather
4069 than &"=>"&.
4071 Because &%-N%& discards any message to which it applies, only root or the Exim
4072 user are allowed to use it with &%-bd%&, &%-q%&, &%-R%& or &%-M%&. In other
4073 words, an ordinary user can use it only when supplying an incoming message to
4074 which it will apply. Although transportation never fails when &%-N%& is set, an
4075 address may be deferred because of a configuration problem on a transport, or a
4076 routing problem. Once &%-N%& has been used for a delivery attempt, it sticks to
4077 the message, and applies to any subsequent delivery attempts that may happen
4078 for that message.
4080 .vitem &%-n%&
4081 .oindex "&%-n%&"
4082 This option is interpreted by Sendmail to mean &"no aliasing"&.
4083 For normal modes of operation, it is ignored by Exim.
4084 When combined with &%-bP%& it makes the output more terse (suppresses
4085 option names, environment values and config pretty printing).
4087 .vitem &%-O%&&~<&'data'&>
4088 .oindex "&%-O%&"
4089 This option is interpreted by Sendmail to mean &`set option`&. It is ignored by
4090 Exim.
4092 .vitem &%-oA%&&~<&'file&~name'&>
4093 .oindex "&%-oA%&"
4094 .cindex "Sendmail compatibility" "&%-oA%& option"
4095 This option is used by Sendmail in conjunction with &%-bi%& to specify an
4096 alternative alias filename. Exim handles &%-bi%& differently; see the
4097 description above.
4099 .vitem &%-oB%&&~<&'n'&>
4100 .oindex "&%-oB%&"
4101 .cindex "SMTP" "passed connection"
4102 .cindex "SMTP" "multiple deliveries"
4103 .cindex "multiple SMTP deliveries"
4104 This is a debugging option which limits the maximum number of messages that can
4105 be delivered down one SMTP connection, overriding the value set in any &(smtp)&
4106 transport. If <&'n'&> is omitted, the limit is set to 1.
4108 .vitem &%-odb%&
4109 .oindex "&%-odb%&"
4110 .cindex "background delivery"
4111 .cindex "delivery" "in the background"
4112 This option applies to all modes in which Exim accepts incoming messages,
4113 including the listening daemon. It requests &"background"& delivery of such
4114 messages, which means that the accepting process automatically starts a
4115 delivery process for each message received, but does not wait for the delivery
4116 processes to finish.
4118 When all the messages have been received, the reception process exits,
4119 leaving the delivery processes to finish in their own time. The standard output
4120 and error streams are closed at the start of each delivery process.
4121 This is the default action if none of the &%-od%& options are present.
4123 If one of the queueing options in the configuration file
4124 (&%queue_only%& or &%queue_only_file%&, for example) is in effect, &%-odb%&
4125 overrides it if &%queue_only_override%& is set true, which is the default
4126 setting. If &%queue_only_override%& is set false, &%-odb%& has no effect.
4128 .vitem &%-odf%&
4129 .oindex "&%-odf%&"
4130 .cindex "foreground delivery"
4131 .cindex "delivery" "in the foreground"
4132 This option requests &"foreground"& (synchronous) delivery when Exim has
4133 accepted a locally-generated message. (For the daemon it is exactly the same as
4134 &%-odb%&.) A delivery process is automatically started to deliver the message,
4135 and Exim waits for it to complete before proceeding.
4137 The original Exim reception process does not finish until the delivery
4138 process for the final message has ended. The standard error stream is left open
4139 during deliveries.
4141 However, like &%-odb%&, this option has no effect if &%queue_only_override%& is
4142 false and one of the queueing options in the configuration file is in effect.
4144 If there is a temporary delivery error during foreground delivery, the
4145 message is left in the queue for later delivery, and the original reception
4146 process exits. See chapter &<<CHAPnonqueueing>>& for a way of setting up a
4147 restricted configuration that never queues messages.
4150 .vitem &%-odi%&
4151 .oindex "&%-odi%&"
4152 This option is synonymous with &%-odf%&. It is provided for compatibility with
4153 Sendmail.
4155 .vitem &%-odq%&
4156 .oindex "&%-odq%&"
4157 .cindex "non-immediate delivery"
4158 .cindex "delivery" "suppressing immediate"
4159 .cindex "queueing incoming messages"
4160 This option applies to all modes in which Exim accepts incoming messages,
4161 including the listening daemon. It specifies that the accepting process should
4162 not automatically start a delivery process for each message received. Messages
4163 are placed in the queue, and remain there until a subsequent queue runner
4164 process encounters them. There are several configuration options (such as
4165 &%queue_only%&) that can be used to queue incoming messages under certain
4166 conditions. This option overrides all of them and also &%-odqs%&. It always
4167 forces queueing.
