[exim.git] / doc / doc-docbook / spec.xfpt
1 . $Cambridge: exim/doc/doc-docbook/spec.xfpt,v 1.82 2010/06/06 02:08:50 pdp Exp $
2 .
3 . /////////////////////////////////////////////////////////////////////////////
4 . This is the primary source of the Exim Manual. It is an xfpt document that is
5 . converted into DocBook XML for subsequent conversion into printing and online
6 . formats. The markup used herein is "standard" xfpt markup, with some extras.
7 . The markup is summarized in a file called Markup.txt.
8 .
9 . WARNING: When you use the .new macro, make sure it appears *before* any
10 . adjacent index items; otherwise you get an empty "paragraph" which causes
11 . unwanted vertical space.
12 . /////////////////////////////////////////////////////////////////////////////
14 .include stdflags
15 .include stdmacs
17 . /////////////////////////////////////////////////////////////////////////////
18 . This outputs the standard DocBook boilerplate.
19 . /////////////////////////////////////////////////////////////////////////////
21 .docbook
23 . /////////////////////////////////////////////////////////////////////////////
24 . These lines are processing instructions for the Simple DocBook Processor that
25 . Philip Hazel has developed as a less cumbersome way of making PostScript and
26 . PDFs than using xmlto and fop. They will be ignored by all other XML
27 . processors.
28 . /////////////////////////////////////////////////////////////////////////////
30 .literal xml
31 <?sdop
32 foot_right_recto="&chaptertitle; (&chapternumber;)"
33 foot_right_verso="&chaptertitle; (&chapternumber;)"
34 toc_chapter_blanks="yes,yes"
35 table_warn_overflow="overprint"
36 ?>
37 .literal off
39 . /////////////////////////////////////////////////////////////////////////////
40 . This generate the outermost <book> element that wraps then entire document.
41 . /////////////////////////////////////////////////////////////////////////////
43 .book
45 . /////////////////////////////////////////////////////////////////////////////
46 . These definitions set some parameters and save some typing. Remember that
47 . the <bookinfo> element must also be updated for each new edition.
48 . /////////////////////////////////////////////////////////////////////////////
50 .set previousversion "4.71"
51 .set version "4.72"
53 .set ACL "access control lists (ACLs)"
54 .set I "&nbsp;&nbsp;&nbsp;&nbsp;"
57 . /////////////////////////////////////////////////////////////////////////////
58 . Additional xfpt markup used by this document, over and above the default
59 . provided in the xfpt library.
60 . /////////////////////////////////////////////////////////////////////////////
62 . --- Override the &$ flag to automatically insert a $ with the variable name
64 .flag &$ $& "<varname>$" "</varname>"
66 . --- Short flags for daggers in option headings. They will always be inside
67 . --- an italic string, but we want the daggers to be roman.
69 .flag &!! "</emphasis>&dagger;<emphasis>"
70 .flag &!? "</emphasis>&Dagger;<emphasis>"
72 . --- A macro for an Exim option definition heading, generating a one-line
73 . --- table with four columns. For cases when the option name is given with
74 . --- a space, so that it can be split, a fifth argument is used for the
75 . --- index entry.
77 .macro option
78 .arg 5
79 .oindex "&%$5%&"
80 .endarg
81 .arg -5
82 .oindex "&%$1%&"
83 .endarg
84 .itable all 0 0 4 8* left 6* center 6* center 6* right
85 .row "&%$1%&" "Use: &'$2'&" "Type: &'$3'&" "Default: &'$4'&"
86 .endtable
87 .endmacro
89 . --- A macro for the common 2-column tables. The width of the first column
90 . --- is suitable for the many tables at the start of the main options chapter;
91 . --- the small number of other 2-column tables override it.
93 .macro table2 196pt 254pt
94 .itable none 0 0 2 $1 left $2 left
95 .endmacro
97 . --- A macro that generates .row, but puts &I; at the start of the first
98 . --- argument, thus indenting it. Assume a minimum of two arguments, and
99 . --- allow up to four arguments, which is as many as we'll ever need.
101 .macro irow
102 .arg 4
103 .row "&I;$1" "$2" "$3" "$4"
104 .endarg
105 .arg -4
106 .arg 3
107 .row "&I;$1" "$2" "$3"
108 .endarg
109 .arg -3
110 .row "&I;$1" "$2"
111 .endarg
112 .endarg
113 .endmacro
115 . --- Macros for option, variable, and concept index entries. For a "range"
116 . --- style of entry, use .scindex for the start and .ecindex for the end. The
117 . --- first argument of .scindex and the only argument of .ecindex must be the
118 . --- ID that ties them together.
120 .macro cindex
121 &<indexterm role="concept">&
122 &<primary>&$1&</primary>&
123 .arg 2
124 &<secondary>&$2&</secondary>&
125 .endarg
126 &</indexterm>&
127 .endmacro
129 .macro scindex
130 &<indexterm role="concept" id="$1" class="startofrange">&
131 &<primary>&$2&</primary>&
132 .arg 3
133 &<secondary>&$3&</secondary>&
134 .endarg
135 &</indexterm>&
136 .endmacro
138 .macro ecindex
139 &<indexterm role="concept" startref="$1" class="endofrange"/>&
140 .endmacro
142 .macro oindex
143 &<indexterm role="option">&
144 &<primary>&$1&</primary>&
145 .arg 2
146 &<secondary>&$2&</secondary>&
147 .endarg
148 &</indexterm>&
149 .endmacro
151 .macro vindex
152 &<indexterm role="variable">&
153 &<primary>&$1&</primary>&
154 .arg 2
155 &<secondary>&$2&</secondary>&
156 .endarg
157 &</indexterm>&
158 .endmacro
160 .macro index
161 .echo "** Don't use .index; use .cindex or .oindex or .vindex"
162 .endmacro
163 . ////////////////////////////////////////////////////////////////////////////
166 . ////////////////////////////////////////////////////////////////////////////
167 . The <bookinfo> element is removed from the XML before processing for Ascii
168 . output formats.
169 . ////////////////////////////////////////////////////////////////////////////
171 .literal xml
172 <bookinfo>
173 <title>Specification of the Exim Mail Transfer Agent</title>
174 <titleabbrev>The Exim MTA</titleabbrev>
175 <date>29 May 2010</date>
176 <author><firstname>Exim</firstname><surname>Maintainers</surname></author>
177 <authorinitials>EM</authorinitials>
178 <revhistory><revision>
179 <revnumber>4.72</revnumber>
180 <date>29 May 2010</date>
181 <authorinitials>EM</authorinitials>
182 </revision></revhistory>
183 <copyright><year>2009</year><holder>University of Cambridge</holder></copyright>
184 </bookinfo>
185 .literal off
188 . /////////////////////////////////////////////////////////////////////////////
189 . This chunk of literal XML implements index entries of the form "x, see y" and
190 . "x, see also y". However, the DocBook DTD doesn't allow <indexterm> entries
191 . at the top level, so we have to put the .chapter directive first.
192 . /////////////////////////////////////////////////////////////////////////////
194 .chapter "Introduction" "CHID1"
195 .literal xml
197 <indexterm role="variable">
198 <primary>$1, $2, etc.</primary>
199 <see><emphasis>numerical variables</emphasis></see>
200 </indexterm>
201 <indexterm role="concept">
202 <primary>address</primary>
203 <secondary>rewriting</secondary>
204 <see><emphasis>rewriting</emphasis></see>
205 </indexterm>
206 <indexterm role="concept">
207 <primary>Bounce Address Tag Validation</primary>
208 <see><emphasis>BATV</emphasis></see>
209 </indexterm>
210 <indexterm role="concept">
211 <primary>Client SMTP Authorization</primary>
212 <see><emphasis>CSA</emphasis></see>
213 </indexterm>
214 <indexterm role="concept">
215 <primary>CR character</primary>
216 <see><emphasis>carriage return</emphasis></see>
217 </indexterm>
218 <indexterm role="concept">
219 <primary>CRL</primary>
220 <see><emphasis>certificate revocation list</emphasis></see>
221 </indexterm>
222 <indexterm role="concept">
223 <primary>delivery</primary>
224 <secondary>failure report</secondary>
225 <see><emphasis>bounce message</emphasis></see>
226 </indexterm>
227 <indexterm role="concept">
228 <primary>dialup</primary>
229 <see><emphasis>intermittently connected hosts</emphasis></see>
230 </indexterm>
231 <indexterm role="concept">
232 <primary>exiscan</primary>
233 <see><emphasis>content scanning</emphasis></see>
234 </indexterm>
235 <indexterm role="concept">
236 <primary>failover</primary>
237 <see><emphasis>fallback</emphasis></see>
238 </indexterm>
239 <indexterm role="concept">
240 <primary>fallover</primary>
241 <see><emphasis>fallback</emphasis></see>
242 </indexterm>
243 <indexterm role="concept">
244 <primary>filter</primary>
245 <secondary>Sieve</secondary>
246 <see><emphasis>Sieve filter</emphasis></see>
247 </indexterm>
248 <indexterm role="concept">
249 <primary>ident</primary>
250 <see><emphasis>RFC 1413</emphasis></see>
251 </indexterm>
252 <indexterm role="concept">
253 <primary>LF character</primary>
254 <see><emphasis>linefeed</emphasis></see>
255 </indexterm>
256 <indexterm role="concept">
257 <primary>maximum</primary>
258 <seealso><emphasis>limit</emphasis></seealso>
259 </indexterm>
260 <indexterm role="concept">
261 <primary>monitor</primary>
262 <see><emphasis>Exim monitor</emphasis></see>
263 </indexterm>
264 <indexterm role="concept">
265 <primary>no_<emphasis>xxx</emphasis></primary>
266 <see>entry for xxx</see>
267 </indexterm>
268 <indexterm role="concept">
269 <primary>NUL</primary>
270 <see><emphasis>binary zero</emphasis></see>
271 </indexterm>
272 <indexterm role="concept">
273 <primary>passwd file</primary>
274 <see><emphasis>/etc/passwd</emphasis></see>
275 </indexterm>
276 <indexterm role="concept">
277 <primary>process id</primary>
278 <see><emphasis>pid</emphasis></see>
279 </indexterm>
280 <indexterm role="concept">
281 <primary>RBL</primary>
282 <see><emphasis>DNS list</emphasis></see>
283 </indexterm>
284 <indexterm role="concept">
285 <primary>redirection</primary>
286 <see><emphasis>address redirection</emphasis></see>
287 </indexterm>
288 <indexterm role="concept">
289 <primary>return path</primary>
290 <seealso><emphasis>envelope sender</emphasis></seealso>
291 </indexterm>
292 <indexterm role="concept">
293 <primary>scanning</primary>
294 <see><emphasis>content scanning</emphasis></see>
295 </indexterm>
296 <indexterm role="concept">
297 <primary>SSL</primary>
298 <see><emphasis>TLS</emphasis></see>
299 </indexterm>
300 <indexterm role="concept">
301 <primary>string</primary>
302 <secondary>expansion</secondary>
303 <see><emphasis>expansion</emphasis></see>
304 </indexterm>
305 <indexterm role="concept">
306 <primary>top bit</primary>
307 <see><emphasis>8-bit characters</emphasis></see>
308 </indexterm>
309 <indexterm role="concept">
310 <primary>variables</primary>
311 <see><emphasis>expansion, variables</emphasis></see>
312 </indexterm>
313 <indexterm role="concept">
314 <primary>zero, binary</primary>
315 <see><emphasis>binary zero</emphasis></see>
316 </indexterm>
318 .literal off
321 . /////////////////////////////////////////////////////////////////////////////
322 . This is the real start of the first chapter. See the comment above as to why
323 . we can't have the .chapter line here.
