Spec docs for IDNA2008 support
[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 printing 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 generate the outermost <book> element that wraps then 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 "4.88"
49 .include ./local_params
51 .set ACL "access control lists (ACLs)"
52 .set I "&nbsp;&nbsp;&nbsp;&nbsp;"
54 .macro copyyear
55 2017
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 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 . --- the 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 the program,
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 the 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, the 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(http://www.uit.co.uk/exim-book/)).
395 This 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 the program 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 the program (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 and web sites" "SECID2"
447 .cindex "web site"
448 .cindex "FTP site"
449 The primary site for Exim source distributions is currently the University of
450 Cambridge's FTP site, whose contents are described in &'Where to find the Exim
451 distribution'& below. In addition, there is a web site and an FTP site at
452 &%exim.org%&. These are now also hosted at the University of Cambridge. The
453 &%exim.org%& site was previously hosted for a number of years by Energis
454 Squared, formerly Planet Online Ltd, whose support I gratefully acknowledge.
456 .cindex "wiki"
457 .cindex "FAQ"
458 As well as Exim distribution tar files, the Exim web site contains a number of
459 differently formatted versions of the documentation. A recent addition to the
460 online information is the Exim wiki (&url(http://wiki.exim.org)),
461 which contains what used to be a separate FAQ, as well as various other
462 examples, tips, and know-how that have been contributed by Exim users.
464 .cindex Bugzilla
465 An Exim Bugzilla exists at &url(http://bugs.exim.org). You can use
466 this to report bugs, and also to add items to the wish list. Please search
467 first to check that you are not duplicating a previous entry.
471 .section "Mailing lists" "SECID3"
472 .cindex "mailing lists" "for Exim users"
473 The following Exim mailing lists exist:
475 .table2 140pt
476 .row &'exim-announce@exim.org'& "Moderated, low volume announcements list"
477 .row &'exim-users@exim.org'& "General discussion list"
478 .row &'exim-dev@exim.org'& "Discussion of bugs, enhancements, etc."
479 .row &'exim-cvs@exim.org'& "Automated commit messages from the VCS"
480 .endtable
482 You can subscribe to these lists, change your existing subscriptions, and view
483 or search the archives via the mailing lists link on the Exim home page.
484 .cindex "Debian" "mailing list for"
485 If you are using a Debian distribution of Exim, you may wish to subscribe to
486 the Debian-specific mailing list &'pkg-exim4-users@lists.alioth.debian.org'&
487 via this web page:
488 .display
489 &url(http://lists.alioth.debian.org/mailman/listinfo/pkg-exim4-users)
490 .endd
491 Please ask Debian-specific questions on this list and not on the general Exim
492 lists.
494 .section "Exim training" "SECID4"
495 .cindex "training courses"
496 Training courses in Cambridge (UK) used to be run annually by the author of
497 Exim, before he retired. At the time of writing, there are no plans to run
498 further Exim courses in Cambridge. However, if that changes, relevant
499 information will be posted at &url(http://www-tus.csx.cam.ac.uk/courses/exim/).
501 .section "Bug reports" "SECID5"
502 .cindex "bug reports"
503 .cindex "reporting bugs"
504 Reports of obvious bugs can be emailed to &'bugs@exim.org'& or reported
505 via the Bugzilla (&url(http://bugs.exim.org)). However, if you are unsure
506 whether some behaviour is a bug or not, the best thing to do is to post a
507 message to the &'exim-dev'& mailing list and have it discussed.
511 .section "Where to find the Exim distribution" "SECTavail"
512 .cindex "FTP site"
513 .cindex "distribution" "ftp site"
514 The master ftp site for the Exim distribution is
515 .display
516 &*ftp://ftp.csx.cam.ac.uk/pub/software/email/exim*&
517 .endd
518 This is mirrored by
519 .display
520 &*ftp://ftp.exim.org/pub/exim*&
521 .endd
522 The file references that follow are relative to the &_exim_& directories at
523 these sites. There are now quite a number of independent mirror sites around
524 the world. Those that I know about are listed in the file called &_Mirrors_&.
526 Within the &_exim_& directory there are subdirectories called &_exim3_& (for
527 previous Exim 3 distributions), &_exim4_& (for the latest Exim 4
528 distributions), and &_Testing_& for testing versions. In the &_exim4_&
529 subdirectory, the current release can always be found in files called
530 .display
531 &_exim-n.nn.tar.gz_&
532 &_exim-n.nn.tar.bz2_&
533 .endd
534 where &'n.nn'& is the highest such version number in the directory. The two
535 files contain identical data; the only difference is the type of compression.
536 The &_.bz2_& file is usually a lot smaller than the &_.gz_& file.
538 .cindex "distribution" "signing details"
539 .cindex "distribution" "public key"
540 .cindex "public key for signed distribution"
541 The distributions will be PGP signed by an individual key of the Release
542 Coordinator. This key will have a uid containing an email address in the
543 &'exim.org'& domain and will have signatures from other people, including
544 other Exim maintainers. We expect that the key will be in the "strong set" of
545 PGP keys. There should be a trust path to that key from Nigel Metheringham's
546 PGP key, a version of which can be found in the release directory in the file
547 &_nigel-pubkey.asc_&. All keys used will be available in public keyserver pools,
548 such as &'pool.sks-keyservers.net'&.
550 At time of last update, releases were being made by Phil Pennock and signed with
551 key &'0x403043153903637F'&, although that key is expected to be replaced in 2013.
552 A trust path from Nigel's key to Phil's can be observed at
553 &url(https://www.security.spodhuis.org/exim-trustpath).
555 Releases have also been authorized to be performed by Todd Lyons who signs with
556 key &'0xC4F4F94804D29EBA'&. A direct trust path exists between previous RE Phil
557 Pennock and Todd Lyons through a common associate.
559 The signatures for the tar bundles are in:
560 .display
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 separately 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_& as well as &_.gz_& 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 "Run time configuration" "SECID7"
623 Exim's run time 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 on 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 on 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 that
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 on 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(http://www.pobox.com/~djb/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(http://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 licence 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 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 file names, 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 so-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 address
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 any 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 the program 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. Run time options specify which
1196 ones are actually used for delivering messages.
1198 .cindex "drivers" "instance definition"
1199 Each driver that is specified in the run time 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 specially by the local host. These
1235 are typically 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 as case-sensitive. 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 The &%local_part_prefix%& and &%local_part_suffix%& options can specify that
1366 the local parts handled by the router may or must have certain prefixes and/or
1367 suffixes. If a mandatory affix (prefix or suffix) is not present, the router is
1368 skipped. These conditions are tested first. When an affix is present, it is
1369 removed from the local part before further processing, including the evaluation
1370 of any other conditions.
1371 .next
1372 Routers can be designated for use only when not verifying an address, that is,
1373 only when routing it for delivery (or testing its delivery routing). If the
1374 &%verify%& option is set false, the router is skipped when Exim is verifying an
1375 address.
1376 Setting the &%verify%& option actually sets two options, &%verify_sender%& and
1377 &%verify_recipient%&, which independently control the use of the router for
1378 sender and recipient verification. You can set these options directly if
1379 you want a router to be used for only one type of verification.
1380 Note that cutthrough delivery is classed as a recipient verification for this purpose.
1381 .next
1382 If the &%address_test%& option is set false, the router is skipped when Exim is
1383 run with the &%-bt%& option to test an address routing. This can be helpful
1384 when the first router sends all new messages to a scanner of some sort; it
1385 makes it possible to use &%-bt%& to test subsequent delivery routing without
1386 having to simulate the effect of the scanner.
1387 .next
1388 Routers can be designated for use only when verifying an address, as
1389 opposed to routing it for delivery. The &%verify_only%& option controls this.
1390 Again, cutthrough delivery counts as a verification.
1391 .next
1392 Individual routers can be explicitly skipped when running the routers to
1393 check an address given in the SMTP EXPN command (see the &%expn%& option).
1394 .next
1395 If the &%domains%& option is set, the domain of the address must be in the set
1396 of domains that it defines.
1397 .next
1398 .vindex "&$local_part_prefix$&"
1399 .vindex "&$local_part$&"
1400 .vindex "&$local_part_suffix$&"
1401 If the &%local_parts%& option is set, the local part of the address must be in
1402 the set of local parts that it defines. If &%local_part_prefix%& or
1403 &%local_part_suffix%& is in use, the prefix or suffix is removed from the local
1404 part before this check. If you want to do precondition tests on local parts
1405 that include affixes, you can do so by using a &%condition%& option (see below)
1406 that uses the variables &$local_part$&, &$local_part_prefix$&, and
1407 &$local_part_suffix$& as necessary.
1408 .next
1409 .vindex "&$local_user_uid$&"
1410 .vindex "&$local_user_gid$&"
1411 .vindex "&$home$&"
1412 If the &%check_local_user%& option is set, the local part must be the name of
1413 an account on the local host. If this check succeeds, the uid and gid of the
1414 local user are placed in &$local_user_uid$& and &$local_user_gid$& and the
1415 user's home directory is placed in &$home$&; these values can be used in the
1416 remaining preconditions.
1417 .next
1418 If the &%router_home_directory%& option is set, it is expanded at this point,
1419 because it overrides the value of &$home$&. If this expansion were left till
1420 later, the value of &$home$& as set by &%check_local_user%& would be used in
1421 subsequent tests. Having two different values of &$home$& in the same router
1422 could lead to confusion.
1423 .next
1424 If the &%senders%& option is set, the envelope sender address must be in the
1425 set of addresses that it defines.
1426 .next
1427 If the &%require_files%& option is set, the existence or non-existence of
1428 specified files is tested.
1429 .next
1430 .cindex "customizing" "precondition"
1431 If the &%condition%& option is set, it is evaluated and tested. This option
1432 uses an expanded string to allow you to set up your own custom preconditions.
1433 Expanded strings are described in chapter &<<CHAPexpand>>&.
1434 .endlist
1437 Note that &%require_files%& comes near the end of the list, so you cannot use
1438 it to check for the existence of a file in which to lookup up a domain, local
1439 part, or sender. However, as these options are all expanded, you can use the
1440 &%exists%& expansion condition to make such tests within each condition. The
1441 &%require_files%& option is intended for checking files that the router may be
1442 going to use internally, or which are needed by a specific transport (for
1443 example, &_.procmailrc_&).
1447 .section "Delivery in detail" "SECID18"
1448 .cindex "delivery" "in detail"
1449 When a message is to be delivered, the sequence of events is as follows:
1451 .ilist
1452 If a system-wide filter file is specified, the message is passed to it. The
1453 filter may add recipients to the message, replace the recipients, discard the
1454 message, cause a new message to be generated, or cause the message delivery to
1455 fail. The format of the system filter file is the same as for Exim user filter
1456 files, described in the separate document entitled &'Exim's interfaces to mail
1457 filtering'&.
1458 .cindex "Sieve filter" "not available for system filter"
1459 (&*Note*&: Sieve cannot be used for system filter files.)
1461 Some additional features are available in system filters &-- see chapter
1462 &<<CHAPsystemfilter>>& for details. Note that a message is passed to the system
1463 filter only once per delivery attempt, however many recipients it has. However,
1464 if there are several delivery attempts because one or more addresses could not
1465 be immediately delivered, the system filter is run each time. The filter
1466 condition &%first_delivery%& can be used to detect the first run of the system
1467 filter.
1468 .next
1469 Each recipient address is offered to each configured router in turn, subject to
1470 its preconditions, until one is able to handle it. If no router can handle the
1471 address, that is, if they all decline, the address is failed. Because routers
1472 can be targeted at particular domains, several locally handled domains can be
1473 processed entirely independently of each other.
1474 .next
1475 .cindex "routing" "loops in"
1476 .cindex "loop" "while routing"
1477 A router that accepts an address may assign it to a local or a remote
1478 transport. However, the transport is not run at this time. Instead, the address
1479 is placed on a list for the particular transport, which will be run later.
1480 Alternatively, the router may generate one or more new addresses (typically
1481 from alias, forward, or filter files). New addresses are fed back into this
1482 process from the top, but in order to avoid loops, a router ignores any address
1483 which has an identically-named ancestor that was processed by itself.
1484 .next
1485 When all the routing has been done, addresses that have been successfully
1486 handled are passed to their assigned transports. When local transports are
1487 doing real local deliveries, they handle only one address at a time, but if a
1488 local transport is being used as a pseudo-remote transport (for example, to
1489 collect batched SMTP messages for transmission by some other means) multiple
1490 addresses can be handled. Remote transports can always handle more than one
1491 address at a time, but can be configured not to do so, or to restrict multiple
1492 addresses to the same domain.
1493 .next
1494 Each local delivery to a file or a pipe runs in a separate process under a
1495 non-privileged uid, and these deliveries are run one at a time. Remote
1496 deliveries also run in separate processes, normally under a uid that is private
1497 to Exim (&"the Exim user"&), but in this case, several remote deliveries can be
1498 run in parallel. The maximum number of simultaneous remote deliveries for any
1499 one message is set by the &%remote_max_parallel%& option.
1500 The order in which deliveries are done is not defined, except that all local
1501 deliveries happen before any remote deliveries.
1502 .next
1503 .cindex "queue runner"
1504 When it encounters a local delivery during a queue run, Exim checks its retry
1505 database to see if there has been a previous temporary delivery failure for the
1506 address before running the local transport. If there was a previous failure,
1507 Exim does not attempt a new delivery until the retry time for the address is
1508 reached. However, this happens only for delivery attempts that are part of a
1509 queue run. Local deliveries are always attempted when delivery immediately
1510 follows message reception, even if retry times are set for them. This makes for
1511 better behaviour if one particular message is causing problems (for example,
1512 causing quota overflow, or provoking an error in a filter file).
1513 .next
1514 .cindex "delivery" "retry in remote transports"
1515 Remote transports do their own retry handling, since an address may be
1516 deliverable to one of a number of hosts, each of which may have a different
1517 retry time. If there have been previous temporary failures and no host has
1518 reached its retry time, no delivery is attempted, whether in a queue run or
1519 not. See chapter &<<CHAPretry>>& for details of retry strategies.
1520 .next
1521 If there were any permanent errors, a bounce message is returned to an
1522 appropriate address (the sender in the common case), with details of the error
1523 for each failing address. Exim can be configured to send copies of bounce
1524 messages to other addresses.
1525 .next
1526 .cindex "delivery" "deferral"
1527 If one or more addresses suffered a temporary failure, the message is left on
1528 the queue, to be tried again later. Delivery of these addresses is said to be
1529 &'deferred'&.
1530 .next
1531 When all the recipient addresses have either been delivered or bounced,
1532 handling of the message is complete. The spool files and message log are
1533 deleted, though the message log can optionally be preserved if required.
1534 .endlist
1539 .section "Retry mechanism" "SECID19"
1540 .cindex "delivery" "retry mechanism"
1541 .cindex "retry" "description of mechanism"
1542 .cindex "queue runner"
1543 Exim's mechanism for retrying messages that fail to get delivered at the first
1544 attempt is the queue runner process. You must either run an Exim daemon that
1545 uses the &%-q%& option with a time interval to start queue runners at regular
1546 intervals, or use some other means (such as &'cron'&) to start them. If you do
1547 not arrange for queue runners to be run, messages that fail temporarily at the
1548 first attempt will remain on your queue for ever. A queue runner process works
1549 its way through the queue, one message at a time, trying each delivery that has
1550 passed its retry time.
1551 You can run several queue runners at once.
1553 Exim uses a set of configured rules to determine when next to retry the failing
1554 address (see chapter &<<CHAPretry>>&). These rules also specify when Exim
1555 should give up trying to deliver to the address, at which point it generates a
1556 bounce message. If no retry rules are set for a particular host, address, and
1557 error combination, no retries are attempted, and temporary errors are treated
1558 as permanent.
1562 .section "Temporary delivery failure" "SECID20"
1563 .cindex "delivery" "temporary failure"
1564 There are many reasons why a message may not be immediately deliverable to a
1565 particular address. Failure to connect to a remote machine (because it, or the
1566 connection to it, is down) is one of the most common. Temporary failures may be
1567 detected during routing as well as during the transport stage of delivery.
1568 Local deliveries may be delayed if NFS files are unavailable, or if a mailbox
1569 is on a file system where the user is over quota. Exim can be configured to
1570 impose its own quotas on local mailboxes; where system quotas are set they will
1571 also apply.