4169 .vitem &%-odqs%&
4170 .oindex "&%-odqs%&"
4171 .cindex "SMTP" "delaying delivery"
4172 This option is a hybrid between &%-odb%&/&%-odi%& and &%-odq%&.
4173 However, like &%-odb%& and &%-odi%&, this option has no effect if
4174 &%queue_only_override%& is false and one of the queueing options in the
4175 configuration file is in effect.
4177 When &%-odqs%& does operate, a delivery process is started for each incoming
4178 message, in the background by default, but in the foreground if &%-odi%& is
4179 also present. The recipient addresses are routed, and local deliveries are done
4180 in the normal way. However, if any SMTP deliveries are required, they are not
4181 done at this time, so the message remains in the queue until a subsequent queue
4182 runner process encounters it. Because routing was done, Exim knows which
4183 messages are waiting for which hosts, and so a number of messages for the same
4184 host can be sent in a single SMTP connection. The &%queue_smtp_domains%&
4185 configuration option has the same effect for specific domains. See also the
4186 &%-qq%& option.
4188 .vitem &%-oee%&
4189 .oindex "&%-oee%&"
4190 .cindex "error" "reporting"
4191 If an error is detected while a non-SMTP message is being received (for
4192 example, a malformed address), the error is reported to the sender in a mail
4193 message.
4195 .cindex "return code" "for &%-oee%&"
4196 Provided
4197 this error message is successfully sent, the Exim receiving process
4198 exits with a return code of zero. If not, the return code is 2 if the problem
4199 is that the original message has no recipients, or 1 for any other error.
4200 This is the default &%-oe%&&'x'& option if Exim is called as &'rmail'&.
4202 .vitem &%-oem%&
4203 .oindex "&%-oem%&"
4204 .cindex "error" "reporting"
4205 .cindex "return code" "for &%-oem%&"
4206 This is the same as &%-oee%&, except that Exim always exits with a non-zero
4207 return code, whether or not the error message was successfully sent.
4208 This is the default &%-oe%&&'x'& option, unless Exim is called as &'rmail'&.
4210 .vitem &%-oep%&
4211 .oindex "&%-oep%&"
4212 .cindex "error" "reporting"
4213 If an error is detected while a non-SMTP message is being received, the
4214 error is reported by writing a message to the standard error file (stderr).
4215 .cindex "return code" "for &%-oep%&"
4216 The return code is 1 for all errors.
4218 .vitem &%-oeq%&
4219 .oindex "&%-oeq%&"
4220 .cindex "error" "reporting"
4221 This option is supported for compatibility with Sendmail, but has the same
4222 effect as &%-oep%&.
4224 .vitem &%-oew%&
4225 .oindex "&%-oew%&"
4226 .cindex "error" "reporting"
4227 This option is supported for compatibility with Sendmail, but has the same
4228 effect as &%-oem%&.
4230 .vitem &%-oi%&
4231 .oindex "&%-oi%&"
4232 .cindex "dot" "in incoming non-SMTP message"
4233 This option, which has the same effect as &%-i%&, specifies that a dot on a
4234 line by itself should not terminate an incoming, non-SMTP message. Otherwise, a
4235 single dot does terminate, though Exim does no special processing for other
4236 lines that start with a dot. This option is set by default if Exim is called as
4237 &'rmail'&. See also &%-ti%&.
4239 .vitem &%-oitrue%&
4240 .oindex "&%-oitrue%&"
4241 This option is treated as synonymous with &%-oi%&.
4243 .vitem &%-oMa%&&~<&'host&~address'&>
4244 .oindex "&%-oMa%&"
4245 .cindex "sender" "host address, specifying for local message"
4246 A number of options starting with &%-oM%& can be used to set values associated
4247 with remote hosts on locally-submitted messages (that is, messages not received
4248 over TCP/IP). These options can be used by any caller in conjunction with the
4249 &%-bh%&, &%-be%&, &%-bf%&, &%-bF%&, &%-bt%&, or &%-bv%& testing options. In
4250 other circumstances, they are ignored unless the caller is trusted.
4252 The &%-oMa%& option sets the sender host address. This may include a port
4253 number at the end, after a full stop (period). For example:
4254 .code
4255 exim -bs -oMa
4256 .endd
4257 An alternative syntax is to enclose the IP address in square brackets,
4258 followed by a colon and the port number:
4259 .code
4260 exim -bs -oMa []:1234
4261 .endd
4262 The IP address is placed in the &$sender_host_address$& variable, and the
4263 port, if present, in &$sender_host_port$&. If both &%-oMa%& and &%-bh%&
4264 are present on the command line, the sender host IP address is taken from
4265 whichever one is last.