324 . chapter "Introduction"
325 . /////////////////////////////////////////////////////////////////////////////
327 Exim is a mail transfer agent (MTA) for hosts that are running Unix or
328 Unix-like operating systems. It was designed on the assumption that it would be
329 run on hosts that are permanently connected to the Internet. However, it can be
330 used on intermittently connected hosts with suitable configuration adjustments.
332 Configuration files currently exist for the following operating systems: AIX,
333 BSD/OS (aka BSDI), Darwin (Mac OS X), DGUX, Dragonfly, FreeBSD, GNU/Hurd,
334 GNU/Linux, HI-OSF (Hitachi), HI-UX, HP-UX, IRIX, MIPS RISCOS, NetBSD, OpenBSD,
335 OpenUNIX, QNX, SCO, SCO SVR4.2 (aka UNIX-SV), Solaris (aka SunOS5), SunOS4,
336 Tru64-Unix (formerly Digital UNIX, formerly DEC-OSF1), Ultrix, and Unixware.
337 Some of these operating systems are no longer current and cannot easily be
338 tested, so the configuration files may no longer work in practice.
340 There are also configuration files for compiling Exim in the Cygwin environment
341 that can be installed on systems running Windows. However, this document does
342 not contain any information about running Exim in the Cygwin environment.
344 The terms and conditions for the use and distribution of Exim are contained in
345 the file &_NOTICE_&. Exim is distributed under the terms of the GNU General
346 Public Licence, a copy of which may be found in the file &_LICENCE_&.
348 The use, supply or promotion of Exim for the purpose of sending bulk,
349 unsolicited electronic mail is incompatible with the basic aims of the program,
350 which revolve around the free provision of a service that enhances the quality
351 of personal communications. The author of Exim regards indiscriminate
352 mass-mailing as an antisocial, irresponsible abuse of the Internet.
354 Exim owes a great deal to Smail 3 and its author, Ron Karr. Without the
355 experience of running and working on the Smail 3 code, I could never have
356 contemplated starting to write a new MTA. Many of the ideas and user interfaces
357 were originally taken from Smail 3, though the actual code of Exim is entirely
358 new, and has developed far beyond the initial concept.
360 Many people, both in Cambridge and around the world, have contributed to the
361 development and the testing of Exim, and to porting it to various operating
362 systems. I am grateful to them all. The distribution now contains a file called
363 &_ACKNOWLEDGMENTS_&, in which I have started recording the names of
364 contributors.
367 .section "Exim documentation" "SECID1"
368 . Keep this example change bar when updating the documentation!
369 .new
370 .cindex "documentation"
371 This edition of the Exim specification applies to version &version; of Exim.
372 Substantive changes from the &previousversion; edition are marked in some
373 renditions of the document; this paragraph is so marked if the rendition is
374 capable of showing a change indicator.
375 .wen
377 This document is very much a reference manual; it is not a tutorial. The reader
378 is expected to have some familiarity with the SMTP mail transfer protocol and
379 with general Unix system administration. Although there are some discussions
380 and examples in places, the information is mostly organized in a way that makes
381 it easy to look up, rather than in a natural order for sequential reading.
382 Furthermore, the manual aims to cover every aspect of Exim in detail, including
383 a number of rarely-used, special-purpose features that are unlikely to be of
384 very wide interest.
386 .cindex "books about Exim"
387 An &"easier"& discussion of Exim which provides more in-depth explanatory,
388 introductory, and tutorial material can be found in a book entitled &'The Exim
389 SMTP Mail Server'& (second edition, 2007), published by UIT Cambridge
390 (&url(http://www.uit.co.uk/exim-book/)).
392 This book also contains a chapter that gives a general introduction to SMTP and
393 Internet mail. Inevitably, however, the book is unlikely to be fully up-to-date
394 with the latest release of Exim. (Note that the earlier book about Exim,
395 published by O'Reilly, covers Exim 3, and many things have changed in Exim 4.)
397 .cindex "Debian" "information sources"
398 If you are using a Debian distribution of Exim, you will find information about
399 Debian-specific features in the file
400 &_/usr/share/doc/exim4-base/README.Debian_&.
401 The command &(man update-exim.conf)& is another source of Debian-specific
402 information.
404 .cindex "&_doc/NewStuff_&"
405 .cindex "&_doc/ChangeLog_&"
406 .cindex "change log"
407 As the program develops, there may be features in newer versions that have not
408 yet made it into this document, which is updated only when the most significant
409 digit of the fractional part of the version number changes. Specifications of
410 new features that are not yet in this manual are placed in the file
411 &_doc/NewStuff_& in the Exim distribution.
413 Some features may be classified as &"experimental"&. These may change
414 incompatibly while they are developing, or even be withdrawn. For this reason,
415 they are not documented in this manual. Information about experimental features
416 can be found in the file &_doc/experimental.txt_&.
418 All changes to the program (whether new features, bug fixes, or other kinds of
419 change) are noted briefly in the file called &_doc/ChangeLog_&.
421 .cindex "&_doc/spec.txt_&"
422 This specification itself is available as an ASCII file in &_doc/spec.txt_& so
423 that it can easily be searched with a text editor. Other files in the &_doc_&
424 directory are:
426 .table2 100pt
427 .row &_OptionLists.txt_& "list of all options in alphabetical order"
428 .row &_dbm.discuss.txt_& "discussion about DBM libraries"
429 .row &_exim.8_& "a man page of Exim's command line options"
430 .row &_experimental.txt_& "documentation of experimental features"
431 .row &_filter.txt_& "specification of the filter language"
432 .row &_Exim3.upgrade_& "upgrade notes from release 2 to release 3"
433 .row &_Exim4.upgrade_& "upgrade notes from release 3 to release 4"
434 .endtable
436 The main specification and the specification of the filtering language are also
437 available in other formats (HTML, PostScript, PDF, and Texinfo). Section
438 &<<SECTavail>>& below tells you how to get hold of these.
442 .section "FTP and web sites" "SECID2"
443 .cindex "web site"
444 .cindex "FTP site"
445 The primary site for Exim source distributions is currently the University of
446 Cambridge's FTP site, whose contents are described in &'Where to find the Exim
447 distribution'& below. In addition, there is a web site and an FTP site at
448 &%exim.org%&. These are now also hosted at the University of Cambridge. The
449 &%exim.org%& site was previously hosted for a number of years by Energis
450 Squared, formerly Planet Online Ltd, whose support I gratefully acknowledge.
452 .cindex "wiki"
453 .cindex "FAQ"
454 As well as Exim distribution tar files, the Exim web site contains a number of
455 differently formatted versions of the documentation. A recent addition to the
456 online information is the Exim wiki (&url(http://wiki.exim.org)),
457 which contains what used to be a separate FAQ, as well as various other
458 examples, tips, and know-how that have been contributed by Exim users.
460 .cindex Bugzilla
461 An Exim Bugzilla exists at &url(http://bugs.exim.org). You can use
462 this to report bugs, and also to add items to the wish list. Please search
463 first to check that you are not duplicating a previous entry.
467 .section "Mailing lists" "SECID3"
468 .cindex "mailing lists" "for Exim users"
469 The following Exim mailing lists exist:
471 .table2 140pt
472 .row &'exim-users@exim.org'& "General discussion list"
473 .row &'exim-dev@exim.org'& "Discussion of bugs, enhancements, etc."
474 .row &'exim-announce@exim.org'& "Moderated, low volume announcements list"
475 .row &'exim-future@exim.org'& "Discussion of long-term development"
476 .endtable
478 You can subscribe to these lists, change your existing subscriptions, and view
479 or search the archives via the mailing lists link on the Exim home page.
480 .cindex "Debian" "mailing list for"
481 If you are using a Debian distribution of Exim, you may wish to subscribe to
482 the Debian-specific mailing list &'pkg-exim4-users@lists.alioth.debian.org'&
483 via this web page:
484 .display
485 &url(http://lists.alioth.debian.org/mailman/listinfo/pkg-exim4-users)
486 .endd
487 Please ask Debian-specific questions on this list and not on the general Exim
488 lists.
490 .section "Exim training" "SECID4"
491 .cindex "training courses"
492 Training courses in Cambridge (UK) used to be run annually by the author of
493 Exim, before he retired. At the time of writing, there are no plans to run
494 further Exim courses in Cambridge. However, if that changes, relevant
495 information will be posted at &url(http://www-tus.csx.cam.ac.uk/courses/exim/).
497 .section "Bug reports" "SECID5"
498 .cindex "bug reports"
499 .cindex "reporting bugs"
500 Reports of obvious bugs can be emailed to &'bugs@exim.org'& or reported
501 via the Bugzilla (&url(http://bugs.exim.org)). However, if you are unsure
502 whether some behaviour is a bug or not, the best thing to do is to post a
503 message to the &'exim-dev'& mailing list and have it discussed.
507 .section "Where to find the Exim distribution" "SECTavail"
508 .cindex "FTP site"
509 .cindex "distribution" "ftp site"
510 The master ftp site for the Exim distribution is
511 .display
512 &*ftp://ftp.csx.cam.ac.uk/pub/software/email/exim*&
513 .endd
514 This is mirrored by
515 .display
516 &*ftp://ftp.exim.org/pub/exim*&
517 .endd
518 The file references that follow are relative to the &_exim_& directories at
519 these sites. There are now quite a number of independent mirror sites around
520 the world. Those that I know about are listed in the file called &_Mirrors_&.
522 Within the &_exim_& directory there are subdirectories called &_exim3_& (for
523 previous Exim 3 distributions), &_exim4_& (for the latest Exim 4
524 distributions), and &_Testing_& for testing versions. In the &_exim4_&
525 subdirectory, the current release can always be found in files called
526 .display
527 &_exim-n.nn.tar.gz_&
528 &_exim-n.nn.tar.bz2_&
529 .endd
530 where &'n.nn'& is the highest such version number in the directory. The two
531 files contain identical data; the only difference is the type of compression.
532 The &_.bz2_& file is usually a lot smaller than the &_.gz_& file.
534 .cindex "distribution" "signing details"
535 .cindex "distribution" "public key"
536 .cindex "public key for signed distribution"
537 The distributions are currently signed with Nigel Metheringham's GPG key. The
538 corresponding public key is available from a number of keyservers, and there is
539 also a copy in the file &_nigel-pubkey.asc_&. The signatures for the tar bundles are
540 in:
541 .display
542 &_exim-n.nn.tar.gz.asc_&
543 &_exim-n.nn.tar.bz2.asc_&
544 .endd
545 For each released version, the log of changes is made separately available in a
546 separate file in the directory &_ChangeLogs_& so that it is possible to
547 find out what has changed without having to download the entire distribution.
549 .cindex "documentation" "available formats"
550 The main distribution contains ASCII versions of this specification and other
551 documentation; other formats of the documents are available in separate files
552 inside the &_exim4_& directory of the FTP site:
553 .display
554 &_exim-html-n.nn.tar.gz_&
555 &_exim-pdf-n.nn.tar.gz_&
556 &_exim-postscript-n.nn.tar.gz_&
557 &_exim-texinfo-n.nn.tar.gz_&
558 .endd
559 These tar files contain only the &_doc_& directory, not the complete
560 distribution, and are also available in &_.bz2_& as well as &_.gz_& forms.