1573 If a host is unreachable for a period of time, a number of messages may be
1574 waiting for it by the time it recovers, and sending them in a single SMTP
1575 connection is clearly beneficial. Whenever a delivery to a remote host is
1576 deferred,
1577 .cindex "hints database" "deferred deliveries"
1578 Exim makes a note in its hints database, and whenever a successful
1579 SMTP delivery has happened, it looks to see if any other messages are waiting
1580 for the same host. If any are found, they are sent over the same SMTP
1581 connection, subject to a configuration limit as to the maximum number in any
1582 one connection.
1586 .section "Permanent delivery failure" "SECID21"
1587 .cindex "delivery" "permanent failure"
1588 .cindex "bounce message" "when generated"
1589 When a message cannot be delivered to some or all of its intended recipients, a
1590 bounce message is generated. Temporary delivery failures turn into permanent
1591 errors when their timeout expires. All the addresses that fail in a given
1592 delivery attempt are listed in a single message. If the original message has
1593 many recipients, it is possible for some addresses to fail in one delivery
1594 attempt and others to fail subsequently, giving rise to more than one bounce
1595 message. The wording of bounce messages can be customized by the administrator.
1596 See chapter &<<CHAPemsgcust>>& for details.
1598 .cindex "&'X-Failed-Recipients:'& header line"
1599 Bounce messages contain an &'X-Failed-Recipients:'& header line that lists the
1600 failed addresses, for the benefit of programs that try to analyse such messages
1601 automatically.
1603 .cindex "bounce message" "recipient of"
1604 A bounce message is normally sent to the sender of the original message, as
1605 obtained from the message's envelope. For incoming SMTP messages, this is the
1606 address given in the MAIL command. However, when an address is expanded via a
1607 forward or alias file, an alternative address can be specified for delivery
1608 failures of the generated addresses. For a mailing list expansion (see section
1609 &<<SECTmailinglists>>&) it is common to direct bounce messages to the manager
1610 of the list.
1614 .section "Failures to deliver bounce messages" "SECID22"
1615 .cindex "bounce message" "failure to deliver"
1616 If a bounce message (either locally generated or received from a remote host)
1617 itself suffers a permanent delivery failure, the message is left on the queue,
1618 but it is frozen, awaiting the attention of an administrator. There are options
1619 that can be used to make Exim discard such failed messages, or to keep them
1620 for only a short time (see &%timeout_frozen_after%& and
1621 &%ignore_bounce_errors_after%&).
1627 . ////////////////////////////////////////////////////////////////////////////
1628 . ////////////////////////////////////////////////////////////////////////////
1630 .chapter "Building and installing Exim" "CHID3"
1631 .scindex IIDbuex "building Exim"
1633 .section "Unpacking" "SECID23"
1634 Exim is distributed as a gzipped or bzipped tar file which, when unpacked,
1635 creates a directory with the name of the current release (for example,
1636 &_exim-&version()_&) into which the following files are placed:
1638 .table2 140pt
1639 .irow &_ACKNOWLEDGMENTS_& "contains some acknowledgments"
1640 .irow &_CHANGES_& "contains a reference to where changes are &&&
1641 documented"
1642 .irow &_LICENCE_& "the GNU General Public Licence"
1643 .irow &_Makefile_& "top-level make file"
1644 .irow &_NOTICE_& "conditions for the use of Exim"
1645 .irow &_README_& "list of files, directories and simple build &&&
1646 instructions"
1647 .endtable
1649 Other files whose names begin with &_README_& may also be present. The
1650 following subdirectories are created:
1652 .table2 140pt
1653 .irow &_Local_& "an empty directory for local configuration files"
1654 .irow &_OS_& "OS-specific files"
1655 .irow &_doc_& "documentation files"
1656 .irow &_exim_monitor_& "source files for the Exim monitor"
1657 .irow &_scripts_& "scripts used in the build process"
1658 .irow &_src_& "remaining source files"
1659 .irow &_util_& "independent utilities"
1660 .endtable
1662 The main utility programs are contained in the &_src_& directory, and are built
1663 with the Exim binary. The &_util_& directory contains a few optional scripts
1664 that may be useful to some sites.
1667 .section "Multiple machine architectures and operating systems" "SECID24"
1668 .cindex "building Exim" "multiple OS/architectures"
1669 The building process for Exim is arranged to make it easy to build binaries for
1670 a number of different architectures and operating systems from the same set of
1671 source files. Compilation does not take place in the &_src_& directory.
1672 Instead, a &'build directory'& is created for each architecture and operating
1673 system.
1674 .cindex "symbolic link" "to build directory"
1675 Symbolic links to the sources are installed in this directory, which is where
1676 the actual building takes place. In most cases, Exim can discover the machine
1677 architecture and operating system for itself, but the defaults can be
1678 overridden if necessary.
1681 .section "PCRE library" "SECTpcre"
1682 .cindex "PCRE library"
1683 Exim no longer has an embedded PCRE library as the vast majority of
1684 modern systems include PCRE as a system library, although you may need
1685 to install the PCRE or PCRE development package for your operating
1686 system. If your system has a normal PCRE installation the Exim build
1687 process will need no further configuration. If the library or the
1688 headers are in an unusual location you will need to either set the PCRE_LIBS
1689 and INCLUDE directives appropriately,
1690 or set PCRE_CONFIG=yes to use the installed &(pcre-config)& command.
1691 If your operating system has no
1692 PCRE support then you will need to obtain and build the current PCRE
1693 from &url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/).
1694 More information on PCRE is available at &url(http://www.pcre.org/).
1696 .section "DBM libraries" "SECTdb"
1697 .cindex "DBM libraries" "discussion of"
1698 .cindex "hints database" "DBM files used for"
1699 Even if you do not use any DBM files in your configuration, Exim still needs a
1700 DBM library in order to operate, because it uses indexed files for its hints
1701 databases. Unfortunately, there are a number of DBM libraries in existence, and
1702 different operating systems often have different ones installed.
1704 .cindex "Solaris" "DBM library for"
1705 .cindex "IRIX, DBM library for"
1706 .cindex "BSD, DBM library for"
1707 .cindex "Linux, DBM library for"
1708 If you are using Solaris, IRIX, one of the modern BSD systems, or a modern
1709 Linux distribution, the DBM configuration should happen automatically, and you
1710 may be able to ignore this section. Otherwise, you may have to learn more than
1711 you would like about DBM libraries from what follows.
1713 .cindex "&'ndbm'& DBM library"
1714 Licensed versions of Unix normally contain a library of DBM functions operating
1715 via the &'ndbm'& interface, and this is what Exim expects by default. Free
1716 versions of Unix seem to vary in what they contain as standard. In particular,
1717 some early versions of Linux have no default DBM library, and different
1718 distributors have chosen to bundle different libraries with their packaged
1719 versions. However, the more recent releases seem to have standardized on the
1720 Berkeley DB library.
1722 Different DBM libraries have different conventions for naming the files they
1723 use. When a program opens a file called &_dbmfile_&, there are several
1724 possibilities:
1726 .olist
1727 A traditional &'ndbm'& implementation, such as that supplied as part of
1728 Solaris, operates on two files called &_dbmfile.dir_& and &_dbmfile.pag_&.
1729 .next
1730 .cindex "&'gdbm'& DBM library"
1731 The GNU library, &'gdbm'&, operates on a single file. If used via its &'ndbm'&
1732 compatibility interface it makes two different hard links to it with names
1733 &_dbmfile.dir_& and &_dbmfile.pag_&, but if used via its native interface, the
1734 file name is used unmodified.
1735 .next
1736 .cindex "Berkeley DB library"
1737 The Berkeley DB package, if called via its &'ndbm'& compatibility interface,
1738 operates on a single file called &_dbmfile.db_&, but otherwise looks to the
1739 programmer exactly the same as the traditional &'ndbm'& implementation.
1740 .next
1741 If the Berkeley package is used in its native mode, it operates on a single
1742 file called &_dbmfile_&; the programmer's interface is somewhat different to
1743 the traditional &'ndbm'& interface.
1744 .next
1745 To complicate things further, there are several very different versions of the
1746 Berkeley DB package. Version 1.85 was stable for a very long time, releases
1747 2.&'x'& and 3.&'x'& were current for a while, but the latest versions are now
1748 numbered 4.&'x'&. Maintenance of some of the earlier releases has ceased. All
1749 versions of Berkeley DB can be obtained from
1750 &url(http://www.sleepycat.com/).
1751 .next
1752 .cindex "&'tdb'& DBM library"
1753 Yet another DBM library, called &'tdb'&, is available from
1754 &url(http://download.sourceforge.net/tdb). It has its own interface, and also
1755 operates on a single file.
1756 .endlist
1758 .cindex "USE_DB"
1759 .cindex "DBM libraries" "configuration for building"
1760 Exim and its utilities can be compiled to use any of these interfaces. In order
1761 to use any version of the Berkeley DB package in native mode, you must set
1762 USE_DB in an appropriate configuration file (typically
1763 &_Local/Makefile_&). For example:
1764 .code
1765 USE_DB=yes
1766 .endd
1767 Similarly, for gdbm you set USE_GDBM, and for tdb you set USE_TDB. An
1768 error is diagnosed if you set more than one of these.
1770 At the lowest level, the build-time configuration sets none of these options,
1771 thereby assuming an interface of type (1). However, some operating system
1772 configuration files (for example, those for the BSD operating systems and
1773 Linux) assume type (4) by setting USE_DB as their default, and the
1774 configuration files for Cygwin set USE_GDBM. Anything you set in
1775 &_Local/Makefile_&, however, overrides these system defaults.
1777 As well as setting USE_DB, USE_GDBM, or USE_TDB, it may also be
1778 necessary to set DBMLIB, to cause inclusion of the appropriate library, as
1779 in one of these lines:
1780 .code
1781 DBMLIB = -ldb
1782 DBMLIB = -ltdb
1783 .endd
1784 Settings like that will work if the DBM library is installed in the standard
1785 place. Sometimes it is not, and the library's header file may also not be in
1786 the default path. You may need to set INCLUDE to specify where the header
1787 file is, and to specify the path to the library more fully in DBMLIB, as in
1788 this example:
1789 .code
1790 INCLUDE=-I/usr/local/include/db-4.1
1791 DBMLIB=/usr/local/lib/db-4.1/libdb.a
1792 .endd
1793 There is further detailed discussion about the various DBM libraries in the
1794 file &_doc/dbm.discuss.txt_& in the Exim distribution.
1798 .section "Pre-building configuration" "SECID25"
1799 .cindex "building Exim" "pre-building configuration"
1800 .cindex "configuration for building Exim"
1801 .cindex "&_Local/Makefile_&"
1802 .cindex "&_src/EDITME_&"
1803 Before building Exim, a local configuration file that specifies options
1804 independent of any operating system has to be created with the name
1805 &_Local/Makefile_&. A template for this file is supplied as the file
1806 &_src/EDITME_&, and it contains full descriptions of all the option settings
1807 therein. These descriptions are therefore not repeated here. If you are
1808 building Exim for the first time, the simplest thing to do is to copy
1809 &_src/EDITME_& to &_Local/Makefile_&, then read it and edit it appropriately.
1811 There are three settings that you must supply, because Exim will not build
1812 without them. They are the location of the run time configuration file
1813 (CONFIGURE_FILE), the directory in which Exim binaries will be installed
1814 (BIN_DIRECTORY), and the identity of the Exim user (EXIM_USER and
1815 maybe EXIM_GROUP as well). The value of CONFIGURE_FILE can in fact be
1816 a colon-separated list of file names; Exim uses the first of them that exists.
1818 There are a few other parameters that can be specified either at build time or
1819 at run time, to enable the same binary to be used on a number of different
1820 machines. However, if the locations of Exim's spool directory and log file
1821 directory (if not within the spool directory) are fixed, it is recommended that
1822 you specify them in &_Local/Makefile_& instead of at run time, so that errors
1823 detected early in Exim's execution (such as a malformed configuration file) can
1824 be logged.
1826 .cindex "content scanning" "specifying at build time"
1827 Exim's interfaces for calling virus and spam scanning software directly from
1828 access control lists are not compiled by default. If you want to include these
1829 facilities, you need to set
1830 .code
1832 .endd
1833 in your &_Local/Makefile_&. For details of the facilities themselves, see
1834 chapter &<<CHAPexiscan>>&.
1837 .cindex "&_Local/eximon.conf_&"
1838 .cindex "&_exim_monitor/EDITME_&"
1839 If you are going to build the Exim monitor, a similar configuration process is
1840 required. The file &_exim_monitor/EDITME_& must be edited appropriately for
1841 your installation and saved under the name &_Local/eximon.conf_&. If you are
1842 happy with the default settings described in &_exim_monitor/EDITME_&,
1843 &_Local/eximon.conf_& can be empty, but it must exist.
1845 This is all the configuration that is needed in straightforward cases for known
1846 operating systems. However, the building process is set up so that it is easy
1847 to override options that are set by default or by operating-system-specific
1848 configuration files, for example to change the name of the C compiler, which
1849 defaults to &%gcc%&. See section &<<SECToverride>>& below for details of how to
1850 do this.
1854 .section "Support for iconv()" "SECID26"
1855 .cindex "&[iconv()]& support"
1856 .cindex "RFC 2047"
1857 The contents of header lines in messages may be encoded according to the rules
1858 described RFC 2047. This makes it possible to transmit characters that are not
1859 in the ASCII character set, and to label them as being in a particular
1860 character set. When Exim is inspecting header lines by means of the &%$h_%&
1861 mechanism, it decodes them, and translates them into a specified character set
1862 (default is set at build time). The translation is possible only if the operating system
1863 supports the &[iconv()]& function.
1865 However, some of the operating systems that supply &[iconv()]& do not support
1866 very many conversions. The GNU &%libiconv%& library (available from
1867 &url(http://www.gnu.org/software/libiconv/)) can be installed on such
1868 systems to remedy this deficiency, as well as on systems that do not supply
1869 &[iconv()]& at all. After installing &%libiconv%&, you should add
1870 .code
1871 HAVE_ICONV=yes
1872 .endd
1873 to your &_Local/Makefile_& and rebuild Exim.
1877 .section "Including TLS/SSL encryption support" "SECTinctlsssl"
1878 .cindex "TLS" "including support for TLS"
1879 .cindex "encryption" "including support for"
1880 .cindex "SUPPORT_TLS"
1881 .cindex "OpenSSL" "building Exim with"
1882 .cindex "GnuTLS" "building Exim with"
1883 Exim can be built to support encrypted SMTP connections, using the STARTTLS
1884 command as per RFC 2487. It can also support legacy clients that expect to
1885 start a TLS session immediately on connection to a non-standard port (see the
1886 &%tls_on_connect_ports%& runtime option and the &%-tls-on-connect%& command
1887 line option).
1889 If you want to build Exim with TLS support, you must first install either the
1890 OpenSSL or GnuTLS library. There is no cryptographic code in Exim itself for
1891 implementing SSL.
1893 If OpenSSL is installed, you should set
1894 .code
1895 SUPPORT_TLS=yes
1896 TLS_LIBS=-lssl -lcrypto
1897 .endd
1898 in &_Local/Makefile_&. You may also need to specify the locations of the
1899 OpenSSL library and include files. For example:
1900 .code
1901 SUPPORT_TLS=yes
1902 TLS_LIBS=-L/usr/local/openssl/lib -lssl -lcrypto
1903 TLS_INCLUDE=-I/usr/local/openssl/include/
1904 .endd
1905 .cindex "pkg-config" "OpenSSL"
1906 If you have &'pkg-config'& available, then instead you can just use:
1907 .code
1908 SUPPORT_TLS=yes
1909 USE_OPENSSL_PC=openssl
1910 .endd
1911 .cindex "USE_GNUTLS"
1912 If GnuTLS is installed, you should set
1913 .code
1914 SUPPORT_TLS=yes
1915 USE_GNUTLS=yes
1916 TLS_LIBS=-lgnutls -ltasn1 -lgcrypt
1917 .endd
1918 in &_Local/Makefile_&, and again you may need to specify the locations of the
1919 library and include files. For example:
1920 .code
1921 SUPPORT_TLS=yes
1922 USE_GNUTLS=yes
1923 TLS_LIBS=-L/usr/gnu/lib -lgnutls -ltasn1 -lgcrypt
1924 TLS_INCLUDE=-I/usr/gnu/include
1925 .endd
1926 .cindex "pkg-config" "GnuTLS"
1927 If you have &'pkg-config'& available, then instead you can just use:
1928 .code
1929 SUPPORT_TLS=yes
1930 USE_GNUTLS=yes
1931 USE_GNUTLS_PC=gnutls
1932 .endd
1934 You do not need to set TLS_INCLUDE if the relevant directory is already
1935 specified in INCLUDE. Details of how to configure Exim to make use of TLS are
1936 given in chapter &<<CHAPTLS>>&.