4267 .vitem &%-oMaa%&&~<&'name'&>
4268 .oindex "&%-oMaa%&"
4269 .cindex "authentication" "name, specifying for local message"
4270 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMaa%&
4271 option sets the value of &$sender_host_authenticated$& (the authenticator
4272 name). See chapter &<<CHAPSMTPAUTH>>& for a discussion of SMTP authentication.
4273 This option can be used with &%-bh%& and &%-bs%& to set up an
4274 authenticated SMTP session without actually using the SMTP AUTH command.
4276 .vitem &%-oMai%&&~<&'string'&>
4277 .oindex "&%-oMai%&"
4278 .cindex "authentication" "id, specifying for local message"
4279 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMai%&
4280 option sets the value of &$authenticated_id$& (the id that was authenticated).
4281 This overrides the default value (the caller's login id, except with &%-bh%&,
4282 where there is no default) for messages from local sources. See chapter
4283 &<<CHAPSMTPAUTH>>& for a discussion of authenticated ids.
4285 .vitem &%-oMas%&&~<&'address'&>
4286 .oindex "&%-oMas%&"
4287 .cindex "authentication" "sender, specifying for local message"
4288 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMas%&
4289 option sets the authenticated sender value in &$authenticated_sender$&. It
4290 overrides the sender address that is created from the caller's login id for
4291 messages from local sources, except when &%-bh%& is used, when there is no
4292 default. For both &%-bh%& and &%-bs%&, an authenticated sender that is
4293 specified on a MAIL command overrides this value. See chapter
4294 &<<CHAPSMTPAUTH>>& for a discussion of authenticated senders.
4296 .vitem &%-oMi%&&~<&'interface&~address'&>
4297 .oindex "&%-oMi%&"
4298 .cindex "interface" "address, specifying for local message"
4299 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMi%&
4300 option sets the IP interface address value. A port number may be included,
4301 using the same syntax as for &%-oMa%&. The interface address is placed in
4302 &$received_ip_address$& and the port number, if present, in &$received_port$&.
4304 .vitem &%-oMm%&&~<&'message&~reference'&>
4305 .oindex "&%-oMm%&"
4306 .cindex "message reference" "message reference, specifying for local message"
4307 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMm%&
4308 option sets the message reference, e.g. message-id, and is logged during
4309 delivery. This is useful when some kind of audit trail is required to tie
4310 messages together. The format of the message reference is checked and will
4311 abort if the format is invalid. The option will only be accepted if exim is
4312 running in trusted mode, not as any regular user.
4314 The best example of a message reference is when Exim sends a bounce message.
4315 The message reference is the message-id of the original message for which Exim
4316 is sending the bounce.
4318 .vitem &%-oMr%&&~<&'protocol&~name'&>
4319 .oindex "&%-oMr%&"
4320 .cindex "protocol, specifying for local message"
4321 .vindex "&$received_protocol$&"
4322 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMr%&
4323 option sets the received protocol value that is stored in
4324 &$received_protocol$&. However, it does not apply (and is ignored) when &%-bh%&
4325 or &%-bs%& is used. For &%-bh%&, the protocol is forced to one of the standard
4326 SMTP protocol names (see the description of &$received_protocol$& in section
4327 &<<SECTexpvar>>&). For &%-bs%&, the protocol is always &"local-"& followed by
4328 one of those same names. For &%-bS%& (batched SMTP) however, the protocol can
4329 be set by &%-oMr%&. Repeated use of this option is not supported.
4331 .vitem &%-oMs%&&~<&'host&~name'&>
4332 .oindex "&%-oMs%&"
4333 .cindex "sender" "host name, specifying for local message"
4334 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMs%&
4335 option sets the sender host name in &$sender_host_name$&. When this option is
4336 present, Exim does not attempt to look up a host name from an IP address; it
4337 uses the name it is given.
4339 .vitem &%-oMt%&&~<&'ident&~string'&>
4340 .oindex "&%-oMt%&"
4341 .cindex "sender" "ident string, specifying for local message"
4342 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMt%&
4343 option sets the sender ident value in &$sender_ident$&. The default setting for
4344 local callers is the login id of the calling process, except when &%-bh%& is
4345 used, when there is no default.