563 .section "Limitations" "SECID6"
564 .ilist
565 .cindex "limitations of Exim"
566 .cindex "bang paths" "not handled by Exim"
567 Exim is designed for use as an Internet MTA, and therefore handles addresses in
568 RFC 2822 domain format only. It cannot handle UUCP &"bang paths"&, though
569 simple two-component bang paths can be converted by a straightforward rewriting
570 configuration. This restriction does not prevent Exim from being interfaced to
571 UUCP as a transport mechanism, provided that domain addresses are used.
572 .next
573 .cindex "domainless addresses"
574 .cindex "address" "without domain"
575 Exim insists that every address it handles has a domain attached. For incoming
576 local messages, domainless addresses are automatically qualified with a
577 configured domain value. Configuration options specify from which remote
578 systems unqualified addresses are acceptable. These are then qualified on
579 arrival.
580 .next
581 .cindex "transport" "external"
582 .cindex "external transports"
583 The only external transport mechanisms that are currently implemented are SMTP
584 and LMTP over a TCP/IP network (including support for IPv6). However, a pipe
585 transport is available, and there are facilities for writing messages to files
586 and pipes, optionally in &'batched SMTP'& format; these facilities can be used
587 to send messages to other transport mechanisms such as UUCP, provided they can
588 handle domain-style addresses. Batched SMTP input is also catered for.
589 .next
590 Exim is not designed for storing mail for dial-in hosts. When the volumes of
591 such mail are large, it is better to get the messages &"delivered"& into files
592 (that is, off Exim's queue) and subsequently passed on to the dial-in hosts by
593 other means.
594 .next
595 Although Exim does have basic facilities for scanning incoming messages, these
596 are not comprehensive enough to do full virus or spam scanning. Such operations
597 are best carried out using additional specialized software packages. If you
598 compile Exim with the content-scanning extension, straightforward interfaces to
599 a number of common scanners are provided.
600 .endlist
603 .section "Run time configuration" "SECID7"
604 Exim's run time configuration is held in a single text file that is divided
605 into a number of sections. The entries in this file consist of keywords and
606 values, in the style of Smail 3 configuration files. A default configuration
607 file which is suitable for simple online installations is provided in the
608 distribution, and is described in chapter &<<CHAPdefconfil>>& below.
611 .section "Calling interface" "SECID8"
612 .cindex "Sendmail compatibility" "command line interface"
613 Like many MTAs, Exim has adopted the Sendmail command line interface so that it
614 can be a straight replacement for &_/usr/lib/sendmail_& or
615 &_/usr/sbin/sendmail_& when sending mail, but you do not need to know anything
616 about Sendmail in order to run Exim. For actions other than sending messages,
617 Sendmail-compatible options also exist, but those that produce output (for
618 example, &%-bp%&, which lists the messages on the queue) do so in Exim's own
619 format. There are also some additional options that are compatible with Smail
620 3, and some further options that are new to Exim. Chapter &<<CHAPcommandline>>&
621 documents all Exim's command line options. This information is automatically
622 made into the man page that forms part of the Exim distribution.
624 Control of messages on the queue can be done via certain privileged command
625 line options. There is also an optional monitor program called &'eximon'&,
626 which displays current information in an X window, and which contains a menu
627 interface to Exim's command line administration options.
631 .section "Terminology" "SECID9"
632 .cindex "terminology definitions"
633 .cindex "body of message" "definition of"
634 The &'body'& of a message is the actual data that the sender wants to transmit.
635 It is the last part of a message, and is separated from the &'header'& (see
636 below) by a blank line.
638 .cindex "bounce message" "definition of"
639 When a message cannot be delivered, it is normally returned to the sender in a
640 delivery failure message or a &"non-delivery report"& (NDR). The term
641 &'bounce'& is commonly used for this action, and the error reports are often
642 called &'bounce messages'&. This is a convenient shorthand for &"delivery
643 failure error report"&. Such messages have an empty sender address in the
644 message's &'envelope'& (see below) to ensure that they cannot themselves give
645 rise to further bounce messages.
647 The term &'default'& appears frequently in this manual. It is used to qualify a
648 value which is used in the absence of any setting in the configuration. It may
649 also qualify an action which is taken unless a configuration setting specifies
650 otherwise.
652 The term &'defer'& is used when the delivery of a message to a specific
653 destination cannot immediately take place for some reason (a remote host may be
654 down, or a user's local mailbox may be full). Such deliveries are &'deferred'&
655 until a later time.
657 The word &'domain'& is sometimes used to mean all but the first component of a
658 host's name. It is &'not'& used in that sense here, where it normally refers to
659 the part of an email address following the @ sign.
661 .cindex "envelope, definition of"
662 .cindex "sender" "definition of"
663 A message in transit has an associated &'envelope'&, as well as a header and a
664 body. The envelope contains a sender address (to which bounce messages should
665 be delivered), and any number of recipient addresses. References to the
666 sender or the recipients of a message usually mean the addresses in the
667 envelope. An MTA uses these addresses for delivery, and for returning bounce
668 messages, not the addresses that appear in the header lines.
670 .cindex "message" "header, definition of"
671 .cindex "header section" "definition of"
672 The &'header'& of a message is the first part of a message's text, consisting
673 of a number of lines, each of which has a name such as &'From:'&, &'To:'&,
674 &'Subject:'&, etc. Long header lines can be split over several text lines by
675 indenting the continuations. The header is separated from the body by a blank
676 line.
678 .cindex "local part" "definition of"
679 .cindex "domain" "definition of"
680 The term &'local part'&, which is taken from RFC 2822, is used to refer to that
681 part of an email address that precedes the @ sign. The part that follows the
682 @ sign is called the &'domain'& or &'mail domain'&.
684 .cindex "local delivery" "definition of"
685 .cindex "remote delivery, definition of"
686 The terms &'local delivery'& and &'remote delivery'& are used to distinguish
687 delivery to a file or a pipe on the local host from delivery by SMTP over
688 TCP/IP to another host. As far as Exim is concerned, all hosts other than the
689 host it is running on are &'remote'&.
691 .cindex "return path" "definition of"
692 &'Return path'& is another name that is used for the sender address in a
693 message's envelope.
695 .cindex "queue" "definition of"
696 The term &'queue'& is used to refer to the set of messages awaiting delivery,
697 because this term is in widespread use in the context of MTAs. However, in
698 Exim's case the reality is more like a pool than a queue, because there is
699 normally no ordering of waiting messages.
701 .cindex "queue runner" "definition of"
702 The term &'queue runner'& is used to describe a process that scans the queue
703 and attempts to deliver those messages whose retry times have come. This term
704 is used by other MTAs, and also relates to the command &%runq%&, but in Exim
705 the waiting messages are normally processed in an unpredictable order.
707 .cindex "spool directory" "definition of"
708 The term &'spool directory'& is used for a directory in which Exim keeps the
709 messages on its queue &-- that is, those that it is in the process of
710 delivering. This should not be confused with the directory in which local
711 mailboxes are stored, which is called a &"spool directory"& by some people. In
712 the Exim documentation, &"spool"& is always used in the first sense.
719 . ////////////////////////////////////////////////////////////////////////////
720 . ////////////////////////////////////////////////////////////////////////////
722 .chapter "Incorporated code" "CHID2"
723 .cindex "incorporated code"
724 .cindex "regular expressions" "library"
725 .cindex "PCRE"
726 A number of pieces of external code are included in the Exim distribution.
728 .ilist
729 Regular expressions are supported in the main Exim program and in the
730 Exim monitor using the freely-distributable PCRE library, copyright
731 &copy; University of Cambridge. The source to PCRE is no longer shipped with
732 Exim, so you will need to use the version of PCRE shipped with your system,
733 or obtain and install the full version of the library from
734 &url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre).
735 .next
736 .cindex "cdb" "acknowledgment"
737 Support for the cdb (Constant DataBase) lookup method is provided by code
738 contributed by Nigel Metheringham of (at the time he contributed it) Planet
739 Online Ltd. The implementation is completely contained within the code of Exim.
740 It does not link against an external cdb library. The code contains the
741 following statements:
743 .blockquote
744 Copyright &copy; 1998 Nigel Metheringham, Planet Online Ltd
746 This program is free software; you can redistribute it and/or modify it under
747 the terms of the GNU General Public License as published by the Free Software
748 Foundation; either version 2 of the License, or (at your option) any later
749 version.
750 This code implements Dan Bernstein's Constant DataBase (cdb) spec. Information,
751 the spec and sample code for cdb can be obtained from
752 &url(http://www.pobox.com/~djb/cdb.html). This implementation borrows
753 some code from Dan Bernstein's implementation (which has no license
754 restrictions applied to it).
755 .endblockquote
756 .next
757 .cindex "SPA authentication"
758 .cindex "Samba project"
759 .cindex "Microsoft Secure Password Authentication"
760 Client support for Microsoft's &'Secure Password Authentication'& is provided
761 by code contributed by Marc Prud'hommeaux. Server support was contributed by
762 Tom Kistner. This includes code taken from the Samba project, which is released
763 under the Gnu GPL.
764 .next
765 .cindex "Cyrus"
766 .cindex "&'pwcheck'& daemon"
767 .cindex "&'pwauthd'& daemon"
768 Support for calling the Cyrus &'pwcheck'& and &'saslauthd'& daemons is provided
769 by code taken from the Cyrus-SASL library and adapted by Alexander S.
770 Sabourenkov. The permission notice appears below, in accordance with the
771 conditions expressed therein.
773 .blockquote
774 Copyright &copy; 2001 Carnegie Mellon University. All rights reserved.
776 Redistribution and use in source and binary forms, with or without
777 modification, are permitted provided that the following conditions
778 are met:
780 .olist
781 Redistributions of source code must retain the above copyright
782 notice, this list of conditions and the following disclaimer.
783 .next
784 Redistributions in binary form must reproduce the above copyright
785 notice, this list of conditions and the following disclaimer in
786 the documentation and/or other materials provided with the
787 distribution.
788 .next
789 The name &"Carnegie Mellon University"& must not be used to
790 endorse or promote products derived from this software without
791 prior written permission. For permission or any other legal
792 details, please contact
793 .display
794 Office of Technology Transfer
795 Carnegie Mellon University
796 5000 Forbes Avenue
797 Pittsburgh, PA 15213-3890
798 (412) 268-4387, fax: (412) 268-7395
799 tech-transfer@andrew.cmu.edu
800 .endd
801 .next
802 Redistributions of any form whatsoever must retain the following
803 acknowledgment:
805 &"This product includes software developed by Computing Services
806 at Carnegie Mellon University (&url(http://www.cmu.edu/computing/)."&
815 .endlist
816 .endblockquote
818 .next
819 .cindex "Exim monitor" "acknowledgment"
820 .cindex "X-windows"
821 .cindex "Athena"
822 The Exim Monitor program, which is an X-Window application, includes
823 modified versions of the Athena StripChart and TextPop widgets.
824 This code is copyright by DEC and MIT, and their permission notice appears
825 below, in accordance with the conditions expressed therein.
827 .blockquote
828 Copyright 1987, 1988 by Digital Equipment Corporation, Maynard, Massachusetts,
829 and the Massachusetts Institute of Technology, Cambridge, Massachusetts.
831 All Rights Reserved
833 Permission to use, copy, modify, and distribute this software and its
834 documentation for any purpose and without fee is hereby granted,
835 provided that the above copyright notice appear in all copies and that
836 both that copyright notice and this permission notice appear in
837 supporting documentation, and that the names of Digital or MIT not be
838 used in advertising or publicity pertaining to distribution of the
839 software without specific, written prior permission.
848 .endblockquote
850 .next
851 Many people have contributed code fragments, some large, some small, that were
852 not covered by any specific licence requirements. It is assumed that the
853 contributors are happy to see their code incorporated into Exim under the GPL.