1941 .section "Use of tcpwrappers" "SECID27"
1943 .cindex "tcpwrappers, building Exim to support"
1944 .cindex "USE_TCP_WRAPPERS"
1946 .cindex "tcp_wrappers_daemon_name"
1947 Exim can be linked with the &'tcpwrappers'& library in order to check incoming
1948 SMTP calls using the &'tcpwrappers'& control files. This may be a convenient
1949 alternative to Exim's own checking facilities for installations that are
1950 already making use of &'tcpwrappers'& for other purposes. To do this, you
1951 should set USE_TCP_WRAPPERS in &_Local/Makefile_&, arrange for the file
1952 &_tcpd.h_& to be available at compile time, and also ensure that the library
1953 &_libwrap.a_& is available at link time, typically by including &%-lwrap%& in
1954 EXTRALIBS_EXIM. For example, if &'tcpwrappers'& is installed in &_/usr/local_&,
1955 you might have
1956 .code
1958 CFLAGS=-O -I/usr/local/include
1959 EXTRALIBS_EXIM=-L/usr/local/lib -lwrap
1960 .endd
1961 in &_Local/Makefile_&. The daemon name to use in the &'tcpwrappers'& control
1962 files is &"exim"&. For example, the line
1963 .code
1964 exim : LOCAL 192.168.1. .friendly.domain.example
1965 .endd
1966 in your &_/etc/hosts.allow_& file allows connections from the local host, from
1967 the subnet, and from all hosts in &'friendly.domain.example'&.
1968 All other connections are denied. The daemon name used by &'tcpwrappers'&
1969 can be changed at build time by setting TCP_WRAPPERS_DAEMON_NAME in
1970 &_Local/Makefile_&, or by setting tcp_wrappers_daemon_name in the
1971 configure file. Consult the &'tcpwrappers'& documentation for
1972 further details.
1975 .section "Including support for IPv6" "SECID28"
1976 .cindex "IPv6" "including support for"
1977 Exim contains code for use on systems that have IPv6 support. Setting
1978 &`HAVE_IPV6=YES`& in &_Local/Makefile_& causes the IPv6 code to be included;
1979 it may also be necessary to set IPV6_INCLUDE and IPV6_LIBS on systems
1980 where the IPv6 support is not fully integrated into the normal include and
1981 library files.
1983 Two different types of DNS record for handling IPv6 addresses have been
1984 defined. AAAA records (analogous to A records for IPv4) are in use, and are
1985 currently seen as the mainstream. Another record type called A6 was proposed
1986 as better than AAAA because it had more flexibility. However, it was felt to be
1987 over-complex, and its status was reduced to &"experimental"&.
1988 Exim used to
1989 have a compile option for including A6 record support but this has now been
1990 withdrawn.
1994 .section "Dynamically loaded lookup module support" "SECTdynamicmodules"
1995 .cindex "lookup modules"
1996 .cindex "dynamic modules"
1997 .cindex ".so building"
1998 On some platforms, Exim supports not compiling all lookup types directly into
1999 the main binary, instead putting some into external modules which can be loaded
2000 on demand.
2001 This permits packagers to build Exim with support for lookups with extensive
2002 library dependencies without requiring all users to install all of those
2003 dependencies.
2004 Most, but not all, lookup types can be built this way.
2006 Set &`LOOKUP_MODULE_DIR`& to the directory into which the modules will be
2007 installed; Exim will only load modules from that directory, as a security
2008 measure. You will need to set &`CFLAGS_DYNAMIC`& if not already defined
2009 for your OS; see &_OS/Makefile-Linux_& for an example.
2010 Some other requirements for adjusting &`EXTRALIBS`& may also be necessary,
2011 see &_src/EDITME_& for details.
2013 Then, for each module to be loaded dynamically, define the relevant
2014 &`LOOKUP_`&<&'lookup_type'&> flags to have the value "2" instead of "yes".
2015 For example, this will build in lsearch but load sqlite and mysql support
2016 on demand:
2017 .code
2021 .endd
2024 .section "The building process" "SECID29"
2025 .cindex "build directory"
2026 Once &_Local/Makefile_& (and &_Local/eximon.conf_&, if required) have been
2027 created, run &'make'& at the top level. It determines the architecture and
2028 operating system types, and creates a build directory if one does not exist.
2029 For example, on a Sun system running Solaris 8, the directory
2030 &_build-SunOS5-5.8-sparc_& is created.
2031 .cindex "symbolic link" "to source files"
2032 Symbolic links to relevant source files are installed in the build directory.
2034 If this is the first time &'make'& has been run, it calls a script that builds
2035 a make file inside the build directory, using the configuration files from the
2036 &_Local_& directory. The new make file is then passed to another instance of
2037 &'make'&. This does the real work, building a number of utility scripts, and
2038 then compiling and linking the binaries for the Exim monitor (if configured), a
2039 number of utility programs, and finally Exim itself. The command &`make
2040 makefile`& can be used to force a rebuild of the make file in the build
2041 directory, should this ever be necessary.
2043 If you have problems building Exim, check for any comments there may be in the
2044 &_README_& file concerning your operating system, and also take a look at the
2045 FAQ, where some common problems are covered.
2049 .section 'Output from &"make"&' "SECID283"
2050 The output produced by the &'make'& process for compile lines is often very
2051 unreadable, because these lines can be very long. For this reason, the normal
2052 output is suppressed by default, and instead output similar to that which
2053 appears when compiling the 2.6 Linux kernel is generated: just a short line for
2054 each module that is being compiled or linked. However, it is still possible to
2055 get the full output, by calling &'make'& like this:
2056 .code
2057 FULLECHO='' make -e
2058 .endd
2059 The value of FULLECHO defaults to &"@"&, the flag character that suppresses
2060 command reflection in &'make'&. When you ask for the full output, it is
2061 given in addition to the short output.
2065 .section "Overriding build-time options for Exim" "SECToverride"
2066 .cindex "build-time options, overriding"
2067 The main make file that is created at the beginning of the building process
2068 consists of the concatenation of a number of files which set configuration
2069 values, followed by a fixed set of &'make'& instructions. If a value is set
2070 more than once, the last setting overrides any previous ones. This provides a
2071 convenient way of overriding defaults. The files that are concatenated are, in
2072 order:
2073 .display
2074 &_OS/Makefile-Default_&
2075 &_OS/Makefile-_&<&'ostype'&>
2076 &_Local/Makefile_&
2077 &_Local/Makefile-_&<&'ostype'&>
2078 &_Local/Makefile-_&<&'archtype'&>
2079 &_Local/Makefile-_&<&'ostype'&>-<&'archtype'&>
2080 &_OS/Makefile-Base_&
2081 .endd
2082 .cindex "&_Local/Makefile_&"
2083 .cindex "building Exim" "operating system type"
2084 .cindex "building Exim" "architecture type"
2085 where <&'ostype'&> is the operating system type and <&'archtype'&> is the
2086 architecture type. &_Local/Makefile_& is required to exist, and the building
2087 process fails if it is absent. The other three &_Local_& files are optional,
2088 and are often not needed.
2090 The values used for <&'ostype'&> and <&'archtype'&> are obtained from scripts
2091 called &_scripts/os-type_& and &_scripts/arch-type_& respectively. If either of
2092 the environment variables EXIM_OSTYPE or EXIM_ARCHTYPE is set, their
2093 values are used, thereby providing a means of forcing particular settings.
2094 Otherwise, the scripts try to get values from the &%uname%& command. If this
2095 fails, the shell variables OSTYPE and ARCHTYPE are inspected. A number
2096 of &'ad hoc'& transformations are then applied, to produce the standard names
2097 that Exim expects. You can run these scripts directly from the shell in order
2098 to find out what values are being used on your system.
2101 &_OS/Makefile-Default_& contains comments about the variables that are set
2102 therein. Some (but not all) are mentioned below. If there is something that
2103 needs changing, review the contents of this file and the contents of the make
2104 file for your operating system (&_OS/Makefile-<ostype>_&) to see what the
2105 default values are.
2108 .cindex "building Exim" "overriding default settings"
2109 If you need to change any of the values that are set in &_OS/Makefile-Default_&
2110 or in &_OS/Makefile-<ostype>_&, or to add any new definitions, you do not
2111 need to change the original files. Instead, you should make the changes by
2112 putting the new values in an appropriate &_Local_& file. For example,
2113 .cindex "Tru64-Unix build-time settings"
2114 when building Exim in many releases of the Tru64-Unix (formerly Digital UNIX,
2115 formerly DEC-OSF1) operating system, it is necessary to specify that the C
2116 compiler is called &'cc'& rather than &'gcc'&. Also, the compiler must be
2117 called with the option &%-std1%&, to make it recognize some of the features of
2118 Standard C that Exim uses. (Most other compilers recognize Standard C by
2119 default.) To do this, you should create a file called &_Local/Makefile-OSF1_&
2120 containing the lines
2121 .code
2122 CC=cc
2123 CFLAGS=-std1
2124 .endd
2125 If you are compiling for just one operating system, it may be easier to put
2126 these lines directly into &_Local/Makefile_&.
2128 Keeping all your local configuration settings separate from the distributed
2129 files makes it easy to transfer them to new versions of Exim simply by copying
2130 the contents of the &_Local_& directory.
2133 .cindex "NIS lookup type" "including support for"
2134 .cindex "NIS+ lookup type" "including support for"
2135 .cindex "LDAP" "including support for"
2136 .cindex "lookup" "inclusion in binary"
2137 Exim contains support for doing LDAP, NIS, NIS+, and other kinds of file
2138 lookup, but not all systems have these components installed, so the default is
2139 not to include the relevant code in the binary. All the different kinds of file
2140 and database lookup that Exim supports are implemented as separate code modules
2141 which are included only if the relevant compile-time options are set. In the
2142 case of LDAP, NIS, and NIS+, the settings for &_Local/Makefile_& are:
2143 .code
2144 LOOKUP_LDAP=yes
2145 LOOKUP_NIS=yes
2147 .endd
2148 and similar settings apply to the other lookup types. They are all listed in
2149 &_src/EDITME_&. In many cases the relevant include files and interface
2150 libraries need to be installed before compiling Exim.
2151 .cindex "cdb" "including support for"
2152 However, there are some optional lookup types (such as cdb) for which
2153 the code is entirely contained within Exim, and no external include
2154 files or libraries are required. When a lookup type is not included in the
2155 binary, attempts to configure Exim to use it cause run time configuration
2156 errors.
2158 .cindex "pkg-config" "lookups"
2159 .cindex "pkg-config" "authenticators"
2160 Many systems now use a tool called &'pkg-config'& to encapsulate information
2161 about how to compile against a library; Exim has some initial support for
2162 being able to use pkg-config for lookups and authenticators. For any given
2163 makefile variable which starts &`LOOKUP_`& or &`AUTH_`&, you can add a new
2164 variable with the &`_PC`& suffix in the name and assign as the value the
2165 name of the package to be queried. The results of querying via the
2166 &'pkg-config'& command will be added to the appropriate Makefile variables
2167 with &`+=`& directives, so your version of &'make'& will need to support that
2168 syntax. For instance:
2169 .code
2171 LOOKUP_SQLITE_PC=sqlite3
2172 AUTH_GSASL=yes
2173 AUTH_GSASL_PC=libgsasl
2175 AUTH_HEIMDAL_GSSAPI_PC=heimdal-gssapi
2176 .endd
2178 .cindex "Perl" "including support for"
2179 Exim can be linked with an embedded Perl interpreter, allowing Perl
2180 subroutines to be called during string expansion. To enable this facility,
2181 .code
2182 EXIM_PERL=perl.o
2183 .endd
2184 must be defined in &_Local/Makefile_&. Details of this facility are given in
2185 chapter &<<CHAPperl>>&.
2187 .cindex "X11 libraries, location of"
2188 The location of the X11 libraries is something that varies a lot between
2189 operating systems, and there may be different versions of X11 to cope
2190 with. Exim itself makes no use of X11, but if you are compiling the Exim
2191 monitor, the X11 libraries must be available.
2192 The following three variables are set in &_OS/Makefile-Default_&:
2193 .code
2194 X11=/usr/X11R6
2195 XINCLUDE=-I$(X11)/include
2196 XLFLAGS=-L$(X11)/lib
2197 .endd
2198 These are overridden in some of the operating-system configuration files. For
2199 example, in &_OS/Makefile-SunOS5_& there is
2200 .code
2201 X11=/usr/openwin
2202 XINCLUDE=-I$(X11)/include
2203 XLFLAGS=-L$(X11)/lib -R$(X11)/lib
2204 .endd
2205 If you need to override the default setting for your operating system, place a
2206 definition of all three of these variables into your
2207 &_Local/Makefile-<ostype>_& file.
2209 .cindex "EXTRALIBS"
2210 If you need to add any extra libraries to the link steps, these can be put in a
2211 variable called EXTRALIBS, which appears in all the link commands, but by
2212 default is not defined. In contrast, EXTRALIBS_EXIM is used only on the
2213 command for linking the main Exim binary, and not for any associated utilities.
2215 .cindex "DBM libraries" "configuration for building"
2216 There is also DBMLIB, which appears in the link commands for binaries that
2217 use DBM functions (see also section &<<SECTdb>>&). Finally, there is
2218 EXTRALIBS_EXIMON, which appears only in the link step for the Exim monitor
2219 binary, and which can be used, for example, to include additional X11
2220 libraries.
2222 .cindex "configuration file" "editing"
2223 The make file copes with rebuilding Exim correctly if any of the configuration
2224 files are edited. However, if an optional configuration file is deleted, it is
2225 necessary to touch the associated non-optional file (that is,
2226 &_Local/Makefile_& or &_Local/eximon.conf_&) before rebuilding.
2229 .section "OS-specific header files" "SECID30"
2230 .cindex "&_os.h_&"
2231 .cindex "building Exim" "OS-specific C header files"
2232 The &_OS_& directory contains a number of files with names of the form
2233 &_os.h-<ostype>_&. These are system-specific C header files that should not
2234 normally need to be changed. There is a list of macro settings that are
2235 recognized in the file &_OS/os.configuring_&, which should be consulted if you
2236 are porting Exim to a new operating system.
2240 .section "Overriding build-time options for the monitor" "SECID31"
2241 .cindex "building Eximon"
2242 A similar process is used for overriding things when building the Exim monitor,
2243 where the files that are involved are
2244 .display
2245 &_OS/eximon.conf-Default_&
2246 &_OS/eximon.conf-_&<&'ostype'&>
2247 &_Local/eximon.conf_&
2248 &_Local/eximon.conf-_&<&'ostype'&>
2249 &_Local/eximon.conf-_&<&'archtype'&>
2250 &_Local/eximon.conf-_&<&'ostype'&>-<&'archtype'&>
2251 .endd
2252 .cindex "&_Local/eximon.conf_&"
2253 As with Exim itself, the final three files need not exist, and in this case the
2254 &_OS/eximon.conf-<ostype>_& file is also optional. The default values in
2255 &_OS/eximon.conf-Default_& can be overridden dynamically by setting environment
2256 variables of the same name, preceded by EXIMON_. For example, setting
2257 EXIMON_LOG_DEPTH in the environment overrides the value of
2258 LOG_DEPTH at run time.
2259 .ecindex IIDbuex
2262 .section "Installing Exim binaries and scripts" "SECID32"
2263 .cindex "installing Exim"
2264 .cindex "BIN_DIRECTORY"
2265 The command &`make install`& runs the &(exim_install)& script with no
2266 arguments. The script copies binaries and utility scripts into the directory
2267 whose name is specified by the BIN_DIRECTORY setting in &_Local/Makefile_&.