4347 .vitem &%-om%&
4348 .oindex "&%-om%&"
4349 .cindex "Sendmail compatibility" "&%-om%& option ignored"
4350 In Sendmail, this option means &"me too"&, indicating that the sender of a
4351 message should receive a copy of the message if the sender appears in an alias
4352 expansion. Exim always does this, so the option does nothing.
4354 .vitem &%-oo%&
4355 .oindex "&%-oo%&"
4356 .cindex "Sendmail compatibility" "&%-oo%& option ignored"
4357 This option is ignored. In Sendmail it specifies &"old style headers"&,
4358 whatever that means.
4360 .vitem &%-oP%&&~<&'path'&>
4361 .oindex "&%-oP%&"
4362 .cindex "pid (process id)" "of daemon"
4363 .cindex "daemon" "process id (pid)"
4364 This option is useful only in conjunction with &%-bd%& or &%-q%& with a time
4365 value. The option specifies the file to which the process id of the daemon is
4366 written. When &%-oX%& is used with &%-bd%&, or when &%-q%& with a time is used
4367 without &%-bd%&, this is the only way of causing Exim to write a pid file,
4368 because in those cases, the normal pid file is not used.
4370 .vitem &%-or%&&~<&'time'&>
4371 .oindex "&%-or%&"
4372 .cindex "timeout" "for non-SMTP input"
4373 This option sets a timeout value for incoming non-SMTP messages. If it is not
4374 set, Exim will wait forever for the standard input. The value can also be set
4375 by the &%receive_timeout%& option. The format used for specifying times is
4376 described in section &<<SECTtimeformat>>&.
4378 .vitem &%-os%&&~<&'time'&>
4379 .oindex "&%-os%&"
4380 .cindex "timeout" "for SMTP input"
4381 .cindex "SMTP" "input timeout"
4382 This option sets a timeout value for incoming SMTP messages. The timeout
4383 applies to each SMTP command and block of data. The value can also be set by
4384 the &%smtp_receive_timeout%& option; it defaults to 5 minutes. The format used
4385 for specifying times is described in section &<<SECTtimeformat>>&.
4387 .vitem &%-ov%&
4388 .oindex "&%-ov%&"
4389 This option has exactly the same effect as &%-v%&.
4391 .vitem &%-oX%&&~<&'number&~or&~string'&>
4392 .oindex "&%-oX%&"
4393 .cindex "TCP/IP" "setting listening ports"
4394 .cindex "TCP/IP" "setting listening interfaces"
4395 .cindex "port" "receiving TCP/IP"
4396 This option is relevant only when the &%-bd%& (start listening daemon) option
4397 is also given. It controls which ports and interfaces the daemon uses. Details
4398 of the syntax, and how it interacts with configuration file options, are given
4399 in chapter &<<CHAPinterfaces>>&. When &%-oX%& is used to start a daemon, no pid
4400 file is written unless &%-oP%& is also present to specify a pid filename.
4402 .vitem &%-pd%&
4403 .oindex "&%-pd%&"
4404 .cindex "Perl" "starting the interpreter"
4405 This option applies when an embedded Perl interpreter is linked with Exim (see
4406 chapter &<<CHAPperl>>&). It overrides the setting of the &%perl_at_start%&
4407 option, forcing the starting of the interpreter to be delayed until it is
4408 needed.
4410 .vitem &%-ps%&
4411 .oindex "&%-ps%&"
4412 .cindex "Perl" "starting the interpreter"
4413 This option applies when an embedded Perl interpreter is linked with Exim (see
4414 chapter &<<CHAPperl>>&). It overrides the setting of the &%perl_at_start%&
4415 option, forcing the starting of the interpreter to occur as soon as Exim is
4416 started.
4418 .vitem &%-p%&<&'rval'&>:<&'sval'&>
4419 .oindex "&%-p%&"
4420 For compatibility with Sendmail, this option is equivalent to
4421 .display
4422 &`-oMr`& <&'rval'&> &`-oMs`& <&'sval'&>
4423 .endd
4424 It sets the incoming protocol and host name (for trusted callers). The
4425 host name and its colon can be omitted when only the protocol is to be set.
4426 Note the Exim already has two private options, &%-pd%& and &%-ps%&, that refer
4427 to embedded Perl. It is therefore impossible to set a protocol value of &`d`&
4428 or &`s`& using this option (but that does not seem a real limitation).
4429 Repeated use of this option is not supported.
4431 .vitem &%-q%&
4432 .oindex "&%-q%&"
4433 .cindex "queue runner" "starting manually"
4434 This option is normally restricted to admin users. However, there is a
4435 configuration option called &%prod_requires_admin%& which can be set false to
4436 relax this restriction (and also the same requirement for the &%-M%&, &%-R%&,
4437 and &%-S%& options).