854 .endlist
860 . ////////////////////////////////////////////////////////////////////////////
861 . ////////////////////////////////////////////////////////////////////////////
863 .chapter "How Exim receives and delivers mail" "CHID11" &&&
864 "Receiving and delivering mail"
867 .section "Overall philosophy" "SECID10"
868 .cindex "design philosophy"
869 Exim is designed to work efficiently on systems that are permanently connected
870 to the Internet and are handling a general mix of mail. In such circumstances,
871 most messages can be delivered immediately. Consequently, Exim does not
872 maintain independent queues of messages for specific domains or hosts, though
873 it does try to send several messages in a single SMTP connection after a host
874 has been down, and it also maintains per-host retry information.
877 .section "Policy control" "SECID11"
878 .cindex "policy control" "overview"
879 Policy controls are now an important feature of MTAs that are connected to the
880 Internet. Perhaps their most important job is to stop MTAs being abused as
881 &"open relays"& by misguided individuals who send out vast amounts of
882 unsolicited junk, and want to disguise its source. Exim provides flexible
883 facilities for specifying policy controls on incoming mail:
885 .ilist
886 .cindex "&ACL;" "introduction"
887 Exim 4 (unlike previous versions of Exim) implements policy controls on
888 incoming mail by means of &'Access Control Lists'& (ACLs). Each list is a
889 series of statements that may either grant or deny access. ACLs can be used at
890 several places in the SMTP dialogue while receiving a message from a remote
891 host. However, the most common places are after each RCPT command, and at the
892 very end of the message. The sysadmin can specify conditions for accepting or
893 rejecting individual recipients or the entire message, respectively, at these
894 two points (see chapter &<<CHAPACL>>&). Denial of access results in an SMTP
895 error code.
896 .next
897 An ACL is also available for locally generated, non-SMTP messages. In this
898 case, the only available actions are to accept or deny the entire message.
899 .next
900 When Exim is compiled with the content-scanning extension, facilities are
901 provided in the ACL mechanism for passing the message to external virus and/or
902 spam scanning software. The result of such a scan is passed back to the ACL,
903 which can then use it to decide what to do with the message.
904 .next
905 When a message has been received, either from a remote host or from the local
906 host, but before the final acknowledgment has been sent, a locally supplied C
907 function called &[local_scan()]& can be run to inspect the message and decide
908 whether to accept it or not (see chapter &<<CHAPlocalscan>>&). If the message
909 is accepted, the list of recipients can be modified by the function.
910 .next
911 Using the &[local_scan()]& mechanism is another way of calling external scanner
912 software. The &%SA-Exim%& add-on package works this way. It does not require
913 Exim to be compiled with the content-scanning extension.
914 .next
915 After a message has been accepted, a further checking mechanism is available in
916 the form of the &'system filter'& (see chapter &<<CHAPsystemfilter>>&). This
917 runs at the start of every delivery process.
918 .endlist
922 .section "User filters" "SECID12"
923 .cindex "filter" "introduction"
924 .cindex "Sieve filter"
925 In a conventional Exim configuration, users are able to run private filters by
926 setting up appropriate &_.forward_& files in their home directories. See
927 chapter &<<CHAPredirect>>& (about the &(redirect)& router) for the
928 configuration needed to support this, and the separate document entitled
929 &'Exim's interfaces to mail filtering'& for user details. Two different kinds
930 of filtering are available:
932 .ilist
933 Sieve filters are written in the standard filtering language that is defined
934 by RFC 3028.
935 .next
936 Exim filters are written in a syntax that is unique to Exim, but which is more
937 powerful than Sieve, which it pre-dates.
938 .endlist
940 User filters are run as part of the routing process, described below.
944 .section "Message identification" "SECTmessiden"
945 .cindex "message ids" "details of format"
946 .cindex "format" "of message id"
947 .cindex "id of message"
948 .cindex "base62"
949 .cindex "base36"
950 .cindex "Darwin"
951 .cindex "Cygwin"
952 Every message handled by Exim is given a &'message id'& which is sixteen
953 characters long. It is divided into three parts, separated by hyphens, for
954 example &`16VDhn-0001bo-D3`&. Each part is a sequence of letters and digits,
955 normally encoding numbers in base 62. However, in the Darwin operating
956 system (Mac OS X) and when Exim is compiled to run under Cygwin, base 36
957 (avoiding the use of lower case letters) is used instead, because the message
958 id is used to construct file names, and the names of files in those systems are
959 not always case-sensitive.
961 .cindex "pid (process id)" "re-use of"
962 The detail of the contents of the message id have changed as Exim has evolved.
963 Earlier versions relied on the operating system not re-using a process id (pid)
964 within one second. On modern operating systems, this assumption can no longer
965 be made, so the algorithm had to be changed. To retain backward compatibility,
966 the format of the message id was retained, which is why the following rules are
967 somewhat eccentric:
969 .ilist
970 The first six characters of the message id are the time at which the message
971 started to be received, to a granularity of one second. That is, this field
972 contains the number of seconds since the start of the epoch (the normal Unix
973 way of representing the date and time of day).
974 .next
975 After the first hyphen, the next six characters are the id of the process that
976 received the message.
977 .next
978 There are two different possibilities for the final two characters:
979 .olist
980 .oindex "&%localhost_number%&"
981 If &%localhost_number%& is not set, this value is the fractional part of the
982 time of reception, normally in units of 1/2000 of a second, but for systems
983 that must use base 36 instead of base 62 (because of case-insensitive file
984 systems), the units are 1/1000 of a second.
985 .next
986 If &%localhost_number%& is set, it is multiplied by 200 (100) and added to
987 the fractional part of the time, which in this case is in units of 1/200
988 (1/100) of a second.
989 .endlist
990 .endlist
992 After a message has been received, Exim waits for the clock to tick at the
993 appropriate resolution before proceeding, so that if another message is
994 received by the same process, or by another process with the same (re-used)
995 pid, it is guaranteed that the time will be different. In most cases, the clock
996 will already have ticked while the message was being received.
999 .section "Receiving mail" "SECID13"
1000 .cindex "receiving mail"
1001 .cindex "message" "reception"
1002 The only way Exim can receive mail from another host is using SMTP over
1003 TCP/IP, in which case the sender and recipient addresses are transferred using
1004 SMTP commands. However, from a locally running process (such as a user's MUA),
1005 there are several possibilities:
1007 .ilist
1008 If the process runs Exim with the &%-bm%& option, the message is read
1009 non-interactively (usually via a pipe), with the recipients taken from the
1010 command line, or from the body of the message if &%-t%& is also used.
1011 .next
1012 If the process runs Exim with the &%-bS%& option, the message is also read
1013 non-interactively, but in this case the recipients are listed at the start of
1014 the message in a series of SMTP RCPT commands, terminated by a DATA
1015 command. This is so-called &"batch SMTP"& format,
1016 but it isn't really SMTP. The SMTP commands are just another way of passing
1017 envelope addresses in a non-interactive submission.
1018 .next
1019 If the process runs Exim with the &%-bs%& option, the message is read
1020 interactively, using the SMTP protocol. A two-way pipe is normally used for
1021 passing data between the local process and the Exim process.
1022 This is &"real"& SMTP and is handled in the same way as SMTP over TCP/IP. For
1023 example, the ACLs for SMTP commands are used for this form of submission.
1024 .next
1025 A local process may also make a TCP/IP call to the host's loopback address
1026 ( or any other of its IP addresses. When receiving messages, Exim
1027 does not treat the loopback address specially. It treats all such connections
1028 in the same way as connections from other hosts.
1029 .endlist
1032 .cindex "message sender, constructed by Exim"
1033 .cindex "sender" "constructed by Exim"
1034 In the three cases that do not involve TCP/IP, the sender address is
1035 constructed from the login name of the user that called Exim and a default
1036 qualification domain (which can be set by the &%qualify_domain%& configuration
1037 option). For local or batch SMTP, a sender address that is passed using the
1038 SMTP MAIL command is ignored. However, the system administrator may allow
1039 certain users (&"trusted users"&) to specify a different sender address
1040 unconditionally, or all users to specify certain forms of different sender
1041 address. The &%-f%& option or the SMTP MAIL command is used to specify these
1042 different addresses. See section &<<SECTtrustedadmin>>& for details of trusted
1043 users, and the &%untrusted_set_sender%& option for a way of allowing untrusted
1044 users to change sender addresses.
1046 Messages received by either of the non-interactive mechanisms are subject to
1047 checking by the non-SMTP ACL, if one is defined. Messages received using SMTP
1048 (either over TCP/IP, or interacting with a local process) can be checked by a
1049 number of ACLs that operate at different times during the SMTP session. Either
1050 individual recipients, or the entire message, can be rejected if local policy
1051 requirements are not met. The &[local_scan()]& function (see chapter
1052 &<<CHAPlocalscan>>&) is run for all incoming messages.
1054 Exim can be configured not to start a delivery process when a message is
1055 received; this can be unconditional, or depend on the number of incoming SMTP
1056 connections or the system load. In these situations, new messages wait on the
1057 queue until a queue runner process picks them up. However, in standard
1058 configurations under normal conditions, delivery is started as soon as a
1059 message is received.
1065 .section "Handling an incoming message" "SECID14"
1066 .cindex "spool directory" "files that hold a message"
1067 .cindex "file" "how a message is held"
1068 When Exim accepts a message, it writes two files in its spool directory. The
1069 first contains the envelope information, the current status of the message, and
1070 the header lines, and the second contains the body of the message. The names of
1071 the two spool files consist of the message id, followed by &`-H`& for the
1072 file containing the envelope and header, and &`-D`& for the data file.
1074 .cindex "spool directory" "&_input_& sub-directory"
1075 By default all these message files are held in a single directory called
1076 &_input_& inside the general Exim spool directory. Some operating systems do
1077 not perform very well if the number of files in a directory gets large; to
1078 improve performance in such cases, the &%split_spool_directory%& option can be
1079 used. This causes Exim to split up the input files into 62 sub-directories
1080 whose names are single letters or digits. When this is done, the queue is
1081 processed one sub-directory at a time instead of all at once, which can improve
1082 overall performance even when there are not enough files in each directory to
1083 affect file system performance.
1085 The envelope information consists of the address of the message's sender and
1086 the addresses of the recipients. This information is entirely separate from
1087 any addresses contained in the header lines. The status of the message includes
1088 a list of recipients who have already received the message. The format of the
1089 first spool file is described in chapter &<<CHAPspool>>&.
1091 .cindex "rewriting" "addresses"
1092 Address rewriting that is specified in the rewrite section of the configuration
1093 (see chapter &<<CHAPrewrite>>&) is done once and for all on incoming addresses,
1094 both in the header lines and the envelope, at the time the message is accepted.
1095 If during the course of delivery additional addresses are generated (for
1096 example, via aliasing), these new addresses are rewritten as soon as they are
1097 generated. At the time a message is actually delivered (transported) further
1098 rewriting can take place; because this is a transport option, it can be
1099 different for different forms of delivery. It is also possible to specify the
1100 addition or removal of certain header lines at the time the message is
1101 delivered (see chapters &<<CHAProutergeneric>>& and
1102 &<<CHAPtransportgeneric>>&).
1106 .section "Life of a message" "SECID15"
1107 .cindex "message" "life of"
1108 .cindex "message" "frozen"
1109 A message remains in the spool directory until it is completely delivered to
1110 its recipients or to an error address, or until it is deleted by an
1111 administrator or by the user who originally created it. In cases when delivery
1112 cannot proceed &-- for example, when a message can neither be delivered to its
1113 recipients nor returned to its sender, the message is marked &"frozen"& on the
1114 spool, and no more deliveries are attempted.