2268 .cindex "setuid" "installing Exim with"
2269 The install script copies files only if they are newer than the files they are
2270 going to replace. The Exim binary is required to be owned by root and have the
2271 &'setuid'& bit set, for normal configurations. Therefore, you must run &`make
2272 install`& as root so that it can set up the Exim binary in this way. However, in
2273 some special situations (for example, if a host is doing no local deliveries)
2274 it may be possible to run Exim without making the binary setuid root (see
2275 chapter &<<CHAPsecurity>>& for details).
2277 .cindex "CONFIGURE_FILE"
2278 Exim's run time configuration file is named by the CONFIGURE_FILE setting
2279 in &_Local/Makefile_&. If this names a single file, and the file does not
2280 exist, the default configuration file &_src/configure.default_& is copied there
2281 by the installation script. If a run time configuration file already exists, it
2282 is left alone. If CONFIGURE_FILE is a colon-separated list, naming several
2283 alternative files, no default is installed.
2285 .cindex "system aliases file"
2286 .cindex "&_/etc/aliases_&"
2287 One change is made to the default configuration file when it is installed: the
2288 default configuration contains a router that references a system aliases file.
2289 The path to this file is set to the value specified by
2290 SYSTEM_ALIASES_FILE in &_Local/Makefile_& (&_/etc/aliases_& by default).
2291 If the system aliases file does not exist, the installation script creates it,
2292 and outputs a comment to the user.
2294 The created file contains no aliases, but it does contain comments about the
2295 aliases a site should normally have. Mail aliases have traditionally been
2296 kept in &_/etc/aliases_&. However, some operating systems are now using
2297 &_/etc/mail/aliases_&. You should check if yours is one of these, and change
2298 Exim's configuration if necessary.
2300 The default configuration uses the local host's name as the only local domain,
2301 and is set up to do local deliveries into the shared directory &_/var/mail_&,
2302 running as the local user. System aliases and &_.forward_& files in users' home
2303 directories are supported, but no NIS or NIS+ support is configured. Domains
2304 other than the name of the local host are routed using the DNS, with delivery
2305 over SMTP.
2307 It is possible to install Exim for special purposes (such as building a binary
2308 distribution) in a private part of the file system. You can do this by a
2309 command such as
2310 .code
2311 make DESTDIR=/some/directory/ install
2312 .endd
2313 This has the effect of pre-pending the specified directory to all the file
2314 paths, except the name of the system aliases file that appears in the default
2315 configuration. (If a default alias file is created, its name &'is'& modified.)
2316 For backwards compatibility, ROOT is used if DESTDIR is not set,
2317 but this usage is deprecated.
2319 .cindex "installing Exim" "what is not installed"
2320 Running &'make install'& does not copy the Exim 4 conversion script
2321 &'convert4r4'&. You will probably run this only once if you are
2322 upgrading from Exim 3. None of the documentation files in the &_doc_&
2323 directory are copied, except for the info files when you have set
2324 INFO_DIRECTORY, as described in section &<<SECTinsinfdoc>>& below.
2326 For the utility programs, old versions are renamed by adding the suffix &_.O_&
2327 to their names. The Exim binary itself, however, is handled differently. It is
2328 installed under a name that includes the version number and the compile number,
2329 for example &_exim-&version()-1_&. The script then arranges for a symbolic link
2330 called &_exim_& to point to the binary. If you are updating a previous version
2331 of Exim, the script takes care to ensure that the name &_exim_& is never absent
2332 from the directory (as seen by other processes).
2334 .cindex "installing Exim" "testing the script"
2335 If you want to see what the &'make install'& will do before running it for
2336 real, you can pass the &%-n%& option to the installation script by this
2337 command:
2338 .code
2339 make INSTALL_ARG=-n install
2340 .endd
2341 The contents of the variable INSTALL_ARG are passed to the installation
2342 script. You do not need to be root to run this test. Alternatively, you can run
2343 the installation script directly, but this must be from within the build
2344 directory. For example, from the top-level Exim directory you could use this
2345 command:
2346 .code
2347 (cd build-SunOS5-5.5.1-sparc; ../scripts/exim_install -n)
2348 .endd
2349 .cindex "installing Exim" "install script options"
2350 There are two other options that can be supplied to the installation script.
2352 .ilist
2353 &%-no_chown%& bypasses the call to change the owner of the installed binary
2354 to root, and the call to make it a setuid binary.
2355 .next
2356 &%-no_symlink%& bypasses the setting up of the symbolic link &_exim_& to the
2357 installed binary.
2358 .endlist
2360 INSTALL_ARG can be used to pass these options to the script. For example:
2361 .code
2362 make INSTALL_ARG=-no_symlink install
2363 .endd
2364 The installation script can also be given arguments specifying which files are
2365 to be copied. For example, to install just the Exim binary, and nothing else,
2366 without creating the symbolic link, you could use:
2367 .code
2368 make INSTALL_ARG='-no_symlink exim' install
2369 .endd
2373 .section "Installing info documentation" "SECTinsinfdoc"
2374 .cindex "installing Exim" "&'info'& documentation"
2375 Not all systems use the GNU &'info'& system for documentation, and for this
2376 reason, the Texinfo source of Exim's documentation is not included in the main
2377 distribution. Instead it is available separately from the ftp site (see section
2378 &<<SECTavail>>&).
2380 If you have defined INFO_DIRECTORY in &_Local/Makefile_& and the Texinfo
2381 source of the documentation is found in the source tree, running &`make
2382 install`& automatically builds the info files and installs them.
2386 .section "Setting up the spool directory" "SECID33"
2387 .cindex "spool directory" "creating"
2388 When it starts up, Exim tries to create its spool directory if it does not
2389 exist. The Exim uid and gid are used for the owner and group of the spool
2390 directory. Sub-directories are automatically created in the spool directory as
2391 necessary.
2396 .section "Testing" "SECID34"
2397 .cindex "testing" "installation"
2398 Having installed Exim, you can check that the run time configuration file is
2399 syntactically valid by running the following command, which assumes that the
2400 Exim binary directory is within your PATH environment variable:
2401 .code
2402 exim -bV
2403 .endd
2404 If there are any errors in the configuration file, Exim outputs error messages.
2405 Otherwise it outputs the version number and build date,
2406 the DBM library that is being used, and information about which drivers and
2407 other optional code modules are included in the binary.
2408 Some simple routing tests can be done by using the address testing option. For
2409 example,
2410 .display
2411 &`exim -bt`& <&'local username'&>
2412 .endd
2413 should verify that it recognizes a local mailbox, and
2414 .display
2415 &`exim -bt`& <&'remote address'&>
2416 .endd
2417 a remote one. Then try getting it to deliver mail, both locally and remotely.
2418 This can be done by passing messages directly to Exim, without going through a
2419 user agent. For example:
2420 .code
2421 exim -v postmaster@your.domain.example
2422 From: user@your.domain.example
2423 To: postmaster@your.domain.example
2424 Subject: Testing Exim
2426 This is a test message.
2427 ^D
2428 .endd
2429 The &%-v%& option causes Exim to output some verification of what it is doing.
2430 In this case you should see copies of three log lines, one for the message's
2431 arrival, one for its delivery, and one containing &"Completed"&.
2433 .cindex "delivery" "problems with"
2434 If you encounter problems, look at Exim's log files (&'mainlog'& and
2435 &'paniclog'&) to see if there is any relevant information there. Another source
2436 of information is running Exim with debugging turned on, by specifying the
2437 &%-d%& option. If a message is stuck on Exim's spool, you can force a delivery
2438 with debugging turned on by a command of the form
2439 .display
2440 &`exim -d -M`& <&'exim-message-id'&>
2441 .endd
2442 You must be root or an &"admin user"& in order to do this. The &%-d%& option
2443 produces rather a lot of output, but you can cut this down to specific areas.
2444 For example, if you use &%-d-all+route%& only the debugging information
2445 relevant to routing is included. (See the &%-d%& option in chapter
2446 &<<CHAPcommandline>>& for more details.)
2448 .cindex '&"sticky"& bit'
2449 .cindex "lock files"
2450 One specific problem that has shown up on some sites is the inability to do
2451 local deliveries into a shared mailbox directory, because it does not have the
2452 &"sticky bit"& set on it. By default, Exim tries to create a lock file before
2453 writing to a mailbox file, and if it cannot create the lock file, the delivery
2454 is deferred. You can get round this either by setting the &"sticky bit"& on the
2455 directory, or by setting a specific group for local deliveries and allowing
2456 that group to create files in the directory (see the comments above the
2457 &(local_delivery)& transport in the default configuration file). Another
2458 approach is to configure Exim not to use lock files, but just to rely on
2459 &[fcntl()]& locking instead. However, you should do this only if all user
2460 agents also use &[fcntl()]& locking. For further discussion of locking issues,
2461 see chapter &<<CHAPappendfile>>&.
2463 One thing that cannot be tested on a system that is already running an MTA is
2464 the receipt of incoming SMTP mail on the standard SMTP port. However, the
2465 &%-oX%& option can be used to run an Exim daemon that listens on some other
2466 port, or &'inetd'& can be used to do this. The &%-bh%& option and the
2467 &'exim_checkaccess'& utility can be used to check out policy controls on
2468 incoming SMTP mail.
2470 Testing a new version on a system that is already running Exim can most easily
2471 be done by building a binary with a different CONFIGURE_FILE setting. From
2472 within the run time configuration, all other file and directory names
2473 that Exim uses can be altered, in order to keep it entirely clear of the
2474 production version.
2477 .section "Replacing another MTA with Exim" "SECID35"
2478 .cindex "replacing another MTA"
2479 Building and installing Exim for the first time does not of itself put it in
2480 general use. The name by which the system's MTA is called by mail user agents
2481 is either &_/usr/sbin/sendmail_&, or &_/usr/lib/sendmail_& (depending on the
2482 operating system), and it is necessary to make this name point to the &'exim'&
2483 binary in order to get the user agents to pass messages to Exim. This is
2484 normally done by renaming any existing file and making &_/usr/sbin/sendmail_&
2485 or &_/usr/lib/sendmail_&
2486 .cindex "symbolic link" "to &'exim'& binary"
2487 a symbolic link to the &'exim'& binary. It is a good idea to remove any setuid
2488 privilege and executable status from the old MTA. It is then necessary to stop
2489 and restart the mailer daemon, if one is running.
2491 .cindex "FreeBSD, MTA indirection"
2492 .cindex "&_/etc/mail/mailer.conf_&"
2493 Some operating systems have introduced alternative ways of switching MTAs. For
2494 example, if you are running FreeBSD, you need to edit the file
2495 &_/etc/mail/mailer.conf_& instead of setting up a symbolic link as just
2496 described. A typical example of the contents of this file for running Exim is
2497 as follows:
2498 .code
2499 sendmail /usr/exim/bin/exim
2500 send-mail /usr/exim/bin/exim
2501 mailq /usr/exim/bin/exim -bp
2502 newaliases /usr/bin/true
2503 .endd
2504 Once you have set up the symbolic link, or edited &_/etc/mail/mailer.conf_&,
2505 your Exim installation is &"live"&. Check it by sending a message from your
2506 favourite user agent.
2508 You should consider what to tell your users about the change of MTA. Exim may
2509 have different capabilities to what was previously running, and there are
2510 various operational differences such as the text of messages produced by
2511 command line options and in bounce messages. If you allow your users to make
2512 use of Exim's filtering capabilities, you should make the document entitled
2513 &'Exim's interface to mail filtering'& available to them.
2517 .section "Upgrading Exim" "SECID36"
2518 .cindex "upgrading Exim"
2519 If you are already running Exim on your host, building and installing a new
2520 version automatically makes it available to MUAs, or any other programs that
2521 call the MTA directly. However, if you are running an Exim daemon, you do need
2522 to send it a HUP signal, to make it re-execute itself, and thereby pick up the
2523 new binary. You do not need to stop processing mail in order to install a new
2524 version of Exim. The install script does not modify an existing runtime
2525 configuration file.
2530 .section "Stopping the Exim daemon on Solaris" "SECID37"
2531 .cindex "Solaris" "stopping Exim on"
2532 The standard command for stopping the mailer daemon on Solaris is
2533 .code
2534 /etc/init.d/sendmail stop
2535 .endd
2536 If &_/usr/lib/sendmail_& has been turned into a symbolic link, this script
2537 fails to stop Exim because it uses the command &'ps -e'& and greps the output
2538 for the text &"sendmail"&; this is not present because the actual program name
2539 (that is, &"exim"&) is given by the &'ps'& command with these options. A
2540 solution is to replace the line that finds the process id with something like
2541 .code
2542 pid=`cat /var/spool/exim/exim-daemon.pid`
2543 .endd
2544 to obtain the daemon's pid directly from the file that Exim saves it in.
2546 Note, however, that stopping the daemon does not &"stop Exim"&. Messages can
2547 still be received from local processes, and if automatic delivery is configured
2548 (the normal case), deliveries will still occur.
2553 . ////////////////////////////////////////////////////////////////////////////
2554 . ////////////////////////////////////////////////////////////////////////////
2556 .chapter "The Exim command line" "CHAPcommandline"
2557 .scindex IIDclo1 "command line" "options"
2558 .scindex IIDclo2 "options" "command line"
2559 Exim's command line takes the standard Unix form of a sequence of options,
2560 each starting with a hyphen character, followed by a number of arguments. The
2561 options are compatible with the main options of Sendmail, and there are also
2562 some additional options, some of which are compatible with Smail 3. Certain
2563 combinations of options do not make sense, and provoke an error if used.
2564 The form of the arguments depends on which options are set.
2567 .section "Setting options by program name" "SECID38"
2568 .cindex "&'mailq'&"
2569 If Exim is called under the name &'mailq'&, it behaves as if the option &%-bp%&
2570 were present before any other options.
2571 The &%-bp%& option requests a listing of the contents of the mail queue on the
2572 standard output.
2573 This feature is for compatibility with some systems that contain a command of
2574 that name in one of the standard libraries, symbolically linked to
2575 &_/usr/sbin/sendmail_& or &_/usr/lib/sendmail_&.
2577 .cindex "&'rsmtp'&"
2578 If Exim is called under the name &'rsmtp'& it behaves as if the option &%-bS%&
2579 were present before any other options, for compatibility with Smail. The
2580 &%-bS%& option is used for reading in a number of messages in batched SMTP
2581 format.
2583 .cindex "&'rmail'&"
2584 If Exim is called under the name &'rmail'& it behaves as if the &%-i%& and
2585 &%-oee%& options were present before any other options, for compatibility with
2586 Smail. The name &'rmail'& is used as an interface by some UUCP systems.
2588 .cindex "&'runq'&"
2589 .cindex "queue runner"
2590 If Exim is called under the name &'runq'& it behaves as if the option &%-q%&
2591 were present before any other options, for compatibility with Smail. The &%-q%&
2592 option causes a single queue runner process to be started.
2594 .cindex "&'newaliases'&"
2595 .cindex "alias file" "building"
2596 .cindex "Sendmail compatibility" "calling Exim as &'newaliases'&"
2597 If Exim is called under the name &'newaliases'& it behaves as if the option
2598 &%-bi%& were present before any other options, for compatibility with Sendmail.
2599 This option is used for rebuilding Sendmail's alias file. Exim does not have
2600 the concept of a single alias file, but can be configured to run a given
2601 command if called with the &%-bi%& option.
2604 .section "Trusted and admin users" "SECTtrustedadmin"
2605 Some Exim options are available only to &'trusted users'& and others are
2606 available only to &'admin users'&. In the description below, the phrases &"Exim
2607 user"& and &"Exim group"& mean the user and group defined by EXIM_USER and
2608 EXIM_GROUP in &_Local/Makefile_& or set by the &%exim_user%& and
2609 &%exim_group%& options. These do not necessarily have to use the name &"exim"&.
2611 .ilist
2612 .cindex "trusted users" "definition of"
2613 .cindex "user" "trusted definition of"
2614 The trusted users are root, the Exim user, any user listed in the
2615 &%trusted_users%& configuration option, and any user whose current group or any
2616 supplementary group is one of those listed in the &%trusted_groups%&
2617 configuration option. Note that the Exim group is not automatically trusted.