4439 .cindex "queue runner" "description of operation"
4440 If other commandline options do not specify an action,
4441 the &%-q%& option starts one queue runner process. This scans the queue of
4442 waiting messages, and runs a delivery process for each one in turn. It waits
4443 for each delivery process to finish before starting the next one. A delivery
4444 process may not actually do any deliveries if the retry times for the addresses
4445 have not been reached. Use &%-qf%& (see below) if you want to override this.
4447 If
4448 .cindex "SMTP" "passed connection"
4449 .cindex "SMTP" "multiple deliveries"
4450 .cindex "multiple SMTP deliveries"
4451 the delivery process spawns other processes to deliver other messages down
4452 passed SMTP connections, the queue runner waits for these to finish before
4453 proceeding.
4455 When all the queued messages have been considered, the original queue runner
4456 process terminates. In other words, a single pass is made over the waiting
4457 mail, one message at a time. Use &%-q%& with a time (see below) if you want
4458 this to be repeated periodically.
4460 Exim processes the waiting messages in an unpredictable order. It isn't very
4461 random, but it is likely to be different each time, which is all that matters.
4462 If one particular message screws up a remote MTA, other messages to the same
4463 MTA have a chance of getting through if they get tried first.
4465 It is possible to cause the messages to be processed in lexical message id
4466 order, which is essentially the order in which they arrived, by setting the
4467 &%queue_run_in_order%& option, but this is not recommended for normal use.
4469 .vitem &%-q%&<&'qflags'&>
4470 The &%-q%& option may be followed by one or more flag letters that change its
4471 behaviour. They are all optional, but if more than one is present, they must
4472 appear in the correct order. Each flag is described in a separate item below.
4474 .vitem &%-qq...%&
4475 .oindex "&%-qq%&"
4476 .cindex "queue" "double scanning"
4477 .cindex "queue" "routing"
4478 .cindex "routing" "whole queue before delivery"
4479 An option starting with &%-qq%& requests a two-stage queue run. In the first
4480 stage, the queue is scanned as if the &%queue_smtp_domains%& option matched
4481 every domain. Addresses are routed, local deliveries happen, but no remote
4482 transports are run.
4484 .cindex "hints database" "remembering routing"
4485 The hints database that remembers which messages are waiting for specific hosts
4486 is updated, as if delivery to those hosts had been deferred. After this is
4487 complete, a second, normal queue scan happens, with routing and delivery taking
4488 place as normal. Messages that are routed to the same host should mostly be
4489 delivered down a single SMTP
4490 .cindex "SMTP" "passed connection"
4491 .cindex "SMTP" "multiple deliveries"
4492 .cindex "multiple SMTP deliveries"
4493 connection because of the hints that were set up during the first queue scan.
4494 This option may be useful for hosts that are connected to the Internet
4495 intermittently.
4497 .vitem &%-q[q]i...%&
4498 .oindex "&%-qi%&"
4499 .cindex "queue" "initial delivery"
4500 If the &'i'& flag is present, the queue runner runs delivery processes only for
4501 those messages that haven't previously been tried. (&'i'& stands for &"initial
4502 delivery"&.) This can be helpful if you are putting messages in the queue using
4503 &%-odq%& and want a queue runner just to process the new messages.
4505 .vitem &%-q[q][i]f...%&
4506 .oindex "&%-qf%&"
4507 .cindex "queue" "forcing delivery"
4508 .cindex "delivery" "forcing in queue run"
4509 If one &'f'& flag is present, a delivery attempt is forced for each non-frozen
4510 message, whereas without &'f'& only those non-frozen addresses that have passed
4511 their retry times are tried.
4513 .vitem &%-q[q][i]ff...%&
4514 .oindex "&%-qff%&"
4515 .cindex "frozen messages" "forcing delivery"
4516 If &'ff'& is present, a delivery attempt is forced for every message, whether
4517 frozen or not.
4519 .vitem &%-q[q][i][f[f]]l%&
4520 .oindex "&%-ql%&"
4521 .cindex "queue" "local deliveries only"
4522 The &'l'& (the letter &"ell"&) flag specifies that only local deliveries are to
4523 be done. If a message requires any remote deliveries, it remains in the queue
4524 for later delivery.
4526 .vitem &%-q[q][i][f[f]][l][G<name>[/<time>]]]%&
4527 .oindex "&%-qG%&"
4528 .cindex queue named
4529 .cindex "named queues"
4530 .cindex "queue" "delivering specific messages"
4531 If the &'G'& flag and a name is present, the queue runner operates on the
4532 queue with the given name rather than the default queue.