1116 .cindex "frozen messages" "thawing"
1117 .cindex "message" "thawing frozen"
1118 An administrator can &"thaw"& such messages when the problem has been
1119 corrected, and can also freeze individual messages by hand if necessary. In
1120 addition, an administrator can force a delivery error, causing a bounce message
1121 to be sent.
1123 .oindex "&%timeout_frozen_after%&"
1124 .oindex "&%ignore_bounce_errors_after%&"
1125 There are options called &%ignore_bounce_errors_after%& and
1126 &%timeout_frozen_after%&, which discard frozen messages after a certain time.
1127 The first applies only to frozen bounces, the second to any frozen messages.
1129 .cindex "message" "log file for"
1130 .cindex "log" "file for each message"
1131 While Exim is working on a message, it writes information about each delivery
1132 attempt to its main log file. This includes successful, unsuccessful, and
1133 delayed deliveries for each recipient (see chapter &<<CHAPlog>>&). The log
1134 lines are also written to a separate &'message log'& file for each message.
1135 These logs are solely for the benefit of the administrator, and are normally
1136 deleted along with the spool files when processing of a message is complete.
1137 The use of individual message logs can be disabled by setting
1138 &%no_message_logs%&; this might give an improvement in performance on very busy
1139 systems.
1141 .cindex "journal file"
1142 .cindex "file" "journal"
1143 All the information Exim itself needs to set up a delivery is kept in the first
1144 spool file, along with the header lines. When a successful delivery occurs, the
1145 address is immediately written at the end of a journal file, whose name is the
1146 message id followed by &`-J`&. At the end of a delivery run, if there are some
1147 addresses left to be tried again later, the first spool file (the &`-H`& file)
1148 is updated to indicate which these are, and the journal file is then deleted.
1149 Updating the spool file is done by writing a new file and renaming it, to
1150 minimize the possibility of data loss.
1152 Should the system or the program crash after a successful delivery but before
1153 the spool file has been updated, the journal is left lying around. The next
1154 time Exim attempts to deliver the message, it reads the journal file and
1155 updates the spool file before proceeding. This minimizes the chances of double
1156 deliveries caused by crashes.
1160 .section "Processing an address for delivery" "SECTprocaddress"
1161 .cindex "drivers" "definition of"
1162 .cindex "router" "definition of"
1163 .cindex "transport" "definition of"
1164 The main delivery processing elements of Exim are called &'routers'& and
1165 &'transports'&, and collectively these are known as &'drivers'&. Code for a
1166 number of them is provided in the source distribution, and compile-time options
1167 specify which ones are included in the binary. Run time options specify which
1168 ones are actually used for delivering messages.
1170 .cindex "drivers" "instance definition"
1171 Each driver that is specified in the run time configuration is an &'instance'&
1172 of that particular driver type. Multiple instances are allowed; for example,
1173 you can set up several different &(smtp)& transports, each with different
1174 option values that might specify different ports or different timeouts. Each
1175 instance has its own identifying name. In what follows we will normally use the
1176 instance name when discussing one particular instance (that is, one specific
1177 configuration of the driver), and the generic driver name when discussing
1178 the driver's features in general.
1180 A &'router'& is a driver that operates on an address, either determining how
1181 its delivery should happen, by assigning it to a specific transport, or
1182 converting the address into one or more new addresses (for example, via an
1183 alias file). A router may also explicitly choose to fail an address, causing it
1184 to be bounced.
1186 A &'transport'& is a driver that transmits a copy of the message from Exim's
1187 spool to some destination. There are two kinds of transport: for a &'local'&
1188 transport, the destination is a file or a pipe on the local host, whereas for a
1189 &'remote'& transport the destination is some other host. A message is passed
1190 to a specific transport as a result of successful routing. If a message has
1191 several recipients, it may be passed to a number of different transports.
1193 .cindex "preconditions" "definition of"
1194 An address is processed by passing it to each configured router instance in
1195 turn, subject to certain preconditions, until a router accepts the address or
1196 specifies that it should be bounced. We will describe this process in more
1197 detail shortly. First, as a simple example, we consider how each recipient
1198 address in a message is processed in a small configuration of three routers.
1200 To make this a more concrete example, it is described in terms of some actual
1201 routers, but remember, this is only an example. You can configure Exim's
1202 routers in many different ways, and there may be any number of routers in a
1203 configuration.
1205 The first router that is specified in a configuration is often one that handles
1206 addresses in domains that are not recognized specially by the local host. These
1207 are typically addresses for arbitrary domains on the Internet. A precondition
1208 is set up which looks for the special domains known to the host (for example,
1209 its own domain name), and the router is run for addresses that do &'not'&
1210 match. Typically, this is a router that looks up domains in the DNS in order to
1211 find the hosts to which this address routes. If it succeeds, the address is
1212 assigned to a suitable SMTP transport; if it does not succeed, the router is
1213 configured to fail the address.
1215 The second router is reached only when the domain is recognized as one that
1216 &"belongs"& to the local host. This router does redirection &-- also known as
1217 aliasing and forwarding. When it generates one or more new addresses from the
1218 original, each of them is routed independently from the start. Otherwise, the
1219 router may cause an address to fail, or it may simply decline to handle the
1220 address, in which case the address is passed to the next router.
1222 The final router in many configurations is one that checks to see if the
1223 address belongs to a local mailbox. The precondition may involve a check to
1224 see if the local part is the name of a login account, or it may look up the
1225 local part in a file or a database. If its preconditions are not met, or if
1226 the router declines, we have reached the end of the routers. When this happens,
1227 the address is bounced.
1231 .section "Processing an address for verification" "SECID16"
1232 .cindex "router" "for verification"
1233 .cindex "verifying address" "overview"
1234 As well as being used to decide how to deliver to an address, Exim's routers
1235 are also used for &'address verification'&. Verification can be requested as
1236 one of the checks to be performed in an ACL for incoming messages, on both
1237 sender and recipient addresses, and it can be tested using the &%-bv%& and
1238 &%-bvs%& command line options.
1240 When an address is being verified, the routers are run in &"verify mode"&. This
1241 does not affect the way the routers work, but it is a state that can be
1242 detected. By this means, a router can be skipped or made to behave differently
1243 when verifying. A common example is a configuration in which the first router
1244 sends all messages to a message-scanning program, unless they have been
1245 previously scanned. Thus, the first router accepts all addresses without any
1246 checking, making it useless for verifying. Normally, the &%no_verify%& option
1247 would be set for such a router, causing it to be skipped in verify mode.
1252 .section "Running an individual router" "SECTrunindrou"
1253 .cindex "router" "running details"
1254 .cindex "preconditions" "checking"
1255 .cindex "router" "result of running"
1256 As explained in the example above, a number of preconditions are checked before
1257 running a router. If any are not met, the router is skipped, and the address is
1258 passed to the next router. When all the preconditions on a router &'are'& met,
1259 the router is run. What happens next depends on the outcome, which is one of
1260 the following:
1262 .ilist
1263 &'accept'&: The router accepts the address, and either assigns it to a
1264 transport, or generates one or more &"child"& addresses. Processing the
1265 original address ceases,
1266 .oindex "&%unseen%&"
1267 unless the &%unseen%& option is set on the router. This option
1268 can be used to set up multiple deliveries with different routing (for example,
1269 for keeping archive copies of messages). When &%unseen%& is set, the address is
1270 passed to the next router. Normally, however, an &'accept'& return marks the
1271 end of routing.
1273 Any child addresses generated by the router are processed independently,
1274 starting with the first router by default. It is possible to change this by
1275 setting the &%redirect_router%& option to specify which router to start at for
1276 child addresses. Unlike &%pass_router%& (see below) the router specified by
1277 &%redirect_router%& may be anywhere in the router configuration.
1278 .next
1279 &'pass'&: The router recognizes the address, but cannot handle it itself. It
1280 requests that the address be passed to another router. By default the address
1281 is passed to the next router, but this can be changed by setting the
1282 &%pass_router%& option. However, (unlike &%redirect_router%&) the named router
1283 must be below the current router (to avoid loops).
1284 .next
1285 &'decline'&: The router declines to accept the address because it does not
1286 recognize it at all. By default, the address is passed to the next router, but
1287 this can be prevented by setting the &%no_more%& option. When &%no_more%& is
1288 set, all the remaining routers are skipped. In effect, &%no_more%& converts
1289 &'decline'& into &'fail'&.
1290 .next
1291 &'fail'&: The router determines that the address should fail, and queues it for
1292 the generation of a bounce message. There is no further processing of the
1293 original address unless &%unseen%& is set on the router.
1294 .next
1295 &'defer'&: The router cannot handle the address at the present time. (A
1296 database may be offline, or a DNS lookup may have timed out.) No further
1297 processing of the address happens in this delivery attempt. It is tried again
1298 next time the message is considered for delivery.
1299 .next
1300 &'error'&: There is some error in the router (for example, a syntax error in
1301 its configuration). The action is as for defer.
1302 .endlist
1304 If an address reaches the end of the routers without having been accepted by
1305 any of them, it is bounced as unrouteable. The default error message in this
1306 situation is &"unrouteable address"&, but you can set your own message by
1307 making use of the &%cannot_route_message%& option. This can be set for any
1308 router; the value from the last router that &"saw"& the address is used.
1310 Sometimes while routing you want to fail a delivery when some conditions are
1311 met but others are not, instead of passing the address on for further routing.
1312 You can do this by having a second router that explicitly fails the delivery
1313 when the relevant conditions are met. The &(redirect)& router has a &"fail"&
1314 facility for this purpose.
1317 .section "Duplicate addresses" "SECID17"
1318 .cindex "case of local parts"
1319 .cindex "address duplicate, discarding"
1320 .cindex "duplicate addresses"
1321 Once routing is complete, Exim scans the addresses that are assigned to local
1322 and remote transports, and discards any duplicates that it finds. During this
1323 check, local parts are treated as case-sensitive. This happens only when
1324 actually delivering a message; when testing routers with &%-bt%&, all the
1325 routed addresses are shown.
1329 .section "Router preconditions" "SECTrouprecon"
1330 .cindex "router" "preconditions, order of processing"
1331 .cindex "preconditions" "order of processing"
1332 The preconditions that are tested for each router are listed below, in the
1333 order in which they are tested. The individual configuration options are
1334 described in more detail in chapter &<<CHAProutergeneric>>&.
1336 .ilist
1337 The &%local_part_prefix%& and &%local_part_suffix%& options can specify that
1338 the local parts handled by the router may or must have certain prefixes and/or
1339 suffixes. If a mandatory affix (prefix or suffix) is not present, the router is
1340 skipped. These conditions are tested first. When an affix is present, it is
1341 removed from the local part before further processing, including the evaluation
1342 of any other conditions.
1343 .next
1344 Routers can be designated for use only when not verifying an address, that is,
1345 only when routing it for delivery (or testing its delivery routing). If the
1346 &%verify%& option is set false, the router is skipped when Exim is verifying an
1347 address.
1348 Setting the &%verify%& option actually sets two options, &%verify_sender%& and
1349 &%verify_recipient%&, which independently control the use of the router for
1350 sender and recipient verification. You can set these options directly if
1351 you want a router to be used for only one type of verification.
1352 .next
1353 If the &%address_test%& option is set false, the router is skipped when Exim is
1354 run with the &%-bt%& option to test an address routing. This can be helpful
1355 when the first router sends all new messages to a scanner of some sort; it
1356 makes it possible to use &%-bt%& to test subsequent delivery routing without
1357 having to simulate the effect of the scanner.