2619 .cindex '&"From"& line'
2620 .cindex "envelope sender"
2621 Trusted users are always permitted to use the &%-f%& option or a leading
2622 &"From&~"& line to specify the envelope sender of a message that is passed to
2623 Exim through the local interface (see the &%-bm%& and &%-f%& options below).
2624 See the &%untrusted_set_sender%& option for a way of permitting non-trusted
2625 users to set envelope senders.
2627 .cindex "&'From:'& header line"
2628 .cindex "&'Sender:'& header line"
2629 .cindex "header lines" "From:"
2630 .cindex "header lines" "Sender:"
2631 For a trusted user, there is never any check on the contents of the &'From:'&
2632 header line, and a &'Sender:'& line is never added. Furthermore, any existing
2633 &'Sender:'& line in incoming local (non-TCP/IP) messages is not removed.
2635 Trusted users may also specify a host name, host address, interface address,
2636 protocol name, ident value, and authentication data when submitting a message
2637 locally. Thus, they are able to insert messages into Exim's queue locally that
2638 have the characteristics of messages received from a remote host. Untrusted
2639 users may in some circumstances use &%-f%&, but can never set the other values
2640 that are available to trusted users.
2641 .next
2642 .cindex "user" "admin definition of"
2643 .cindex "admin user" "definition of"
2644 The admin users are root, the Exim user, and any user that is a member of the
2645 Exim group or of any group listed in the &%admin_groups%& configuration option.
2646 The current group does not have to be one of these groups.
2648 Admin users are permitted to list the queue, and to carry out certain
2649 operations on messages, for example, to force delivery failures. It is also
2650 necessary to be an admin user in order to see the full information provided by
2651 the Exim monitor, and full debugging output.
2653 By default, the use of the &%-M%&, &%-q%&, &%-R%&, and &%-S%& options to cause
2654 Exim to attempt delivery of messages on its queue is restricted to admin users.
2655 However, this restriction can be relaxed by setting the &%prod_requires_admin%&
2656 option false (that is, specifying &%no_prod_requires_admin%&).
2658 Similarly, the use of the &%-bp%& option to list all the messages in the queue
2659 is restricted to admin users unless &%queue_list_requires_admin%& is set
2660 false.
2661 .endlist
2664 &*Warning*&: If you configure your system so that admin users are able to
2665 edit Exim's configuration file, you are giving those users an easy way of
2666 getting root. There is further discussion of this issue at the start of chapter
2667 &<<CHAPconf>>&.
2672 .section "Command line options" "SECID39"
2673 Exim's command line options are described in alphabetical order below. If none
2674 of the options that specifies a specific action (such as starting the daemon or
2675 a queue runner, or testing an address, or receiving a message in a specific
2676 format, or listing the queue) are present, and there is at least one argument
2677 on the command line, &%-bm%& (accept a local message on the standard input,
2678 with the arguments specifying the recipients) is assumed. Otherwise, Exim
2679 outputs a brief message about itself and exits.
2681 . ////////////////////////////////////////////////////////////////////////////
2682 . Insert a stylized XML comment here, to identify the start of the command line
2683 . options. This is for the benefit of the Perl script that automatically
2684 . creates a man page for the options.
2685 . ////////////////////////////////////////////////////////////////////////////
2687 .literal xml
2688 <!-- === Start of command line options === -->
2689 .literal off
2692 .vlist
2693 .vitem &%--%&
2694 .oindex "--"
2695 .cindex "options" "command line; terminating"
2696 This is a pseudo-option whose only purpose is to terminate the options and
2697 therefore to cause subsequent command line items to be treated as arguments
2698 rather than options, even if they begin with hyphens.
2700 .vitem &%--help%&
2701 .oindex "&%--help%&"
2702 This option causes Exim to output a few sentences stating what it is.
2703 The same output is generated if the Exim binary is called with no options and
2704 no arguments.
2706 .vitem &%--version%&
2707 .oindex "&%--version%&"
2708 This option is an alias for &%-bV%& and causes version information to be
2709 displayed.
2711 .vitem &%-Ac%& &&&
2712 &%-Am%&
2713 .oindex "&%-Ac%&"
2714 .oindex "&%-Am%&"
2715 These options are used by Sendmail for selecting configuration files and are
2716 ignored by Exim.
2718 .vitem &%-B%&<&'type'&>
2719 .oindex "&%-B%&"
2720 .cindex "8-bit characters"
2721 .cindex "Sendmail compatibility" "8-bit characters"
2722 This is a Sendmail option for selecting 7 or 8 bit processing. Exim is 8-bit
2723 clean; it ignores this option.
2725 .vitem &%-bd%&
2726 .oindex "&%-bd%&"
2727 .cindex "daemon"
2728 .cindex "SMTP" "listener"
2729 .cindex "queue runner"
2730 This option runs Exim as a daemon, awaiting incoming SMTP connections. Usually
2731 the &%-bd%& option is combined with the &%-q%&<&'time'&> option, to specify
2732 that the daemon should also initiate periodic queue runs.
2734 The &%-bd%& option can be used only by an admin user. If either of the &%-d%&
2735 (debugging) or &%-v%& (verifying) options are set, the daemon does not
2736 disconnect from the controlling terminal. When running this way, it can be
2737 stopped by pressing ctrl-C.
2739 By default, Exim listens for incoming connections to the standard SMTP port on
2740 all the host's running interfaces. However, it is possible to listen on other
2741 ports, on multiple ports, and only on specific interfaces. Chapter
2742 &<<CHAPinterfaces>>& contains a description of the options that control this.
2744 When a listening daemon
2745 .cindex "daemon" "process id (pid)"
2746 .cindex "pid (process id)" "of daemon"
2747 is started without the use of &%-oX%& (that is, without overriding the normal
2748 configuration), it writes its process id to a file called &_exim-daemon.pid_&
2749 in Exim's spool directory. This location can be overridden by setting
2750 PID_FILE_PATH in &_Local/Makefile_&. The file is written while Exim is still
2751 running as root.
2753 When &%-oX%& is used on the command line to start a listening daemon, the
2754 process id is not written to the normal pid file path. However, &%-oP%& can be
2755 used to specify a path on the command line if a pid file is required.
2757 The SIGHUP signal
2758 .cindex "SIGHUP"
2759 .cindex "daemon" "restarting"
2760 can be used to cause the daemon to re-execute itself. This should be done
2761 whenever Exim's configuration file, or any file that is incorporated into it by
2762 means of the &%.include%& facility, is changed, and also whenever a new version
2763 of Exim is installed. It is not necessary to do this when other files that are
2764 referenced from the configuration (for example, alias files) are changed,
2765 because these are reread each time they are used.
2767 .vitem &%-bdf%&
2768 .oindex "&%-bdf%&"
2769 This option has the same effect as &%-bd%& except that it never disconnects
2770 from the controlling terminal, even when no debugging is specified.
2772 .vitem &%-be%&
2773 .oindex "&%-be%&"
2774 .cindex "testing" "string expansion"
2775 .cindex "expansion" "testing"
2776 Run Exim in expansion testing mode. Exim discards its root privilege, to
2777 prevent ordinary users from using this mode to read otherwise inaccessible
2778 files. If no arguments are given, Exim runs interactively, prompting for lines
2779 of data. Otherwise, it processes each argument in turn.
2781 If Exim was built with USE_READLINE=yes in &_Local/Makefile_&, it tries
2782 to load the &%libreadline%& library dynamically whenever the &%-be%& option is
2783 used without command line arguments. If successful, it uses the &[readline()]&
2784 function, which provides extensive line-editing facilities, for reading the
2785 test data. A line history is supported.
2787 Long expansion expressions can be split over several lines by using backslash
2788 continuations. As in Exim's run time configuration, white space at the start of
2789 continuation lines is ignored. Each argument or data line is passed through the
2790 string expansion mechanism, and the result is output. Variable values from the
2791 configuration file (for example, &$qualify_domain$&) are available, but no
2792 message-specific values (such as &$message_exim_id$&) are set, because no message
2793 is being processed (but see &%-bem%& and &%-Mset%&).
2795 &*Note*&: If you use this mechanism to test lookups, and you change the data
2796 files or databases you are using, you must exit and restart Exim before trying
2797 the same lookup again. Otherwise, because each Exim process caches the results
2798 of lookups, you will just get the same result as before.
2800 .vitem &%-bem%&&~<&'filename'&>
2801 .oindex "&%-bem%&"
2802 .cindex "testing" "string expansion"
2803 .cindex "expansion" "testing"
2804 This option operates like &%-be%& except that it must be followed by the name
2805 of a file. For example:
2806 .code
2807 exim -bem /tmp/testmessage
2808 .endd
2809 The file is read as a message (as if receiving a locally-submitted non-SMTP
2810 message) before any of the test expansions are done. Thus, message-specific
2811 variables such as &$message_size$& and &$header_from:$& are available. However,
2812 no &'Received:'& header is added to the message. If the &%-t%& option is set,
2813 recipients are read from the headers in the normal way, and are shown in the
2814 &$recipients$& variable. Note that recipients cannot be given on the command
2815 line, because further arguments are taken as strings to expand (just like
2816 &%-be%&).
2818 .vitem &%-bF%&&~<&'filename'&>
2819 .oindex "&%-bF%&"
2820 .cindex "system filter" "testing"
2821 .cindex "testing" "system filter"
2822 This option is the same as &%-bf%& except that it assumes that the filter being
2823 tested is a system filter. The additional commands that are available only in
2824 system filters are recognized.
2826 .vitem &%-bf%&&~<&'filename'&>
2827 .oindex "&%-bf%&"
2828 .cindex "filter" "testing"
2829 .cindex "testing" "filter file"
2830 .cindex "forward file" "testing"
2831 .cindex "testing" "forward file"
2832 .cindex "Sieve filter" "testing"
2833 This option runs Exim in user filter testing mode; the file is the filter file
2834 to be tested, and a test message must be supplied on the standard input. If
2835 there are no message-dependent tests in the filter, an empty file can be
2836 supplied.
2838 If you want to test a system filter file, use &%-bF%& instead of &%-bf%&. You
2839 can use both &%-bF%& and &%-bf%& on the same command, in order to test a system
2840 filter and a user filter in the same run. For example:
2841 .code
2842 exim -bF /system/filter -bf /user/filter </test/message
2843 .endd
2844 This is helpful when the system filter adds header lines or sets filter
2845 variables that are used by the user filter.
2847 If the test filter file does not begin with one of the special lines
2848 .code
2849 # Exim filter
2850 # Sieve filter
2851 .endd
2852 it is taken to be a normal &_.forward_& file, and is tested for validity under
2853 that interpretation. See sections &<<SECTitenonfilred>>& to
2854 &<<SECTspecitredli>>& for a description of the possible contents of non-filter
2855 redirection lists.
2857 The result of an Exim command that uses &%-bf%&, provided no errors are
2858 detected, is a list of the actions that Exim would try to take if presented
2859 with the message for real. More details of filter testing are given in the
2860 separate document entitled &'Exim's interfaces to mail filtering'&.
2862 When testing a filter file,
2863 .cindex "&""From""& line"
2864 .cindex "envelope sender"
2865 .oindex "&%-f%&" "for filter testing"
2866 the envelope sender can be set by the &%-f%& option,
2867 or by a &"From&~"& line at the start of the test message. Various parameters
2868 that would normally be taken from the envelope recipient address of the message
2869 can be set by means of additional command line options (see the next four
2870 options).
2872 .vitem &%-bfd%&&~<&'domain'&>
2873 .oindex "&%-bfd%&"
2874 .vindex "&$qualify_domain$&"
2875 This sets the domain of the recipient address when a filter file is being
2876 tested by means of the &%-bf%& option. The default is the value of
2877 &$qualify_domain$&.
2879 .vitem &%-bfl%&&~<&'local&~part'&>
2880 .oindex "&%-bfl%&"
2881 This sets the local part of the recipient address when a filter file is being
2882 tested by means of the &%-bf%& option. The default is the username of the
2883 process that calls Exim. A local part should be specified with any prefix or
2884 suffix stripped, because that is how it appears to the filter when a message is
2885 actually being delivered.
2887 .vitem &%-bfp%&&~<&'prefix'&>
2888 .oindex "&%-bfp%&"
2889 This sets the prefix of the local part of the recipient address when a filter
2890 file is being tested by means of the &%-bf%& option. The default is an empty
2891 prefix.
2893 .vitem &%-bfs%&&~<&'suffix'&>
2894 .oindex "&%-bfs%&"
2895 This sets the suffix of the local part of the recipient address when a filter
2896 file is being tested by means of the &%-bf%& option. The default is an empty
2897 suffix.
2899 .vitem &%-bh%&&~<&'IP&~address'&>
2900 .oindex "&%-bh%&"
2901 .cindex "testing" "incoming SMTP"
2902 .cindex "SMTP" "testing incoming"
2903 .cindex "testing" "relay control"
2904 .cindex "relaying" "testing configuration"
2905 .cindex "policy control" "testing"
2906 .cindex "debugging" "&%-bh%& option"
2907 This option runs a fake SMTP session as if from the given IP address, using the
2908 standard input and output. The IP address may include a port number at the end,
2909 after a full stop. For example:
2910 .code
2911 exim -bh
2912 exim -bh fe80::a00:20ff:fe86:a061.5678
2913 .endd
2914 When an IPv6 address is given, it is converted into canonical form. In the case
2915 of the second example above, the value of &$sender_host_address$& after
2916 conversion to the canonical form is
2917 &`fe80:0000:0000:0a00:20ff:fe86:a061.5678`&.
2919 Comments as to what is going on are written to the standard error file. These
2920 include lines beginning with &"LOG"& for anything that would have been logged.
2921 This facility is provided for testing configuration options for incoming
2922 messages, to make sure they implement the required policy. For example, you can
2923 test your relay controls using &%-bh%&.
2925 &*Warning 1*&:
2926 .cindex "RFC 1413"
2927 You can test features of the configuration that rely on ident (RFC 1413)
2928 information by using the &%-oMt%& option. However, Exim cannot actually perform
2929 an ident callout when testing using &%-bh%& because there is no incoming SMTP
2930 connection.
2932 &*Warning 2*&: Address verification callouts (see section &<<SECTcallver>>&)
2933 are also skipped when testing using &%-bh%&. If you want these callouts to
2934 occur, use &%-bhc%& instead.
2936 Messages supplied during the testing session are discarded, and nothing is
2937 written to any of the real log files. There may be pauses when DNS (and other)
2938 lookups are taking place, and of course these may time out. The &%-oMi%& option
2939 can be used to specify a specific IP interface and port if this is important,
2940 and &%-oMaa%& and &%-oMai%& can be used to set parameters as if the SMTP
2941 session were authenticated.
2943 The &'exim_checkaccess'& utility is a &"packaged"& version of &%-bh%& whose
2944 output just states whether a given recipient address from a given host is
2945 acceptable or not. See section &<<SECTcheckaccess>>&.
2947 Features such as authentication and encryption, where the client input is not
2948 plain text, cannot easily be tested with &%-bh%&. Instead, you should use a
2949 specialized SMTP test program such as
2950 &url(http://jetmore.org/john/code/#swaks,swaks).
2952 .vitem &%-bhc%&&~<&'IP&~address'&>
2953 .oindex "&%-bhc%&"
2954 This option operates in the same way as &%-bh%&, except that address
2955 verification callouts are performed if required. This includes consulting and
2956 updating the callout cache database.
2958 .vitem &%-bi%&
2959 .oindex "&%-bi%&"
2960 .cindex "alias file" "building"
2961 .cindex "building alias file"
2962 .cindex "Sendmail compatibility" "&%-bi%& option"
2963 Sendmail interprets the &%-bi%& option as a request to rebuild its alias file.
2964 Exim does not have the concept of a single alias file, and so it cannot mimic
2965 this behaviour. However, calls to &_/usr/lib/sendmail_& with the &%-bi%& option
2966 tend to appear in various scripts such as NIS make files, so the option must be
2967 recognized.
2969 If &%-bi%& is encountered, the command specified by the &%bi_command%&
2970 configuration option is run, under the uid and gid of the caller of Exim. If
2971 the &%-oA%& option is used, its value is passed to the command as an argument.