4533 The name should not contain a &'/'& character.
4534 For a periodic queue run (see below)
4535 append to the name a slash and a time value.
4537 If other commandline options specify an action, a &'-qG<name>'& option
4538 will specify a queue to operate on.
4539 For example:
4540 .code
4541 exim -bp -qGquarantine
4542 mailq -qGquarantine
4543 exim -qGoffpeak -Rf @special.domain.example
4544 .endd
4546 .vitem &%-q%&<&'qflags'&>&~<&'start&~id'&>&~<&'end&~id'&>
4547 When scanning the queue, Exim can be made to skip over messages whose ids are
4548 lexically less than a given value by following the &%-q%& option with a
4549 starting message id. For example:
4550 .code
4551 exim -q 0t5C6f-0000c8-00
4552 .endd
4553 Messages that arrived earlier than &`0t5C6f-0000c8-00`& are not inspected. If a
4554 second message id is given, messages whose ids are lexically greater than it
4555 are also skipped. If the same id is given twice, for example,
4556 .code
4557 exim -q 0t5C6f-0000c8-00 0t5C6f-0000c8-00
4558 .endd
4559 just one delivery process is started, for that message. This differs from
4560 &%-M%& in that retry data is respected, and it also differs from &%-Mc%& in
4561 that it counts as a delivery from a queue run. Note that the selection
4562 mechanism does not affect the order in which the messages are scanned. There
4563 are also other ways of selecting specific sets of messages for delivery in a
4564 queue run &-- see &%-R%& and &%-S%&.
4566 .vitem &%-q%&<&'qflags'&><&'time'&>
4567 .cindex "queue runner" "starting periodically"
4568 .cindex "periodic queue running"
4569 When a time value is present, the &%-q%& option causes Exim to run as a daemon,
4570 starting a queue runner process at intervals specified by the given time value
4571 (whose format is described in section &<<SECTtimeformat>>&). This form of the
4572 &%-q%& option is commonly combined with the &%-bd%& option, in which case a
4573 single daemon process handles both functions. A common way of starting up a
4574 combined daemon at system boot time is to use a command such as
4575 .code
4576 /usr/exim/bin/exim -bd -q30m
4577 .endd
4578 Such a daemon listens for incoming SMTP calls, and also starts a queue runner
4579 process every 30 minutes.
4581 When a daemon is started by &%-q%& with a time value, but without &%-bd%&, no
4582 pid file is written unless one is explicitly requested by the &%-oP%& option.
4584 .vitem &%-qR%&<&'rsflags'&>&~<&'string'&>
4585 .oindex "&%-qR%&"
4586 This option is synonymous with &%-R%&. It is provided for Sendmail
4587 compatibility.
4589 .vitem &%-qS%&<&'rsflags'&>&~<&'string'&>
4590 .oindex "&%-qS%&"
4591 This option is synonymous with &%-S%&.
4593 .vitem &%-R%&<&'rsflags'&>&~<&'string'&>
4594 .oindex "&%-R%&"
4595 .cindex "queue runner" "for specific recipients"
4596 .cindex "delivery" "to given domain"
4597 .cindex "domain" "delivery to"
4598 The <&'rsflags'&> may be empty, in which case the white space before the string
4599 is optional, unless the string is &'f'&, &'ff'&, &'r'&, &'rf'&, or &'rff'&,
4600 which are the possible values for <&'rsflags'&>. White space is required if
4601 <&'rsflags'&> is not empty.
4603 This option is similar to &%-q%& with no time value, that is, it causes Exim to
4604 perform a single queue run, except that, when scanning the messages on the
4605 queue, Exim processes only those that have at least one undelivered recipient
4606 address containing the given string, which is checked in a case-independent
4607 way. If the <&'rsflags'&> start with &'r'&, <&'string'&> is interpreted as a
4608 regular expression; otherwise it is a literal string.
4610 If you want to do periodic queue runs for messages with specific recipients,
4611 you can combine &%-R%& with &%-q%& and a time value. For example:
4612 .code
4613 exim -q25m -R @special.domain.example
4614 .endd
4615 This example does a queue run for messages with recipients in the given domain
4616 every 25 minutes. Any additional flags that are specified with &%-q%& are
4617 applied to each queue run.
4619 Once a message is selected for delivery by this mechanism, all its addresses
4620 are processed. For the first selected message, Exim overrides any retry
4621 information and forces a delivery attempt for each undelivered address. This
4622 means that if delivery of any address in the first message is successful, any
4623 existing retry information is deleted, and so delivery attempts for that
4624 address in subsequently selected messages (which are processed without forcing)
4625 will run. However, if delivery of any address does not succeed, the retry
4626 information is updated, and in subsequently selected messages, the failing
4627 address will be skipped.