1358 .next
1359 Routers can be designated for use only when verifying an address, as
1360 opposed to routing it for delivery. The &%verify_only%& option controls this.
1361 .next
1362 Individual routers can be explicitly skipped when running the routers to
1363 check an address given in the SMTP EXPN command (see the &%expn%& option).
1364 .next
1365 If the &%domains%& option is set, the domain of the address must be in the set
1366 of domains that it defines.
1367 .next
1368 .vindex "&$local_part_prefix$&"
1369 .vindex "&$local_part$&"
1370 .vindex "&$local_part_suffix$&"
1371 If the &%local_parts%& option is set, the local part of the address must be in
1372 the set of local parts that it defines. If &%local_part_prefix%& or
1373 &%local_part_suffix%& is in use, the prefix or suffix is removed from the local
1374 part before this check. If you want to do precondition tests on local parts
1375 that include affixes, you can do so by using a &%condition%& option (see below)
1376 that uses the variables &$local_part$&, &$local_part_prefix$&, and
1377 &$local_part_suffix$& as necessary.
1378 .next
1379 .vindex "&$local_user_uid$&"
1380 .vindex "&$local_user_gid$&"
1381 .vindex "&$home$&"
1382 If the &%check_local_user%& option is set, the local part must be the name of
1383 an account on the local host. If this check succeeds, the uid and gid of the
1384 local user are placed in &$local_user_uid$& and &$local_user_gid$& and the
1385 user's home directory is placed in &$home$&; these values can be used in the
1386 remaining preconditions.
1387 .next
1388 If the &%router_home_directory%& option is set, it is expanded at this point,
1389 because it overrides the value of &$home$&. If this expansion were left till
1390 later, the value of &$home$& as set by &%check_local_user%& would be used in
1391 subsequent tests. Having two different values of &$home$& in the same router
1392 could lead to confusion.
1393 .next
1394 If the &%senders%& option is set, the envelope sender address must be in the
1395 set of addresses that it defines.
1396 .next
1397 If the &%require_files%& option is set, the existence or non-existence of
1398 specified files is tested.
1399 .next
1400 .cindex "customizing" "precondition"
1401 If the &%condition%& option is set, it is evaluated and tested. This option
1402 uses an expanded string to allow you to set up your own custom preconditions.
1403 Expanded strings are described in chapter &<<CHAPexpand>>&.
1404 .endlist
1407 Note that &%require_files%& comes near the end of the list, so you cannot use
1408 it to check for the existence of a file in which to lookup up a domain, local
1409 part, or sender. However, as these options are all expanded, you can use the
1410 &%exists%& expansion condition to make such tests within each condition. The
1411 &%require_files%& option is intended for checking files that the router may be
1412 going to use internally, or which are needed by a specific transport (for
1413 example, &_.procmailrc_&).
1417 .section "Delivery in detail" "SECID18"
1418 .cindex "delivery" "in detail"
1419 When a message is to be delivered, the sequence of events is as follows:
1421 .ilist
1422 If a system-wide filter file is specified, the message is passed to it. The
1423 filter may add recipients to the message, replace the recipients, discard the
1424 message, cause a new message to be generated, or cause the message delivery to
1425 fail. The format of the system filter file is the same as for Exim user filter
1426 files, described in the separate document entitled &'Exim's interfaces to mail
1427 filtering'&.
1428 .cindex "Sieve filter" "not available for system filter"
1429 (&*Note*&: Sieve cannot be used for system filter files.)
1431 Some additional features are available in system filters &-- see chapter
1432 &<<CHAPsystemfilter>>& for details. Note that a message is passed to the system
1433 filter only once per delivery attempt, however many recipients it has. However,
1434 if there are several delivery attempts because one or more addresses could not
1435 be immediately delivered, the system filter is run each time. The filter
1436 condition &%first_delivery%& can be used to detect the first run of the system
1437 filter.
1438 .next
1439 Each recipient address is offered to each configured router in turn, subject to
1440 its preconditions, until one is able to handle it. If no router can handle the
1441 address, that is, if they all decline, the address is failed. Because routers
1442 can be targeted at particular domains, several locally handled domains can be
1443 processed entirely independently of each other.
1444 .next
1445 .cindex "routing" "loops in"
1446 .cindex "loop" "while routing"
1447 A router that accepts an address may assign it to a local or a remote
1448 transport. However, the transport is not run at this time. Instead, the address
1449 is placed on a list for the particular transport, which will be run later.
1450 Alternatively, the router may generate one or more new addresses (typically
1451 from alias, forward, or filter files). New addresses are fed back into this
1452 process from the top, but in order to avoid loops, a router ignores any address
1453 which has an identically-named ancestor that was processed by itself.
1454 .next
1455 When all the routing has been done, addresses that have been successfully
1456 handled are passed to their assigned transports. When local transports are
1457 doing real local deliveries, they handle only one address at a time, but if a
1458 local transport is being used as a pseudo-remote transport (for example, to
1459 collect batched SMTP messages for transmission by some other means) multiple
1460 addresses can be handled. Remote transports can always handle more than one
1461 address at a time, but can be configured not to do so, or to restrict multiple
1462 addresses to the same domain.
1463 .next
1464 Each local delivery to a file or a pipe runs in a separate process under a
1465 non-privileged uid, and these deliveries are run one at a time. Remote
1466 deliveries also run in separate processes, normally under a uid that is private
1467 to Exim (&"the Exim user"&), but in this case, several remote deliveries can be
1468 run in parallel. The maximum number of simultaneous remote deliveries for any
1469 one message is set by the &%remote_max_parallel%& option.
1470 The order in which deliveries are done is not defined, except that all local
1471 deliveries happen before any remote deliveries.
1472 .next
1473 .cindex "queue runner"
1474 When it encounters a local delivery during a queue run, Exim checks its retry
1475 database to see if there has been a previous temporary delivery failure for the
1476 address before running the local transport. If there was a previous failure,
1477 Exim does not attempt a new delivery until the retry time for the address is
1478 reached. However, this happens only for delivery attempts that are part of a
1479 queue run. Local deliveries are always attempted when delivery immediately
1480 follows message reception, even if retry times are set for them. This makes for
1481 better behaviour if one particular message is causing problems (for example,
1482 causing quota overflow, or provoking an error in a filter file).
1483 .next
1484 .cindex "delivery" "retry in remote transports"
1485 Remote transports do their own retry handling, since an address may be
1486 deliverable to one of a number of hosts, each of which may have a different
1487 retry time. If there have been previous temporary failures and no host has
1488 reached its retry time, no delivery is attempted, whether in a queue run or
1489 not. See chapter &<<CHAPretry>>& for details of retry strategies.
1490 .next
1491 If there were any permanent errors, a bounce message is returned to an
1492 appropriate address (the sender in the common case), with details of the error
1493 for each failing address. Exim can be configured to send copies of bounce
1494 messages to other addresses.
1495 .next
1496 .cindex "delivery" "deferral"
1497 If one or more addresses suffered a temporary failure, the message is left on
1498 the queue, to be tried again later. Delivery of these addresses is said to be
1499 &'deferred'&.
1500 .next
1501 When all the recipient addresses have either been delivered or bounced,
1502 handling of the message is complete. The spool files and message log are
1503 deleted, though the message log can optionally be preserved if required.
1504 .endlist
1509 .section "Retry mechanism" "SECID19"
1510 .cindex "delivery" "retry mechanism"
1511 .cindex "retry" "description of mechanism"
1512 .cindex "queue runner"
1513 Exim's mechanism for retrying messages that fail to get delivered at the first
1514 attempt is the queue runner process. You must either run an Exim daemon that
1515 uses the &%-q%& option with a time interval to start queue runners at regular
1516 intervals, or use some other means (such as &'cron'&) to start them. If you do
1517 not arrange for queue runners to be run, messages that fail temporarily at the
1518 first attempt will remain on your queue for ever. A queue runner process works
1519 its way through the queue, one message at a time, trying each delivery that has
1520 passed its retry time.
1521 You can run several queue runners at once.
1523 Exim uses a set of configured rules to determine when next to retry the failing
1524 address (see chapter &<<CHAPretry>>&). These rules also specify when Exim
1525 should give up trying to deliver to the address, at which point it generates a
1526 bounce message. If no retry rules are set for a particular host, address, and
1527 error combination, no retries are attempted, and temporary errors are treated
1528 as permanent.
1532 .section "Temporary delivery failure" "SECID20"
1533 .cindex "delivery" "temporary failure"
1534 There are many reasons why a message may not be immediately deliverable to a
1535 particular address. Failure to connect to a remote machine (because it, or the
1536 connection to it, is down) is one of the most common. Temporary failures may be
1537 detected during routing as well as during the transport stage of delivery.
1538 Local deliveries may be delayed if NFS files are unavailable, or if a mailbox
1539 is on a file system where the user is over quota. Exim can be configured to
1540 impose its own quotas on local mailboxes; where system quotas are set they will
1541 also apply.
1543 If a host is unreachable for a period of time, a number of messages may be
1544 waiting for it by the time it recovers, and sending them in a single SMTP
1545 connection is clearly beneficial. Whenever a delivery to a remote host is
1546 deferred,
1548 .cindex "hints database"
1549 Exim makes a note in its hints database, and whenever a successful
1550 SMTP delivery has happened, it looks to see if any other messages are waiting
1551 for the same host. If any are found, they are sent over the same SMTP
1552 connection, subject to a configuration limit as to the maximum number in any
1553 one connection.
1558 .section "Permanent delivery failure" "SECID21"
1559 .cindex "delivery" "permanent failure"
1560 .cindex "bounce message" "when generated"
1561 When a message cannot be delivered to some or all of its intended recipients, a
1562 bounce message is generated. Temporary delivery failures turn into permanent
1563 errors when their timeout expires. All the addresses that fail in a given
1564 delivery attempt are listed in a single message. If the original message has
1565 many recipients, it is possible for some addresses to fail in one delivery
1566 attempt and others to fail subsequently, giving rise to more than one bounce
1567 message. The wording of bounce messages can be customized by the administrator.
1568 See chapter &<<CHAPemsgcust>>& for details.
1570 .cindex "&'X-Failed-Recipients:'& header line"
1571 Bounce messages contain an &'X-Failed-Recipients:'& header line that lists the
1572 failed addresses, for the benefit of programs that try to analyse such messages
1573 automatically.
1575 .cindex "bounce message" "recipient of"
1576 A bounce message is normally sent to the sender of the original message, as
1577 obtained from the message's envelope. For incoming SMTP messages, this is the
1578 address given in the MAIL command. However, when an address is expanded via a
1579 forward or alias file, an alternative address can be specified for delivery
1580 failures of the generated addresses. For a mailing list expansion (see section
1581 &<<SECTmailinglists>>&) it is common to direct bounce messages to the manager
1582 of the list.
1586 .section "Failures to deliver bounce messages" "SECID22"
1587 .cindex "bounce message" "failure to deliver"
1588 If a bounce message (either locally generated or received from a remote host)
1589 itself suffers a permanent delivery failure, the message is left on the queue,
1590 but it is frozen, awaiting the attention of an administrator. There are options
1591 that can be used to make Exim discard such failed messages, or to keep them
1592 for only a short time (see &%timeout_frozen_after%& and
1593 &%ignore_bounce_errors_after%&).