2972 The command set by &%bi_command%& may not contain arguments. The command can
2973 use the &'exim_dbmbuild'& utility, or some other means, to rebuild alias files
2974 if this is required. If the &%bi_command%& option is not set, calling Exim with
2975 &%-bi%& is a no-op.
2977 . // Keep :help first, then the rest in alphabetical order
2978 .vitem &%-bI:help%&
2979 .oindex "&%-bI:help%&"
2980 .cindex "querying exim information"
2981 We shall provide various options starting &`-bI:`& for querying Exim for
2982 information. The output of many of these will be intended for machine
2983 consumption. This one is not. The &%-bI:help%& option asks Exim for a
2984 synopsis of supported options beginning &`-bI:`&. Use of any of these
2985 options shall cause Exim to exit after producing the requested output.
2987 .vitem &%-bI:dscp%&
2988 .oindex "&%-bI:dscp%&"
2989 .cindex "DSCP" "values"
2990 This option causes Exim to emit an alphabetically sorted list of all
2991 recognised DSCP names.
2993 .vitem &%-bI:sieve%&
2994 .oindex "&%-bI:sieve%&"
2995 .cindex "Sieve filter" "capabilities"
2996 This option causes Exim to emit an alphabetically sorted list of all supported
2997 Sieve protocol extensions on stdout, one per line. This is anticipated to be
2998 useful for ManageSieve (RFC 5804) implementations, in providing that protocol's
2999 &`SIEVE`& capability response line. As the precise list may depend upon
3000 compile-time build options, which this option will adapt to, this is the only
3001 way to guarantee a correct response.
3003 .vitem &%-bm%&
3004 .oindex "&%-bm%&"
3005 .cindex "local message reception"
3006 This option runs an Exim receiving process that accepts an incoming,
3007 locally-generated message on the standard input. The recipients are given as the
3008 command arguments (except when &%-t%& is also present &-- see below). Each
3009 argument can be a comma-separated list of RFC 2822 addresses. This is the
3010 default option for selecting the overall action of an Exim call; it is assumed
3011 if no other conflicting option is present.
3013 If any addresses in the message are unqualified (have no domain), they are
3014 qualified by the values of the &%qualify_domain%& or &%qualify_recipient%&
3015 options, as appropriate. The &%-bnq%& option (see below) provides a way of
3016 suppressing this for special cases.
3018 Policy checks on the contents of local messages can be enforced by means of
3019 the non-SMTP ACL. See chapter &<<CHAPACL>>& for details.
3021 .cindex "return code" "for &%-bm%&"
3022 The return code is zero if the message is successfully accepted. Otherwise, the
3023 action is controlled by the &%-oe%&&'x'& option setting &-- see below.
3025 The format
3026 .cindex "message" "format"
3027 .cindex "format" "message"
3028 .cindex "&""From""& line"
3029 .cindex "UUCP" "&""From""& line"
3030 .cindex "Sendmail compatibility" "&""From""& line"
3031 of the message must be as defined in RFC 2822, except that, for
3032 compatibility with Sendmail and Smail, a line in one of the forms
3033 .code
3034 From sender Fri Jan 5 12:55 GMT 1997
3035 From sender Fri, 5 Jan 97 12:55:01
3036 .endd
3037 (with the weekday optional, and possibly with additional text after the date)
3038 is permitted to appear at the start of the message. There appears to be no
3039 authoritative specification of the format of this line. Exim recognizes it by
3040 matching against the regular expression defined by the &%uucp_from_pattern%&
3041 option, which can be changed if necessary.
3043 .oindex "&%-f%&" "overriding &""From""& line"
3044 The specified sender is treated as if it were given as the argument to the
3045 &%-f%& option, but if a &%-f%& option is also present, its argument is used in
3046 preference to the address taken from the message. The caller of Exim must be a
3047 trusted user for the sender of a message to be set in this way.
3049 .vitem &%-bmalware%&&~<&'filename'&>
3050 .oindex "&%-bmalware%&"
3051 .cindex "testing", "malware"
3052 .cindex "malware scan test"
3053 This debugging option causes Exim to scan the given file or directory
3054 (depending on the used scanner interface),
3055 using the malware scanning framework. The option of &%av_scanner%& influences
3056 this option, so if &%av_scanner%&'s value is dependent upon an expansion then
3057 the expansion should have defaults which apply to this invocation. ACLs are
3058 not invoked, so if &%av_scanner%& references an ACL variable then that variable
3059 will never be populated and &%-bmalware%& will fail.
3061 Exim will have changed working directory before resolving the filename, so
3062 using fully qualified pathnames is advisable. Exim will be running as the Exim
3063 user when it tries to open the file, rather than as the invoking user.
3064 This option requires admin privileges.
3066 The &%-bmalware%& option will not be extended to be more generally useful,
3067 there are better tools for file-scanning. This option exists to help
3068 administrators verify their Exim and AV scanner configuration.
3070 .vitem &%-bnq%&
3071 .oindex "&%-bnq%&"
3072 .cindex "address qualification, suppressing"
3073 By default, Exim automatically qualifies unqualified addresses (those
3074 without domains) that appear in messages that are submitted locally (that
3075 is, not over TCP/IP). This qualification applies both to addresses in
3076 envelopes, and addresses in header lines. Sender addresses are qualified using
3077 &%qualify_domain%&, and recipient addresses using &%qualify_recipient%& (which
3078 defaults to the value of &%qualify_domain%&).
3080 Sometimes, qualification is not wanted. For example, if &%-bS%& (batch SMTP) is
3081 being used to re-submit messages that originally came from remote hosts after
3082 content scanning, you probably do not want to qualify unqualified addresses in
3083 header lines. (Such lines will be present only if you have not enabled a header
3084 syntax check in the appropriate ACL.)
3086 The &%-bnq%& option suppresses all qualification of unqualified addresses in
3087 messages that originate on the local host. When this is used, unqualified
3088 addresses in the envelope provoke errors (causing message rejection) and
3089 unqualified addresses in header lines are left alone.
3092 .vitem &%-bP%&
3093 .oindex "&%-bP%&"
3094 .cindex "configuration options" "extracting"
3095 .cindex "options" "configuration &-- extracting"
3096 If this option is given with no arguments, it causes the values of all Exim's
3097 main configuration options to be written to the standard output. The values
3098 of one or more specific options can be requested by giving their names as
3099 arguments, for example:
3100 .code
3101 exim -bP qualify_domain hold_domains
3102 .endd
3103 .cindex "hiding configuration option values"
3104 .cindex "configuration options" "hiding value of"
3105 .cindex "options" "hiding value of"
3106 However, any option setting that is preceded by the word &"hide"& in the
3107 configuration file is not shown in full, except to an admin user. For other
3108 users, the output is as in this example:
3109 .code
3110 mysql_servers = <value not displayable>
3111 .endd
3112 If &%config%& is given as an argument, the config is
3113 output, as it was parsed, any include file resolved, any comment removed.
3115 If &%config_file%& is given as an argument, the name of the run time
3116 configuration file is output. (&%configure_file%& works too, for
3117 backward compatibility.)
3118 If a list of configuration files was supplied, the value that is output here
3119 is the name of the file that was actually used.
3121 .cindex "options" "hiding name of"
3122 If the &%-n%& flag is given, then for most modes of &%-bP%& operation the
3123 name will not be output.
3125 .cindex "daemon" "process id (pid)"
3126 .cindex "pid (process id)" "of daemon"
3127 If &%log_file_path%& or &%pid_file_path%& are given, the names of the
3128 directories where log files and daemon pid files are written are output,
3129 respectively. If these values are unset, log files are written in a
3130 sub-directory of the spool directory called &%log%&, and the pid file is
3131 written directly into the spool directory.
3133 If &%-bP%& is followed by a name preceded by &`+`&, for example,
3134 .code
3135 exim -bP +local_domains
3136 .endd
3137 it searches for a matching named list of any type (domain, host, address, or
3138 local part) and outputs what it finds.
3140 .cindex "options" "router &-- extracting"
3141 .cindex "options" "transport &-- extracting"
3142 .cindex "options" "authenticator &-- extracting"
3143 If one of the words &%router%&, &%transport%&, or &%authenticator%& is given,
3144 followed by the name of an appropriate driver instance, the option settings for
3145 that driver are output. For example:
3146 .code
3147 exim -bP transport local_delivery
3148 .endd
3149 The generic driver options are output first, followed by the driver's private
3150 options. A list of the names of drivers of a particular type can be obtained by
3151 using one of the words &%router_list%&, &%transport_list%&, or
3152 &%authenticator_list%&, and a complete list of all drivers with their option
3153 settings can be obtained by using &%routers%&, &%transports%&, or
3154 &%authenticators%&.
3156 .cindex "environment"
3157 If &%environment%& is given as an argument, the set of environment
3158 variables is output, line by line. Using the &%-n%& flag suppresses the value of the
3159 variables.
3161 .cindex "options" "macro &-- extracting"
3162 If invoked by an admin user, then &%macro%&, &%macro_list%& and &%macros%&
3163 are available, similarly to the drivers. Because macros are sometimes used
3164 for storing passwords, this option is restricted.
3165 The output format is one item per line.
3167 .vitem &%-bp%&
3168 .oindex "&%-bp%&"
3169 .cindex "queue" "listing messages on"
3170 .cindex "listing" "messages on the queue"
3171 This option requests a listing of the contents of the mail queue on the
3172 standard output. If the &%-bp%& option is followed by a list of message ids,
3173 just those messages are listed. By default, this option can be used only by an
3174 admin user. However, the &%queue_list_requires_admin%& option can be set false
3175 to allow any user to see the queue.
3177 Each message on the queue is displayed as in the following example:
3178 .code
3179 25m 2.9K 0t5C6f-0000c8-00 <alice@wonderland.fict.example>
3180 red.king@looking-glass.fict.example
3181 <other addresses>
3182 .endd
3183 .cindex "message" "size in queue listing"
3184 .cindex "size" "of message"
3185 The first line contains the length of time the message has been on the queue
3186 (in this case 25 minutes), the size of the message (2.9K), the unique local
3187 identifier for the message, and the message sender, as contained in the
3188 envelope. For bounce messages, the sender address is empty, and appears as
3189 &"<>"&. If the message was submitted locally by an untrusted user who overrode
3190 the default sender address, the user's login name is shown in parentheses
3191 before the sender address.
3193 .cindex "frozen messages" "in queue listing"
3194 If the message is frozen (attempts to deliver it are suspended) then the text
3195 &"*** frozen ***"& is displayed at the end of this line.
3197 The recipients of the message (taken from the envelope, not the headers) are
3198 displayed on subsequent lines. Those addresses to which the message has already
3199 been delivered are marked with the letter D. If an original address gets
3200 expanded into several addresses via an alias or forward file, the original is
3201 displayed with a D only when deliveries for all of its child addresses are
3202 complete.
3205 .vitem &%-bpa%&
3206 .oindex "&%-bpa%&"
3207 This option operates like &%-bp%&, but in addition it shows delivered addresses
3208 that were generated from the original top level address(es) in each message by
3209 alias or forwarding operations. These addresses are flagged with &"+D"& instead
3210 of just &"D"&.
3213 .vitem &%-bpc%&
3214 .oindex "&%-bpc%&"
3215 .cindex "queue" "count of messages on"
3216 This option counts the number of messages on the queue, and writes the total
3217 to the standard output. It is restricted to admin users, unless
3218 &%queue_list_requires_admin%& is set false.
3221 .vitem &%-bpr%&
3222 .oindex "&%-bpr%&"
3223 This option operates like &%-bp%&, but the output is not sorted into
3224 chronological order of message arrival. This can speed it up when there are
3225 lots of messages on the queue, and is particularly useful if the output is
3226 going to be post-processed in a way that doesn't need the sorting.
3228 .vitem &%-bpra%&
3229 .oindex "&%-bpra%&"
3230 This option is a combination of &%-bpr%& and &%-bpa%&.
3232 .vitem &%-bpru%&
3233 .oindex "&%-bpru%&"
3234 This option is a combination of &%-bpr%& and &%-bpu%&.
3237 .vitem &%-bpu%&
3238 .oindex "&%-bpu%&"
3239 This option operates like &%-bp%& but shows only undelivered top-level
3240 addresses for each message displayed. Addresses generated by aliasing or
3241 forwarding are not shown, unless the message was deferred after processing by a
3242 router with the &%one_time%& option set.
3245 .vitem &%-brt%&
3246 .oindex "&%-brt%&"
3247 .cindex "testing" "retry configuration"
3248 .cindex "retry" "configuration testing"
3249 This option is for testing retry rules, and it must be followed by up to three
3250 arguments. It causes Exim to look for a retry rule that matches the values
3251 and to write it to the standard output. For example:
3252 .code
3253 exim -brt bach.comp.mus.example
3254 Retry rule: *.comp.mus.example F,2h,15m; F,4d,30m;
3255 .endd
3256 See chapter &<<CHAPretry>>& for a description of Exim's retry rules. The first
3257 argument, which is required, can be a complete address in the form
3258 &'local_part@domain'&, or it can be just a domain name. If the second argument
3259 contains a dot, it is interpreted as an optional second domain name; if no
3260 retry rule is found for the first argument, the second is tried. This ties in
3261 with Exim's behaviour when looking for retry rules for remote hosts &-- if no
3262 rule is found that matches the host, one that matches the mail domain is
3263 sought. Finally, an argument that is the name of a specific delivery error, as
3264 used in setting up retry rules, can be given. For example:
3265 .code
3266 exim -brt haydn.comp.mus.example quota_3d
3267 Retry rule: *@haydn.comp.mus.example quota_3d F,1h,15m
3268 .endd
3270 .vitem &%-brw%&
3271 .oindex "&%-brw%&"
3272 .cindex "testing" "rewriting"
3273 .cindex "rewriting" "testing"
3274 This option is for testing address rewriting rules, and it must be followed by
3275 a single argument, consisting of either a local part without a domain, or a
3276 complete address with a fully qualified domain. Exim outputs how this address
3277 would be rewritten for each possible place it might appear. See chapter
3278 &<<CHAPrewrite>>& for further details.
3280 .vitem &%-bS%&
3281 .oindex "&%-bS%&"
3282 .cindex "SMTP" "batched incoming"
3283 .cindex "batched SMTP input"
3284 This option is used for batched SMTP input, which is an alternative interface
3285 for non-interactive local message submission. A number of messages can be
3286 submitted in a single run. However, despite its name, this is not really SMTP
3287 input. Exim reads each message's envelope from SMTP commands on the standard
3288 input, but generates no responses. If the caller is trusted, or
3289 &%untrusted_set_sender%& is set, the senders in the SMTP MAIL commands are
3290 believed; otherwise the sender is always the caller of Exim.
3292 The message itself is read from the standard input, in SMTP format (leading
3293 dots doubled), terminated by a line containing just a single dot. An error is
3294 provoked if the terminating dot is missing. A further message may then follow.
3296 As for other local message submissions, the contents of incoming batch SMTP
3297 messages can be checked using the non-SMTP ACL (see chapter &<<CHAPACL>>&).
3298 Unqualified addresses are automatically qualified using &%qualify_domain%& and
3299 &%qualify_recipient%&, as appropriate, unless the &%-bnq%& option is used.
3301 Some other SMTP commands are recognized in the input. HELO and EHLO act
3302 as RSET; VRFY, EXPN, ETRN, and HELP act as NOOP;
3303 QUIT quits, ignoring the rest of the standard input.
3305 .cindex "return code" "for &%-bS%&"
3306 If any error is encountered, reports are written to the standard output and
3307 error streams, and Exim gives up immediately. The return code is 0 if no error
3308 was detected; it is 1 if one or more messages were accepted before the error
3309 was detected; otherwise it is 2.
3311 More details of input using batched SMTP are given in section
3312 &<<SECTincomingbatchedSMTP>>&.
3314 .vitem &%-bs%&
3315 .oindex "&%-bs%&"
3316 .cindex "SMTP" "local input"
3317 .cindex "local SMTP input"
3318 This option causes Exim to accept one or more messages by reading SMTP commands
3319 on the standard input, and producing SMTP replies on the standard output. SMTP
3320 policy controls, as defined in ACLs (see chapter &<<CHAPACL>>&) are applied.
3321 Some user agents use this interface as a way of passing locally-generated
3322 messages to the MTA.