4629 .cindex "frozen messages" "forcing delivery"
4630 If the <&'rsflags'&> contain &'f'& or &'ff'&, the delivery forcing applies to
4631 all selected messages, not just the first; frozen messages are included when
4632 &'ff'& is present.
4634 The &%-R%& option makes it straightforward to initiate delivery of all messages
4635 to a given domain after a host has been down for some time. When the SMTP
4636 command ETRN is accepted by its ACL (see chapter &<<CHAPACL>>&), its default
4637 effect is to run Exim with the &%-R%& option, but it can be configured to run
4638 an arbitrary command instead.
4640 .vitem &%-r%&
4641 .oindex "&%-r%&"
4642 This is a documented (for Sendmail) obsolete alternative name for &%-f%&.
4644 .vitem &%-S%&<&'rsflags'&>&~<&'string'&>
4645 .oindex "&%-S%&"
4646 .cindex "delivery" "from given sender"
4647 .cindex "queue runner" "for specific senders"
4648 This option acts like &%-R%& except that it checks the string against each
4649 message's sender instead of against the recipients. If &%-R%& is also set, both
4650 conditions must be met for a message to be selected. If either of the options
4651 has &'f'& or &'ff'& in its flags, the associated action is taken.
4653 .vitem &%-Tqt%&&~<&'times'&>
4654 .oindex "&%-Tqt%&"
4655 This is an option that is exclusively for use by the Exim testing suite. It is not
4656 recognized when Exim is run normally. It allows for the setting up of explicit
4657 &"queue times"& so that various warning/retry features can be tested.
4659 .vitem &%-t%&
4660 .oindex "&%-t%&"
4661 .cindex "recipient" "extracting from header lines"
4662 .cindex "&'Bcc:'& header line"
4663 .cindex "&'Cc:'& header line"
4664 .cindex "&'To:'& header line"
4665 When Exim is receiving a locally-generated, non-SMTP message on its standard
4666 input, the &%-t%& option causes the recipients of the message to be obtained
4667 from the &'To:'&, &'Cc:'&, and &'Bcc:'& header lines in the message instead of
4668 from the command arguments. The addresses are extracted before any rewriting
4669 takes place and the &'Bcc:'& header line, if present, is then removed.
4671 .cindex "Sendmail compatibility" "&%-t%& option"
4672 If the command has any arguments, they specify addresses to which the message
4673 is &'not'& to be delivered. That is, the argument addresses are removed from
4674 the recipients list obtained from the headers. This is compatible with Smail 3
4675 and in accordance with the documented behaviour of several versions of
4676 Sendmail, as described in man pages on a number of operating systems (e.g.
4677 Solaris 8, IRIX 6.5, HP-UX 11). However, some versions of Sendmail &'add'&
4678 argument addresses to those obtained from the headers, and the O'Reilly
4679 Sendmail book documents it that way. Exim can be made to add argument addresses
4680 instead of subtracting them by setting the option
4681 &%extract_addresses_remove_arguments%& false.
4683 .cindex "&%Resent-%& header lines" "with &%-t%&"
4684 If there are any &%Resent-%& header lines in the message, Exim extracts
4685 recipients from all &'Resent-To:'&, &'Resent-Cc:'&, and &'Resent-Bcc:'& header
4686 lines instead of from &'To:'&, &'Cc:'&, and &'Bcc:'&. This is for compatibility
4687 with Sendmail and other MTAs. (Prior to release 4.20, Exim gave an error if
4688 &%-t%& was used in conjunction with &%Resent-%& header lines.)
4690 RFC 2822 talks about different sets of &%Resent-%& header lines (for when a
4691 message is resent several times). The RFC also specifies that they should be
4692 added at the front of the message, and separated by &'Received:'& lines. It is
4693 not at all clear how &%-t%& should operate in the present of multiple sets,
4694 nor indeed exactly what constitutes a &"set"&.
4695 In practice, it seems that MUAs do not follow the RFC. The &%Resent-%& lines
4696 are often added at the end of the header, and if a message is resent more than
4697 once, it is common for the original set of &%Resent-%& headers to be renamed as
4698 &%X-Resent-%& when a new set is added. This removes any possible ambiguity.
4700 .vitem &%-ti%&
4701 .oindex "&%-ti%&"
4702 This option is exactly equivalent to &%-t%& &%-i%&. It is provided for
4703 compatibility with Sendmail.