1599 . ////////////////////////////////////////////////////////////////////////////
1600 . ////////////////////////////////////////////////////////////////////////////
1602 .chapter "Building and installing Exim" "CHID3"
1603 .scindex IIDbuex "building Exim"
1605 .section "Unpacking" "SECID23"
1606 Exim is distributed as a gzipped or bzipped tar file which, when unpacked,
1607 creates a directory with the name of the current release (for example,
1608 &_exim-&version;_&) into which the following files are placed:
1610 .table2 140pt
1611 .irow &_ACKNOWLEDGMENTS_& "contains some acknowledgments"
1612 .irow &_CHANGES_& "contains a reference to where changes are &&&
1613 documented"
1614 .irow &_LICENCE_& "the GNU General Public Licence"
1615 .irow &_Makefile_& "top-level make file"
1616 .irow &_NOTICE_& "conditions for the use of Exim"
1617 .irow &_README_& "list of files, directories and simple build &&&
1618 instructions"
1619 .endtable
1621 Other files whose names begin with &_README_& may also be present. The
1622 following subdirectories are created:
1624 .table2 140pt
1625 .irow &_Local_& "an empty directory for local configuration files"
1626 .irow &_OS_& "OS-specific files"
1627 .irow &_doc_& "documentation files"
1628 .irow &_exim_monitor_& "source files for the Exim monitor"
1629 .irow &_scripts_& "scripts used in the build process"
1630 .irow &_src_& "remaining source files"
1631 .irow &_util_& "independent utilities"
1632 .endtable
1634 The main utility programs are contained in the &_src_& directory, and are built
1635 with the Exim binary. The &_util_& directory contains a few optional scripts
1636 that may be useful to some sites.
1639 .section "Multiple machine architectures and operating systems" "SECID24"
1640 .cindex "building Exim" "multiple OS/architectures"
1641 The building process for Exim is arranged to make it easy to build binaries for
1642 a number of different architectures and operating systems from the same set of
1643 source files. Compilation does not take place in the &_src_& directory.
1644 Instead, a &'build directory'& is created for each architecture and operating
1645 system.
1646 .cindex "symbolic link" "to build directory"
1647 Symbolic links to the sources are installed in this directory, which is where
1648 the actual building takes place. In most cases, Exim can discover the machine
1649 architecture and operating system for itself, but the defaults can be
1650 overridden if necessary.
1653 .section "PCRE library" "SECTpcre"
1654 .cindex "PCRE library"
1655 Exim no longer has an embedded PCRE library as the vast majority of
1656 modern systems include PCRE as a system library, although you may need
1657 to install the PCRE or PCRE development package for your operating
1658 system. If your system has a normal PCRE installation the Exim build
1659 process will need no further configuration. If the library or the
1660 headers are in an unusual location you will need to set the PCRE_LIBS
1661 and INCLUDE directives appropriately. If your operating system has no
1662 PCRE support then you will need to obtain and build the current PCRE
1663 from &url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/).
1665 .section "DBM libraries" "SECTdb"
1666 .cindex "DBM libraries" "discussion of"
1667 .cindex "hints database" "DBM files used for"
1668 Even if you do not use any DBM files in your configuration, Exim still needs a
1669 DBM library in order to operate, because it uses indexed files for its hints
1670 databases. Unfortunately, there are a number of DBM libraries in existence, and
1671 different operating systems often have different ones installed.
1673 .cindex "Solaris" "DBM library for"
1674 .cindex "IRIX, DBM library for"
1675 .cindex "BSD, DBM library for"
1676 .cindex "Linux, DBM library for"
1677 If you are using Solaris, IRIX, one of the modern BSD systems, or a modern
1678 Linux distribution, the DBM configuration should happen automatically, and you
1679 may be able to ignore this section. Otherwise, you may have to learn more than
1680 you would like about DBM libraries from what follows.
1682 .cindex "&'ndbm'& DBM library"
1683 Licensed versions of Unix normally contain a library of DBM functions operating
1684 via the &'ndbm'& interface, and this is what Exim expects by default. Free
1685 versions of Unix seem to vary in what they contain as standard. In particular,
1686 some early versions of Linux have no default DBM library, and different
1687 distributors have chosen to bundle different libraries with their packaged
1688 versions. However, the more recent releases seem to have standardized on the
1689 Berkeley DB library.
1691 Different DBM libraries have different conventions for naming the files they
1692 use. When a program opens a file called &_dbmfile_&, there are several
1693 possibilities:
1695 .olist
1696 A traditional &'ndbm'& implementation, such as that supplied as part of
1697 Solaris, operates on two files called &_dbmfile.dir_& and &_dbmfile.pag_&.
1698 .next
1699 .cindex "&'gdbm'& DBM library"
1700 The GNU library, &'gdbm'&, operates on a single file. If used via its &'ndbm'&
1701 compatibility interface it makes two different hard links to it with names
1702 &_dbmfile.dir_& and &_dbmfile.pag_&, but if used via its native interface, the
1703 file name is used unmodified.
1704 .next
1705 .cindex "Berkeley DB library"
1706 The Berkeley DB package, if called via its &'ndbm'& compatibility interface,
1707 operates on a single file called &_dbmfile.db_&, but otherwise looks to the
1708 programmer exactly the same as the traditional &'ndbm'& implementation.
1709 .next
1710 If the Berkeley package is used in its native mode, it operates on a single
1711 file called &_dbmfile_&; the programmer's interface is somewhat different to
1712 the traditional &'ndbm'& interface.
1713 .next
1714 To complicate things further, there are several very different versions of the
1715 Berkeley DB package. Version 1.85 was stable for a very long time, releases
1716 2.&'x'& and 3.&'x'& were current for a while, but the latest versions are now
1717 numbered 4.&'x'&. Maintenance of some of the earlier releases has ceased. All
1718 versions of Berkeley DB can be obtained from
1719 &url(http://www.sleepycat.com/).
1720 .next
1721 .cindex "&'tdb'& DBM library"
1722 Yet another DBM library, called &'tdb'&, is available from
1723 &url(http://download.sourceforge.net/tdb). It has its own interface, and also
1724 operates on a single file.
1725 .endlist
1727 .cindex "USE_DB"
1728 .cindex "DBM libraries" "configuration for building"
1729 Exim and its utilities can be compiled to use any of these interfaces. In order
1730 to use any version of the Berkeley DB package in native mode, you must set
1731 USE_DB in an appropriate configuration file (typically
1732 &_Local/Makefile_&). For example:
1733 .code
1734 USE_DB=yes
1735 .endd
1736 Similarly, for gdbm you set USE_GDBM, and for tdb you set USE_TDB. An
1737 error is diagnosed if you set more than one of these.
1739 At the lowest level, the build-time configuration sets none of these options,
1740 thereby assuming an interface of type (1). However, some operating system
1741 configuration files (for example, those for the BSD operating systems and
1742 Linux) assume type (4) by setting USE_DB as their default, and the
1743 configuration files for Cygwin set USE_GDBM. Anything you set in
1744 &_Local/Makefile_&, however, overrides these system defaults.
1746 As well as setting USE_DB, USE_GDBM, or USE_TDB, it may also be
1747 necessary to set DBMLIB, to cause inclusion of the appropriate library, as
1748 in one of these lines:
1749 .code
1750 DBMLIB = -ldb
1751 DBMLIB = -ltdb
1752 .endd
1753 Settings like that will work if the DBM library is installed in the standard
1754 place. Sometimes it is not, and the library's header file may also not be in
1755 the default path. You may need to set INCLUDE to specify where the header
1756 file is, and to specify the path to the library more fully in DBMLIB, as in
1757 this example:
1758 .code
1759 INCLUDE=-I/usr/local/include/db-4.1
1760 DBMLIB=/usr/local/lib/db-4.1/libdb.a
1761 .endd
1762 There is further detailed discussion about the various DBM libraries in the
1763 file &_doc/dbm.discuss.txt_& in the Exim distribution.
1767 .section "Pre-building configuration" "SECID25"
1768 .cindex "building Exim" "pre-building configuration"
1769 .cindex "configuration for building Exim"
1770 .cindex "&_Local/Makefile_&"
1771 .cindex "&_src/EDITME_&"
1772 Before building Exim, a local configuration file that specifies options
1773 independent of any operating system has to be created with the name
1774 &_Local/Makefile_&. A template for this file is supplied as the file
1775 &_src/EDITME_&, and it contains full descriptions of all the option settings
1776 therein. These descriptions are therefore not repeated here. If you are
1777 building Exim for the first time, the simplest thing to do is to copy
1778 &_src/EDITME_& to &_Local/Makefile_&, then read it and edit it appropriately.
1780 There are three settings that you must supply, because Exim will not build
1781 without them. They are the location of the run time configuration file
1782 (CONFIGURE_FILE), the directory in which Exim binaries will be installed
1783 (BIN_DIRECTORY), and the identity of the Exim user (EXIM_USER and
1784 maybe EXIM_GROUP as well). The value of CONFIGURE_FILE can in fact be
1785 a colon-separated list of file names; Exim uses the first of them that exists.
1787 There are a few other parameters that can be specified either at build time or
1788 at run time, to enable the same binary to be used on a number of different
1789 machines. However, if the locations of Exim's spool directory and log file
1790 directory (if not within the spool directory) are fixed, it is recommended that
1791 you specify them in &_Local/Makefile_& instead of at run time, so that errors
1792 detected early in Exim's execution (such as a malformed configuration file) can
1793 be logged.
1795 .cindex "content scanning" "specifying at build time"
1796 Exim's interfaces for calling virus and spam scanning software directly from
1797 access control lists are not compiled by default. If you want to include these
1798 facilities, you need to set
1799 .code
1801 .endd
1802 in your &_Local/Makefile_&. For details of the facilities themselves, see
1803 chapter &<<CHAPexiscan>>&.
1806 .cindex "&_Local/eximon.conf_&"
1807 .cindex "&_exim_monitor/EDITME_&"
1808 If you are going to build the Exim monitor, a similar configuration process is
1809 required. The file &_exim_monitor/EDITME_& must be edited appropriately for
1810 your installation and saved under the name &_Local/eximon.conf_&. If you are
1811 happy with the default settings described in &_exim_monitor/EDITME_&,
1812 &_Local/eximon.conf_& can be empty, but it must exist.
1814 This is all the configuration that is needed in straightforward cases for known
1815 operating systems. However, the building process is set up so that it is easy
1816 to override options that are set by default or by operating-system-specific
1817 configuration files, for example to change the name of the C compiler, which
1818 defaults to &%gcc%&. See section &<<SECToverride>>& below for details of how to
1819 do this.
1823 .section "Support for iconv()" "SECID26"
1824 .cindex "&[iconv()]& support"
1825 .cindex "RFC 2047"
1826 The contents of header lines in messages may be encoded according to the rules
1827 described RFC 2047. This makes it possible to transmit characters that are not
1828 in the ASCII character set, and to label them as being in a particular
1829 character set. When Exim is inspecting header lines by means of the &%$h_%&
1830 mechanism, it decodes them, and translates them into a specified character set
1831 (default ISO-8859-1). The translation is possible only if the operating system
1832 supports the &[iconv()]& function.
1834 However, some of the operating systems that supply &[iconv()]& do not support
1835 very many conversions. The GNU &%libiconv%& library (available from
1836 &url(http://www.gnu.org/software/libiconv/)) can be installed on such
1837 systems to remedy this deficiency, as well as on systems that do not supply
1838 &[iconv()]& at all. After installing &%libiconv%&, you should add
1839 .code
1840 HAVE_ICONV=yes
1841 .endd
1842 to your &_Local/Makefile_& and rebuild Exim.