3324 In
3325 .cindex "sender" "source of"
3326 this usage, if the caller of Exim is trusted, or &%untrusted_set_sender%& is
3327 set, the senders of messages are taken from the SMTP MAIL commands.
3328 Otherwise the content of these commands is ignored and the sender is set up as
3329 the calling user. Unqualified addresses are automatically qualified using
3330 &%qualify_domain%& and &%qualify_recipient%&, as appropriate, unless the
3331 &%-bnq%& option is used.
3333 .cindex "inetd"
3334 The
3335 &%-bs%& option is also used to run Exim from &'inetd'&, as an alternative to
3336 using a listening daemon. Exim can distinguish the two cases by checking
3337 whether the standard input is a TCP/IP socket. When Exim is called from
3338 &'inetd'&, the source of the mail is assumed to be remote, and the comments
3339 above concerning senders and qualification do not apply. In this situation,
3340 Exim behaves in exactly the same way as it does when receiving a message via
3341 the listening daemon.
3343 .vitem &%-bt%&
3344 .oindex "&%-bt%&"
3345 .cindex "testing" "addresses"
3346 .cindex "address" "testing"
3347 This option runs Exim in address testing mode, in which each argument is taken
3348 as a recipient address to be tested for deliverability. The results are
3349 written to the standard output. If a test fails, and the caller is not an admin
3350 user, no details of the failure are output, because these might contain
3351 sensitive information such as usernames and passwords for database lookups.
3353 If no arguments are given, Exim runs in an interactive manner, prompting with a
3354 right angle bracket for addresses to be tested.
3356 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3357 &[readline()]& function, because it is running as &'root'& and there are
3358 security issues.
3360 Each address is handled as if it were the recipient address of a message
3361 (compare the &%-bv%& option). It is passed to the routers and the result is
3362 written to the standard output. However, any router that has
3363 &%no_address_test%& set is bypassed. This can make &%-bt%& easier to use for
3364 genuine routing tests if your first router passes everything to a scanner
3365 program.
3367 .cindex "return code" "for &%-bt%&"
3368 The return code is 2 if any address failed outright; it is 1 if no address
3369 failed outright but at least one could not be resolved for some reason. Return
3370 code 0 is given only when all addresses succeed.
3372 .cindex "duplicate addresses"
3373 &*Note*&: When actually delivering a message, Exim removes duplicate recipient
3374 addresses after routing is complete, so that only one delivery takes place.
3375 This does not happen when testing with &%-bt%&; the full results of routing are
3376 always shown.
3378 &*Warning*&: &%-bt%& can only do relatively simple testing. If any of the
3379 routers in the configuration makes any tests on the sender address of a
3380 message,
3381 .oindex "&%-f%&" "for address testing"
3382 you can use the &%-f%& option to set an appropriate sender when running
3383 &%-bt%& tests. Without it, the sender is assumed to be the calling user at the
3384 default qualifying domain. However, if you have set up (for example) routers
3385 whose behaviour depends on the contents of an incoming message, you cannot test
3386 those conditions using &%-bt%&. The &%-N%& option provides a possible way of
3387 doing such tests.
3389 .vitem &%-bV%&
3390 .oindex "&%-bV%&"
3391 .cindex "version number of Exim"
3392 This option causes Exim to write the current version number, compilation
3393 number, and compilation date of the &'exim'& binary to the standard output.
3394 It also lists the DBM library that is being used, the optional modules (such as
3395 specific lookup types), the drivers that are included in the binary, and the
3396 name of the run time configuration file that is in use.
3398 As part of its operation, &%-bV%& causes Exim to read and syntax check its
3399 configuration file. However, this is a static check only. It cannot check
3400 values that are to be expanded. For example, although a misspelt ACL verb is
3401 detected, an error in the verb's arguments is not. You cannot rely on &%-bV%&
3402 alone to discover (for example) all the typos in the configuration; some
3403 realistic testing is needed. The &%-bh%& and &%-N%& options provide more
3404 dynamic testing facilities.
3406 .vitem &%-bv%&
3407 .oindex "&%-bv%&"
3408 .cindex "verifying address" "using &%-bv%&"
3409 .cindex "address" "verification"
3410 This option runs Exim in address verification mode, in which each argument is
3411 taken as a recipient address to be verified by the routers. (This does
3412 not involve any verification callouts). During normal operation, verification
3413 happens mostly as a consequence processing a &%verify%& condition in an ACL
3414 (see chapter &<<CHAPACL>>&). If you want to test an entire ACL, possibly
3415 including callouts, see the &%-bh%& and &%-bhc%& options.
3417 If verification fails, and the caller is not an admin user, no details of the
3418 failure are output, because these might contain sensitive information such as
3419 usernames and passwords for database lookups.
3421 If no arguments are given, Exim runs in an interactive manner, prompting with a
3422 right angle bracket for addresses to be verified.
3424 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3425 &[readline()]& function, because it is running as &'exim'& and there are
3426 security issues.
3428 Verification differs from address testing (the &%-bt%& option) in that routers
3429 that have &%no_verify%& set are skipped, and if the address is accepted by a
3430 router that has &%fail_verify%& set, verification fails. The address is
3431 verified as a recipient if &%-bv%& is used; to test verification for a sender
3432 address, &%-bvs%& should be used.
3434 If the &%-v%& option is not set, the output consists of a single line for each
3435 address, stating whether it was verified or not, and giving a reason in the
3436 latter case. Without &%-v%&, generating more than one address by redirection
3437 causes verification to end successfully, without considering the generated
3438 addresses. However, if just one address is generated, processing continues,
3439 and the generated address must verify successfully for the overall verification
3440 to succeed.
3442 When &%-v%& is set, more details are given of how the address has been handled,
3443 and in the case of address redirection, all the generated addresses are also
3444 considered. Verification may succeed for some and fail for others.
3446 The
3447 .cindex "return code" "for &%-bv%&"
3448 return code is 2 if any address failed outright; it is 1 if no address
3449 failed outright but at least one could not be resolved for some reason. Return
3450 code 0 is given only when all addresses succeed.
3452 If any of the routers in the configuration makes any tests on the sender
3453 address of a message, you should use the &%-f%& option to set an appropriate
3454 sender when running &%-bv%& tests. Without it, the sender is assumed to be the
3455 calling user at the default qualifying domain.
3457 .vitem &%-bvs%&
3458 .oindex "&%-bvs%&"
3459 This option acts like &%-bv%&, but verifies the address as a sender rather
3460 than a recipient address. This affects any rewriting and qualification that
3461 might happen.
3463 .vitem &%-bw%&
3464 .oindex "&%-bw%&"
3465 .cindex "daemon"
3466 .cindex "inetd"
3467 .cindex "inetd" "wait mode"
3468 This option runs Exim as a daemon, awaiting incoming SMTP connections,
3469 similarly to the &%-bd%& option. All port specifications on the command-line
3470 and in the configuration file are ignored. Queue-running may not be specified.
3472 In this mode, Exim expects to be passed a socket as fd 0 (stdin) which is
3473 listening for connections. This permits the system to start up and have
3474 inetd (or equivalent) listen on the SMTP ports, starting an Exim daemon for
3475 each port only when the first connection is received.
3477 If the option is given as &%-bw%&<&'time'&> then the time is a timeout, after
3478 which the daemon will exit, which should cause inetd to listen once more.
3480 .vitem &%-C%&&~<&'filelist'&>
3481 .oindex "&%-C%&"
3482 .cindex "configuration file" "alternate"
3483 .cindex "CONFIGURE_FILE"
3484 .cindex "alternate configuration file"
3485 This option causes Exim to find the run time configuration file from the given
3486 list instead of from the list specified by the CONFIGURE_FILE
3487 compile-time setting. Usually, the list will consist of just a single file
3488 name, but it can be a colon-separated list of names. In this case, the first
3489 file that exists is used. Failure to open an existing file stops Exim from
3490 proceeding any further along the list, and an error is generated.
3492 When this option is used by a caller other than root, and the list is different
3493 from the compiled-in list, Exim gives up its root privilege immediately, and
3494 runs with the real and effective uid and gid set to those of the caller.
3495 However, if a TRUSTED_CONFIG_LIST file is defined in &_Local/Makefile_&, that
3496 file contains a list of full pathnames, one per line, for configuration files
3497 which are trusted. Root privilege is retained for any configuration file so
3498 listed, as long as the caller is the Exim user (or the user specified in the
3499 CONFIGURE_OWNER option, if any), and as long as the configuration file is
3500 not writeable by inappropriate users or groups.
3502 Leaving TRUSTED_CONFIG_LIST unset precludes the possibility of testing a
3503 configuration using &%-C%& right through message reception and delivery,
3504 even if the caller is root. The reception works, but by that time, Exim is
3505 running as the Exim user, so when it re-executes to regain privilege for the
3506 delivery, the use of &%-C%& causes privilege to be lost. However, root can
3507 test reception and delivery using two separate commands (one to put a message
3508 on the queue, using &%-odq%&, and another to do the delivery, using &%-M%&).
3510 If ALT_CONFIG_PREFIX is defined &_in Local/Makefile_&, it specifies a
3511 prefix string with which any file named in a &%-C%& command line option
3512 must start. In addition, the file name must not contain the sequence &`/../`&.
3513 However, if the value of the &%-C%& option is identical to the value of
3514 CONFIGURE_FILE in &_Local/Makefile_&, Exim ignores &%-C%& and proceeds as
3515 usual. There is no default setting for ALT_CONFIG_PREFIX; when it is
3516 unset, any file name can be used with &%-C%&.
3518 ALT_CONFIG_PREFIX can be used to confine alternative configuration files
3519 to a directory to which only root has access. This prevents someone who has
3520 broken into the Exim account from running a privileged Exim with an arbitrary
3521 configuration file.
3523 The &%-C%& facility is useful for ensuring that configuration files are
3524 syntactically correct, but cannot be used for test deliveries, unless the
3525 caller is privileged, or unless it is an exotic configuration that does not
3526 require privilege. No check is made on the owner or group of the files
3527 specified by this option.
3530 .vitem &%-D%&<&'macro'&>=<&'value'&>
3531 .oindex "&%-D%&"
3532 .cindex "macro" "setting on command line"
3533 This option can be used to override macro definitions in the configuration file
3534 (see section &<<SECTmacrodefs>>&). However, like &%-C%&, if it is used by an
3535 unprivileged caller, it causes Exim to give up its root privilege.
3536 If DISABLE_D_OPTION is defined in &_Local/Makefile_&, the use of &%-D%& is
3537 completely disabled, and its use causes an immediate error exit.
3539 If WHITELIST_D_MACROS is defined in &_Local/Makefile_& then it should be a
3540 colon-separated list of macros which are considered safe and, if &%-D%& only
3541 supplies macros from this list, and the values are acceptable, then Exim will
3542 not give up root privilege if the caller is root, the Exim run-time user, or
3543 the CONFIGURE_OWNER, if set. This is a transition mechanism and is expected
3544 to be removed in the future. Acceptable values for the macros satisfy the
3545 regexp: &`^[A-Za-z0-9_/.-]*$`&
3547 The entire option (including equals sign if present) must all be within one
3548 command line item. &%-D%& can be used to set the value of a macro to the empty
3549 string, in which case the equals sign is optional. These two commands are
3550 synonymous:
3551 .code
3552 exim -DABC ...
3553 exim -DABC= ...
3554 .endd
3555 To include spaces in a macro definition item, quotes must be used. If you use
3556 quotes, spaces are permitted around the macro name and the equals sign. For
3557 example:
3558 .code
3559 exim '-D ABC = something' ...
3560 .endd
3561 &%-D%& may be repeated up to 10 times on a command line.
3562 Only macro names up to 22 letters long can be set.
3565 .vitem &%-d%&<&'debug&~options'&>
3566 .oindex "&%-d%&"
3567 .cindex "debugging" "list of selectors"
3568 .cindex "debugging" "&%-d%& option"
3569 This option causes debugging information to be written to the standard
3570 error stream. It is restricted to admin users because debugging output may show
3571 database queries that contain password information. Also, the details of users'
3572 filter files should be protected. If a non-admin user uses &%-d%&, Exim
3573 writes an error message to the standard error stream and exits with a non-zero
3574 return code.
3576 When &%-d%& is used, &%-v%& is assumed. If &%-d%& is given on its own, a lot of
3577 standard debugging data is output. This can be reduced, or increased to include
3578 some more rarely needed information, by directly following &%-d%& with a string
3579 made up of names preceded by plus or minus characters. These add or remove sets
3580 of debugging data, respectively. For example, &%-d+filter%& adds filter
3581 debugging, whereas &%-d-all+filter%& selects only filter debugging. Note that
3582 no spaces are allowed in the debug setting. The available debugging categories
3583 are:
3584 .display
3585 &`acl `& ACL interpretation
3586 &`auth `& authenticators
3587 &`deliver `& general delivery logic
3588 &`dns `& DNS lookups (see also resolver)
3589 &`dnsbl `& DNS black list (aka RBL) code
3590 &`exec `& arguments for &[execv()]& calls
3591 &`expand `& detailed debugging for string expansions
3592 &`filter `& filter handling
3593 &`hints_lookup `& hints data lookups
3594 &`host_lookup `& all types of name-to-IP address handling
3595 &`ident `& ident lookup
3596 &`interface `& lists of local interfaces
3597 &`lists `& matching things in lists
3598 &`load `& system load checks
3599 &`local_scan `& can be used by &[local_scan()]& (see chapter &&&
3600 &<<CHAPlocalscan>>&)
3601 &`lookup `& general lookup code and all lookups
3602 &`memory `& memory handling
3603 &`pid `& add pid to debug output lines
3604 &`process_info `& setting info for the process log
3605 &`queue_run `& queue runs
3606 &`receive `& general message reception logic
3607 &`resolver `& turn on the DNS resolver's debugging output
3608 &`retry `& retry handling
3609 &`rewrite `& address rewriting
3610 &`route `& address routing
3611 &`timestamp `& add timestamp to debug output lines
3612 &`tls `& TLS logic
3613 &`transport `& transports
3614 &`uid `& changes of uid/gid and looking up uid/gid
3615 &`verify `& address verification logic
3616 &`all `& almost all of the above (see below), and also &%-v%&
3617 .endd
3618 The &`all`& option excludes &`memory`& when used as &`+all`&, but includes it
3619 for &`-all`&. The reason for this is that &`+all`& is something that people
3620 tend to use when generating debug output for Exim maintainers. If &`+memory`&
3621 is included, an awful lot of output that is very rarely of interest is
3622 generated, so it now has to be explicitly requested. However, &`-all`& does
3623 turn everything off.
3625 .cindex "resolver, debugging output"
3626 .cindex "DNS resolver, debugging output"
3627 The &`resolver`& option produces output only if the DNS resolver was compiled
3628 with DEBUG enabled. This is not the case in some operating systems. Also,
3629 unfortunately, debugging output from the DNS resolver is written to stdout
3630 rather than stderr.
3632 The default (&%-d%& with no argument) omits &`expand`&, &`filter`&,
3633 &`interface`&, &`load`&, &`memory`&, &`pid`&, &`resolver`&, and &`timestamp`&.
3634 However, the &`pid`& selector is forced when debugging is turned on for a
3635 daemon, which then passes it on to any re-executed Exims. Exim also
3636 automatically adds the pid to debug lines when several remote deliveries are
3637 run in parallel.
3639 The &`timestamp`& selector causes the current time to be inserted at the start
3640 of all debug output lines. This can be useful when trying to track down delays
3641 in processing.
3643 If the &%debug_print%& option is set in any driver, it produces output whenever
3644 any debugging is selected, or if &%-v%& is used.
3646 .vitem &%-dd%&<&'debug&~options'&>
3647 .oindex "&%-dd%&"
3648 This option behaves exactly like &%-d%& except when used on a command that
3649 starts a daemon process. In that case, debugging is turned off for the
3650 subprocesses that the daemon creates. Thus, it is useful for monitoring the
3651 behaviour of the daemon without creating as much output as full debugging does.
3653 .vitem &%-dropcr%&
3654 .oindex "&%-dropcr%&"
3655 This is an obsolete option that is now a no-op. It used to affect the way Exim
3656 handled CR and LF characters in incoming messages. What happens now is
3657 described in section &<<SECTlineendings>>&.