4705 .vitem &%-tls-on-connect%&
4706 .oindex "&%-tls-on-connect%&"
4707 .cindex "TLS" "use without STARTTLS"
4708 .cindex "TLS" "automatic start"
4709 This option is available when Exim is compiled with TLS support. It forces all
4710 incoming SMTP connections to behave as if the incoming port is listed in the
4711 &%tls_on_connect_ports%& option. See section &<<SECTsupobssmt>>& and chapter
4712 &<<CHAPTLS>>& for further details.
4715 .vitem &%-U%&
4716 .oindex "&%-U%&"
4717 .cindex "Sendmail compatibility" "&%-U%& option ignored"
4718 Sendmail uses this option for &"initial message submission"&, and its
4719 documentation states that in future releases, it may complain about
4720 syntactically invalid messages rather than fixing them when this flag is not
4721 set. Exim ignores this option.
4723 .vitem &%-v%&
4724 .oindex "&%-v%&"
4725 This option causes Exim to write information to the standard error stream,
4726 describing what it is doing. In particular, it shows the log lines for
4727 receiving and delivering a message, and if an SMTP connection is made, the SMTP
4728 dialogue is shown. Some of the log lines shown may not actually be written to
4729 the log if the setting of &%log_selector%& discards them. Any relevant
4730 selectors are shown with each log line. If none are shown, the logging is
4731 unconditional.
4733 .vitem &%-x%&
4734 .oindex "&%-x%&"
4735 AIX uses &%-x%& for a private purpose (&"mail from a local mail program has
4736 National Language Support extended characters in the body of the mail item"&).
4737 It sets &%-x%& when calling the MTA from its &%mail%& command. Exim ignores
4738 this option.
4740 .vitem &%-X%&&~<&'logfile'&>
4741 .oindex "&%-X%&"
4742 This option is interpreted by Sendmail to cause debug information to be sent
4743 to the named file. It is ignored by Exim.
4745 .vitem &%-z%&&~<&'log-line'&>
4746 .oindex "&%-z%&"
4747 This option writes its argument to Exim's logfile.
4748 Use is restricted to administrators; the intent is for operational notes.
4749 Quotes should be used to maintain a multi-word item as a single argument,
4750 under most shells.
4751 .endlist
4753 .ecindex IIDclo1
4754 .ecindex IIDclo2
4757 . ////////////////////////////////////////////////////////////////////////////
4758 . Insert a stylized DocBook comment here, to identify the end of the command
4759 . line options. This is for the benefit of the Perl script that automatically
4760 . creates a man page for the options.
4761 . ////////////////////////////////////////////////////////////////////////////
4763 .literal xml
4764 <!-- === End of command line options === -->
4765 .literal off
4771 . ////////////////////////////////////////////////////////////////////////////
4772 . ////////////////////////////////////////////////////////////////////////////
4775 .chapter "The Exim runtime configuration file" "CHAPconf" &&&
4776 "The runtime configuration file"
4778 .cindex "runtime configuration"
4779 .cindex "configuration file" "general description"
4780 .cindex "CONFIGURE_FILE"
4781 .cindex "configuration file" "errors in"
4782 .cindex "error" "in configuration file"
4783 .cindex "return code" "for bad configuration"
4784 Exim uses a single runtime configuration file that is read whenever an Exim
4785 binary is executed. Note that in normal operation, this happens frequently,
4786 because Exim is designed to operate in a distributed manner, without central
4787 control.
4789 If a syntax error is detected while reading the configuration file, Exim
4790 writes a message on the standard error, and exits with a non-zero return code.
4791 The message is also written to the panic log. &*Note*&: Only simple syntax
4792 errors can be detected at this time. The values of any expanded options are
4793 not checked until the expansion happens, even when the expansion does not
4794 actually alter the string.
4796 The name of the configuration file is compiled into the binary for security
4797 reasons, and is specified by the CONFIGURE_FILE compilation option. In
4798 most configurations, this specifies a single file. However, it is permitted to
4799 give a colon-separated list of filenames, in which case Exim uses the first
4800 existing file in the list.
4802 .cindex "EXIM_USER"
4803 .cindex "EXIM_GROUP"
4804 .cindex "CONFIGURE_OWNER"
4805 .cindex "CONFIGURE_GROUP"
4806 .cindex "configuration file" "ownership"
4807 .cindex "ownership" "configuration file"
4808 The runtime configuration file must be owned by root or by the user that is
4809 specified at compile time by the CONFIGURE_OWNER option (if set). The
4810 configuration file must not be world-writeable, or group-writeable unless its
4811 group is the root group or the one specified at compile time by the