3659 .vitem &%-E%&
3660 .oindex "&%-E%&"
3661 .cindex "bounce message" "generating"
3662 This option specifies that an incoming message is a locally-generated delivery
3663 failure report. It is used internally by Exim when handling delivery failures
3664 and is not intended for external use. Its only effect is to stop Exim
3665 generating certain messages to the postmaster, as otherwise message cascades
3666 could occur in some situations. As part of the same option, a message id may
3667 follow the characters &%-E%&. If it does, the log entry for the receipt of the
3668 new message contains the id, following &"R="&, as a cross-reference.
3670 .vitem &%-e%&&'x'&
3671 .oindex "&%-e%&&'x'&"
3672 There are a number of Sendmail options starting with &%-oe%& which seem to be
3673 called by various programs without the leading &%o%& in the option. For
3674 example, the &%vacation%& program uses &%-eq%&. Exim treats all options of the
3675 form &%-e%&&'x'& as synonymous with the corresponding &%-oe%&&'x'& options.
3677 .vitem &%-F%&&~<&'string'&>
3678 .oindex "&%-F%&"
3679 .cindex "sender" "name"
3680 .cindex "name" "of sender"
3681 This option sets the sender's full name for use when a locally-generated
3682 message is being accepted. In the absence of this option, the user's &'gecos'&
3683 entry from the password data is used. As users are generally permitted to alter
3684 their &'gecos'& entries, no security considerations are involved. White space
3685 between &%-F%& and the <&'string'&> is optional.
3687 .vitem &%-f%&&~<&'address'&>
3688 .oindex "&%-f%&"
3689 .cindex "sender" "address"
3690 .cindex "address" "sender"
3691 .cindex "trusted users"
3692 .cindex "envelope sender"
3693 .cindex "user" "trusted"
3694 This option sets the address of the envelope sender of a locally-generated
3695 message (also known as the return path). The option can normally be used only
3696 by a trusted user, but &%untrusted_set_sender%& can be set to allow untrusted
3697 users to use it.
3699 Processes running as root or the Exim user are always trusted. Other
3700 trusted users are defined by the &%trusted_users%& or &%trusted_groups%&
3701 options. In the absence of &%-f%&, or if the caller is not trusted, the sender
3702 of a local message is set to the caller's login name at the default qualify
3703 domain.
3705 There is one exception to the restriction on the use of &%-f%&: an empty sender
3706 can be specified by any user, trusted or not, to create a message that can
3707 never provoke a bounce. An empty sender can be specified either as an empty
3708 string, or as a pair of angle brackets with nothing between them, as in these
3709 examples of shell commands:
3710 .code
3711 exim -f '<>' user@domain
3712 exim -f "" user@domain
3713 .endd
3714 In addition, the use of &%-f%& is not restricted when testing a filter file
3715 with &%-bf%& or when testing or verifying addresses using the &%-bt%& or
3716 &%-bv%& options.
3718 Allowing untrusted users to change the sender address does not of itself make
3719 it possible to send anonymous mail. Exim still checks that the &'From:'& header
3720 refers to the local user, and if it does not, it adds a &'Sender:'& header,
3721 though this can be overridden by setting &%no_local_from_check%&.
3723 White
3724 .cindex "&""From""& line"
3725 space between &%-f%& and the <&'address'&> is optional (that is, they can be
3726 given as two arguments or one combined argument). The sender of a
3727 locally-generated message can also be set (when permitted) by an initial
3728 &"From&~"& line in the message &-- see the description of &%-bm%& above &-- but
3729 if &%-f%& is also present, it overrides &"From&~"&.
3731 .vitem &%-G%&
3732 .oindex "&%-G%&"
3733 .cindex "submission fixups, suppressing (command-line)"
3734 This option is equivalent to an ACL applying:
3735 .code
3736 control = suppress_local_fixups
3737 .endd
3738 for every message received. Note that Sendmail will complain about such
3739 bad formatting, where Exim silently just does not fix it up. This may change
3740 in future.
3742 As this affects audit information, the caller must be a trusted user to use
3743 this option.
3745 .vitem &%-h%&&~<&'number'&>
3746 .oindex "&%-h%&"
3747 .cindex "Sendmail compatibility" "&%-h%& option ignored"
3748 This option is accepted for compatibility with Sendmail, but has no effect. (In
3749 Sendmail it overrides the &"hop count"& obtained by counting &'Received:'&
3750 headers.)
3752 .vitem &%-i%&
3753 .oindex "&%-i%&"
3754 .cindex "Solaris" "&'mail'& command"
3755 .cindex "dot" "in incoming non-SMTP message"
3756 This option, which has the same effect as &%-oi%&, specifies that a dot on a
3757 line by itself should not terminate an incoming, non-SMTP message. I can find
3758 no documentation for this option in Solaris 2.4 Sendmail, but the &'mailx'&
3759 command in Solaris 2.4 uses it. See also &%-ti%&.
3761 .vitem &%-L%&&~<&'tag'&>
3762 .oindex "&%-L%&"
3763 .cindex "syslog" "process name; set with flag"
3764 This option is equivalent to setting &%syslog_processname%& in the config
3765 file and setting &%log_file_path%& to &`syslog`&.
3766 Its use is restricted to administrators. The configuration file has to be
3767 read and parsed, to determine access rights, before this is set and takes
3768 effect, so early configuration file errors will not honour this flag.
3770 The tag should not be longer than 32 characters.
3772 .vitem &%-M%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3773 .oindex "&%-M%&"
3774 .cindex "forcing delivery"
3775 .cindex "delivery" "forcing attempt"
3776 .cindex "frozen messages" "forcing delivery"
3777 This option requests Exim to run a delivery attempt on each message in turn. If
3778 any of the messages are frozen, they are automatically thawed before the
3779 delivery attempt. The settings of &%queue_domains%&, &%queue_smtp_domains%&,
3780 and &%hold_domains%& are ignored.
3782 Retry
3783 .cindex "hints database" "overriding retry hints"
3784 hints for any of the addresses are overridden &-- Exim tries to deliver even if
3785 the normal retry time has not yet been reached. This option requires the caller
3786 to be an admin user. However, there is an option called &%prod_requires_admin%&
3787 which can be set false to relax this restriction (and also the same requirement
3788 for the &%-q%&, &%-R%&, and &%-S%& options).
3790 The deliveries happen synchronously, that is, the original Exim process does
3791 not terminate until all the delivery attempts have finished. No output is
3792 produced unless there is a serious error. If you want to see what is happening,
3793 use the &%-v%& option as well, or inspect Exim's main log.
3795 .vitem &%-Mar%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
3796 .oindex "&%-Mar%&"
3797 .cindex "message" "adding recipients"
3798 .cindex "recipient" "adding"
3799 This option requests Exim to add the addresses to the list of recipients of the
3800 message (&"ar"& for &"add recipients"&). The first argument must be a message
3801 id, and the remaining ones must be email addresses. However, if the message is
3802 active (in the middle of a delivery attempt), it is not altered. This option
3803 can be used only by an admin user.
3805 .vitem "&%-MC%&&~<&'transport'&>&~<&'hostname'&>&~<&'sequence&~number'&>&&&
3806 &~<&'message&~id'&>"
3807 .oindex "&%-MC%&"
3808 .cindex "SMTP" "passed connection"
3809 .cindex "SMTP" "multiple deliveries"
3810 .cindex "multiple SMTP deliveries"
3811 This option is not intended for use by external callers. It is used internally
3812 by Exim to invoke another instance of itself to deliver a waiting message using
3813 an existing SMTP connection, which is passed as the standard input. Details are
3814 given in chapter &<<CHAPSMTP>>&. This must be the final option, and the caller
3815 must be root or the Exim user in order to use it.
3817 .vitem &%-MCA%&
3818 .oindex "&%-MCA%&"
3819 This option is not intended for use by external callers. It is used internally
3820 by Exim in conjunction with the &%-MC%& option. It signifies that the
3821 connection to the remote host has been authenticated.
3823 .vitem &%-MCD%&
3824 .oindex "&%-MCD%&"
3825 This option is not intended for use by external callers. It is used internally
3826 by Exim in conjunction with the &%-MC%& option. It signifies that the
3827 remote host supports the ESMTP &_DSN_& extension.
3829 .vitem &%-MCG%&
3830 .oindex "&%-MCG%&"
3831 This option is not intended for use by external callers. It is used internally
3832 by Exim in conjunction with the &%-MC%& option. It signifies that an
3833 alternate queue is used, named by the following option.
3835 .vitem &%-MCP%&
3836 .oindex "&%-MCP%&"
3837 This option is not intended for use by external callers. It is used internally
3838 by Exim in conjunction with the &%-MC%& option. It signifies that the server to
3839 which Exim is connected supports pipelining.
3841 .vitem &%-MCQ%&&~<&'process&~id'&>&~<&'pipe&~fd'&>
3842 .oindex "&%-MCQ%&"
3843 This option is not intended for use by external callers. It is used internally
3844 by Exim in conjunction with the &%-MC%& option when the original delivery was
3845 started by a queue runner. It passes on the process id of the queue runner,
3846 together with the file descriptor number of an open pipe. Closure of the pipe
3847 signals the final completion of the sequence of processes that are passing
3848 messages through the same SMTP connection.
3850 .vitem &%-MCS%&
3851 .oindex "&%-MCS%&"
3852 This option is not intended for use by external callers. It is used internally
3853 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3854 SMTP SIZE option should be used on messages delivered down the existing
3855 connection.
3857 .vitem &%-MCT%&
3858 .oindex "&%-MCT%&"
3859 This option is not intended for use by external callers. It is used internally
3860 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3861 host to which Exim is connected supports TLS encryption.
3863 .vitem &%-Mc%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3864 .oindex "&%-Mc%&"
3865 .cindex "hints database" "not overridden by &%-Mc%&"
3866 .cindex "delivery" "manually started &-- not forced"
3867 This option requests Exim to run a delivery attempt on each message in turn,
3868 but unlike the &%-M%& option, it does check for retry hints, and respects any
3869 that are found. This option is not very useful to external callers. It is
3870 provided mainly for internal use by Exim when it needs to re-invoke itself in
3871 order to regain root privilege for a delivery (see chapter &<<CHAPsecurity>>&).
3872 However, &%-Mc%& can be useful when testing, in order to run a delivery that
3873 respects retry times and other options such as &%hold_domains%& that are
3874 overridden when &%-M%& is used. Such a delivery does not count as a queue run.
3875 If you want to run a specific delivery as if in a queue run, you should use
3876 &%-q%& with a message id argument. A distinction between queue run deliveries
3877 and other deliveries is made in one or two places.
3879 .vitem &%-Mes%&&~<&'message&~id'&>&~<&'address'&>
3880 .oindex "&%-Mes%&"
3881 .cindex "message" "changing sender"
3882 .cindex "sender" "changing"
3883 This option requests Exim to change the sender address in the message to the
3884 given address, which must be a fully qualified address or &"<>"& (&"es"& for
3885 &"edit sender"&). There must be exactly two arguments. The first argument must
3886 be a message id, and the second one an email address. However, if the message
3887 is active (in the middle of a delivery attempt), its status is not altered.
3888 This option can be used only by an admin user.
3890 .vitem &%-Mf%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3891 .oindex "&%-Mf%&"
3892 .cindex "freezing messages"
3893 .cindex "message" "manually freezing"
3894 This option requests Exim to mark each listed message as &"frozen"&. This
3895 prevents any delivery attempts taking place until the message is &"thawed"&,
3896 either manually or as a result of the &%auto_thaw%& configuration option.
3897 However, if any of the messages are active (in the middle of a delivery
3898 attempt), their status is not altered. This option can be used only by an admin
3899 user.
3901 .vitem &%-Mg%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3902 .oindex "&%-Mg%&"
3903 .cindex "giving up on messages"
3904 .cindex "message" "abandoning delivery attempts"
3905 .cindex "delivery" "abandoning further attempts"
3906 This option requests Exim to give up trying to deliver the listed messages,
3907 including any that are frozen. However, if any of the messages are active,
3908 their status is not altered. For non-bounce messages, a delivery error message
3909 is sent to the sender, containing the text &"cancelled by administrator"&.
3910 Bounce messages are just discarded. This option can be used only by an admin
3911 user.
3913 .vitem &%-Mmad%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3914 .oindex "&%-Mmad%&"
3915 .cindex "delivery" "cancelling all"
3916 This option requests Exim to mark all the recipient addresses in the messages
3917 as already delivered (&"mad"& for &"mark all delivered"&). However, if any
3918 message is active (in the middle of a delivery attempt), its status is not
3919 altered. This option can be used only by an admin user.
3921 .vitem &%-Mmd%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
3922 .oindex "&%-Mmd%&"
3923 .cindex "delivery" "cancelling by address"
3924 .cindex "recipient" "removing"
3925 .cindex "removing recipients"
3926 This option requests Exim to mark the given addresses as already delivered
3927 (&"md"& for &"mark delivered"&). The first argument must be a message id, and
3928 the remaining ones must be email addresses. These are matched to recipient
3929 addresses in the message in a case-sensitive manner. If the message is active
3930 (in the middle of a delivery attempt), its status is not altered. This option
3931 can be used only by an admin user.
3933 .vitem &%-Mrm%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3934 .oindex "&%-Mrm%&"
3935 .cindex "removing messages"
3936 .cindex "abandoning mail"
3937 .cindex "message" "manually discarding"
3938 This option requests Exim to remove the given messages from the queue. No
3939 bounce messages are sent; each message is simply forgotten. However, if any of
3940 the messages are active, their status is not altered. This option can be used
3941 only by an admin user or by the user who originally caused the message to be
3942 placed on the queue.
3944 .vitem &%-Mset%&&~<&'message&~id'&>
3945 .oindex "&%-Mset%&
3946 .cindex "testing" "string expansion"
3947 .cindex "expansion" "testing"
3948 This option is useful only in conjunction with &%-be%& (that is, when testing
3949 string expansions). Exim loads the given message from its spool before doing
3950 the test expansions, thus setting message-specific variables such as
3951 &$message_size$& and the header variables. The &$recipients$& variable is made
3952 available. This feature is provided to make it easier to test expansions that
3953 make use of these variables. However, this option can be used only by an admin
3954 user. See also &%-bem%&.
3956 .vitem &%-Mt%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3957 .oindex "&%-Mt%&"
3958 .cindex "thawing messages"
3959 .cindex "unfreezing messages"
3960 .cindex "frozen messages" "thawing"
3961 .cindex "message" "thawing frozen"
3962 This option requests Exim to &"thaw"& any of the listed messages that are
3963 &"frozen"&, so that delivery attempts can resume. However, if any of the
3964 messages are active, their status is not altered. This option can be used only
3965 by an admin user.
3967 .vitem &%-Mvb%&&~<&'message&~id'&>
3968 .oindex "&%-Mvb%&"
3969 .cindex "listing" "message body"
3970 .cindex "message" "listing body of"
3971 This option causes the contents of the message body (-D) spool file to be
3972 written to the standard output. This option can be used only by an admin user.
3974 .vitem &%-Mvc%&&~<&'message&~id'&>
3975 .oindex "&%-Mvc%&"
3976 .cindex "message" "listing in RFC 2822 format"
3977 .cindex "listing" "message in RFC 2822 format"
3978 This option causes a copy of the complete message (header lines plus body) to
3979 be written to the standard output in RFC 2822 format. This option can be used
3980 only by an admin user.
3982 .vitem &%-Mvh%&&~<&'message&~id'&>
3983 .oindex "&%-Mvh%&"
3984 .cindex "listing" "message headers"
3985 .cindex "header lines" "listing"
3986 .cindex "message" "listing header lines"
3987 This option causes the contents of the message headers (-H) spool file to be
3988 written to the standard output. This option can be used only by an admin user.
3990 .vitem &%-Mvl%&&~<&'message&~id'&>
3991 .oindex "&%-Mvl%&"
3992 .cindex "listing" "message log"
3993 .cindex "message" "listing message log"
3994 This option causes the contents of the message log spool file to be written to
3995 the standard output. This option can be used only by an admin user.
3997 .vitem &%-m%&
3998 .oindex "&%-m%&"
3999 This is apparently a synonym for &%-om%& that is accepted by Sendmail, so Exim
4000 treats it that way too.
4002 .vitem &%-N%&