1846 .section "Including TLS/SSL encryption support" "SECTinctlsssl"
1847 .cindex "TLS" "including support for TLS"
1848 .cindex "encryption" "including support for"
1849 .cindex "SUPPORT_TLS"
1850 .cindex "OpenSSL" "building Exim with"
1851 .cindex "GnuTLS" "building Exim with"
1852 Exim can be built to support encrypted SMTP connections, using the STARTTLS
1853 command as per RFC 2487. It can also support legacy clients that expect to
1854 start a TLS session immediately on connection to a non-standard port (see the
1855 &%tls_on_connect_ports%& runtime option and the &%-tls-on-connect%& command
1856 line option).
1858 If you want to build Exim with TLS support, you must first install either the
1859 OpenSSL or GnuTLS library. There is no cryptographic code in Exim itself for
1860 implementing SSL.
1862 If OpenSSL is installed, you should set
1863 .code
1864 SUPPORT_TLS=yes
1865 TLS_LIBS=-lssl -lcrypto
1866 .endd
1867 in &_Local/Makefile_&. You may also need to specify the locations of the
1868 OpenSSL library and include files. For example:
1869 .code
1870 SUPPORT_TLS=yes
1871 TLS_LIBS=-L/usr/local/openssl/lib -lssl -lcrypto
1872 TLS_INCLUDE=-I/usr/local/openssl/include/
1873 .endd
1874 .cindex "USE_GNUTLS"
1875 If GnuTLS is installed, you should set
1876 .code
1877 SUPPORT_TLS=yes
1878 USE_GNUTLS=yes
1879 TLS_LIBS=-lgnutls -ltasn1 -lgcrypt
1880 .endd
1881 in &_Local/Makefile_&, and again you may need to specify the locations of the
1882 library and include files. For example:
1883 .code
1884 SUPPORT_TLS=yes
1885 USE_GNUTLS=yes
1886 TLS_LIBS=-L/usr/gnu/lib -lgnutls -ltasn1 -lgcrypt
1887 TLS_INCLUDE=-I/usr/gnu/include
1888 .endd
1889 You do not need to set TLS_INCLUDE if the relevant directory is already
1890 specified in INCLUDE. Details of how to configure Exim to make use of TLS are
1891 given in chapter &<<CHAPTLS>>&.
1896 .section "Use of tcpwrappers" "SECID27"
1897 .cindex "tcpwrappers, building Exim to support"
1898 .cindex "USE_TCP_WRAPPERS"
1899 Exim can be linked with the &'tcpwrappers'& library in order to check incoming
1900 SMTP calls using the &'tcpwrappers'& control files. This may be a convenient
1901 alternative to Exim's own checking facilities for installations that are
1902 already making use of &'tcpwrappers'& for other purposes. To do this, you
1903 should set USE_TCP_WRAPPERS in &_Local/Makefile_&, arrange for the file
1904 &_tcpd.h_& to be available at compile time, and also ensure that the library
1905 &_libwrap.a_& is available at link time, typically by including &%-lwrap%& in
1906 EXTRALIBS_EXIM. For example, if &'tcpwrappers'& is installed in &_/usr/local_&,
1907 you might have
1908 .code
1910 CFLAGS=-O -I/usr/local/include
1911 EXTRALIBS_EXIM=-L/usr/local/lib -lwrap
1912 .endd
1913 in &_Local/Makefile_&. The name to use in the &'tcpwrappers'& control files is
1914 &"exim"&. For example, the line
1915 .code
1916 exim : LOCAL 192.168.1. .friendly.domain.example
1917 .endd
1918 in your &_/etc/hosts.allow_& file allows connections from the local host, from
1919 the subnet, and from all hosts in &'friendly.domain.example'&.
1920 All other connections are denied. Consult the &'tcpwrappers'& documentation for
1921 further details.
1925 .section "Including support for IPv6" "SECID28"
1926 .cindex "IPv6" "including support for"
1927 Exim contains code for use on systems that have IPv6 support. Setting
1928 &`HAVE_IPV6=YES`& in &_Local/Makefile_& causes the IPv6 code to be included;
1929 it may also be necessary to set IPV6_INCLUDE and IPV6_LIBS on systems
1930 where the IPv6 support is not fully integrated into the normal include and
1931 library files.
1933 Two different types of DNS record for handling IPv6 addresses have been
1934 defined. AAAA records (analogous to A records for IPv4) are in use, and are
1935 currently seen as the mainstream. Another record type called A6 was proposed
1936 as better than AAAA because it had more flexibility. However, it was felt to be
1937 over-complex, and its status was reduced to &"experimental"&. It is not known
1938 if anyone is actually using A6 records. Exim has support for A6 records, but
1939 this is included only if you set &`SUPPORT_A6=YES`& in &_Local/Makefile_&. The
1940 support has not been tested for some time.
1944 .section "The building process" "SECID29"
1945 .cindex "build directory"
1946 Once &_Local/Makefile_& (and &_Local/eximon.conf_&, if required) have been
1947 created, run &'make'& at the top level. It determines the architecture and
1948 operating system types, and creates a build directory if one does not exist.
1949 For example, on a Sun system running Solaris 8, the directory
1950 &_build-SunOS5-5.8-sparc_& is created.
1951 .cindex "symbolic link" "to source files"
1952 Symbolic links to relevant source files are installed in the build directory.
1954 &*Warning*&: The &%-j%& (parallel) flag must not be used with &'make'&; the
1955 building process fails if it is set.
1957 If this is the first time &'make'& has been run, it calls a script that builds
1958 a make file inside the build directory, using the configuration files from the
1959 &_Local_& directory. The new make file is then passed to another instance of
1960 &'make'&. This does the real work, building a number of utility scripts, and
1961 then compiling and linking the binaries for the Exim monitor (if configured), a
1962 number of utility programs, and finally Exim itself. The command &`make
1963 makefile`& can be used to force a rebuild of the make file in the build
1964 directory, should this ever be necessary.
1966 If you have problems building Exim, check for any comments there may be in the
1967 &_README_& file concerning your operating system, and also take a look at the
1968 FAQ, where some common problems are covered.
1972 .section 'Output from &"make"&' "SECID283"
1973 The output produced by the &'make'& process for compile lines is often very
1974 unreadable, because these lines can be very long. For this reason, the normal
1975 output is suppressed by default, and instead output similar to that which
1976 appears when compiling the 2.6 Linux kernel is generated: just a short line for
1977 each module that is being compiled or linked. However, it is still possible to
1978 get the full output, by calling &'make'& like this:
1979 .code
1980 FULLECHO='' make -e
1981 .endd
1982 The value of FULLECHO defaults to &"@"&, the flag character that suppresses
1983 command reflection in &'make'&. When you ask for the full output, it is
1984 given in addition to the short output.
1988 .section "Overriding build-time options for Exim" "SECToverride"
1989 .cindex "build-time options, overriding"
1990 The main make file that is created at the beginning of the building process
1991 consists of the concatenation of a number of files which set configuration
1992 values, followed by a fixed set of &'make'& instructions. If a value is set
1993 more than once, the last setting overrides any previous ones. This provides a
1994 convenient way of overriding defaults. The files that are concatenated are, in
1995 order:
1996 .display
1997 &_OS/Makefile-Default_&
1998 &_OS/Makefile-_&<&'ostype'&>
1999 &_Local/Makefile_&
2000 &_Local/Makefile-_&<&'ostype'&>
2001 &_Local/Makefile-_&<&'archtype'&>
2002 &_Local/Makefile-_&<&'ostype'&>-<&'archtype'&>
2003 &_OS/Makefile-Base_&
2004 .endd
2005 .cindex "&_Local/Makefile_&"
2006 .cindex "building Exim" "operating system type"
2007 .cindex "building Exim" "architecture type"
2008 where <&'ostype'&> is the operating system type and <&'archtype'&> is the
2009 architecture type. &_Local/Makefile_& is required to exist, and the building
2010 process fails if it is absent. The other three &_Local_& files are optional,
2011 and are often not needed.
2013 The values used for <&'ostype'&> and <&'archtype'&> are obtained from scripts
2014 called &_scripts/os-type_& and &_scripts/arch-type_& respectively. If either of
2015 the environment variables EXIM_OSTYPE or EXIM_ARCHTYPE is set, their
2016 values are used, thereby providing a means of forcing particular settings.
2017 Otherwise, the scripts try to get values from the &%uname%& command. If this
2018 fails, the shell variables OSTYPE and ARCHTYPE are inspected. A number
2019 of &'ad hoc'& transformations are then applied, to produce the standard names
2020 that Exim expects. You can run these scripts directly from the shell in order
2021 to find out what values are being used on your system.
2024 &_OS/Makefile-Default_& contains comments about the variables that are set
2025 therein. Some (but not all) are mentioned below. If there is something that
2026 needs changing, review the contents of this file and the contents of the make
2027 file for your operating system (&_OS/Makefile-<ostype>_&) to see what the
2028 default values are.
2031 .cindex "building Exim" "overriding default settings"
2032 If you need to change any of the values that are set in &_OS/Makefile-Default_&
2033 or in &_OS/Makefile-<ostype>_&, or to add any new definitions, you do not
2034 need to change the original files. Instead, you should make the changes by
2035 putting the new values in an appropriate &_Local_& file. For example,
2036 .cindex "Tru64-Unix build-time settings"
2037 when building Exim in many releases of the Tru64-Unix (formerly Digital UNIX,
2038 formerly DEC-OSF1) operating system, it is necessary to specify that the C
2039 compiler is called &'cc'& rather than &'gcc'&. Also, the compiler must be
2040 called with the option &%-std1%&, to make it recognize some of the features of
2041 Standard C that Exim uses. (Most other compilers recognize Standard C by
2042 default.) To do this, you should create a file called &_Local/Makefile-OSF1_&
2043 containing the lines
2044 .code
2045 CC=cc
2046 CFLAGS=-std1
2047 .endd
2048 If you are compiling for just one operating system, it may be easier to put
2049 these lines directly into &_Local/Makefile_&.
2051 Keeping all your local configuration settings separate from the distributed
2052 files makes it easy to transfer them to new versions of Exim simply by copying
2053 the contents of the &_Local_& directory.
2056 .cindex "NIS lookup type" "including support for"
2057 .cindex "NIS+ lookup type" "including support for"
2058 .cindex "LDAP" "including support for"
2059 .cindex "lookup" "inclusion in binary"
2060 Exim contains support for doing LDAP, NIS, NIS+, and other kinds of file
2061 lookup, but not all systems have these components installed, so the default is
2062 not to include the relevant code in the binary. All the different kinds of file
2063 and database lookup that Exim supports are implemented as separate code modules
2064 which are included only if the relevant compile-time options are set. In the
2065 case of LDAP, NIS, and NIS+, the settings for &_Local/Makefile_& are:
2066 .code
2067 LOOKUP_LDAP=yes
2068 LOOKUP_NIS=yes
2070 .endd
2071 and similar settings apply to the other lookup types. They are all listed in
2072 &_src/EDITME_&. In many cases the relevant include files and interface
2073 libraries need to be installed before compiling Exim.
2074 .cindex "cdb" "including support for"
2075 However, there are some optional lookup types (such as cdb) for which
2076 the code is entirely contained within Exim, and no external include
2077 files or libraries are required. When a lookup type is not included in the
2078 binary, attempts to configure Exim to use it cause run time configuration
2079 errors.
2081 .cindex "Perl" "including support for"
2082 Exim can be linked with an embedded Perl interpreter, allowing Perl
2083 subroutines to be called during string expansion. To enable this facility,
2084 .code
2085 EXIM_PERL=perl.o
2086 .endd
2087 must be defined in &_Local/Makefile_&. Details of this facility are given in
2088 chapter &<<CHAPperl>>&.
2090 .cindex "X11 libraries, location of"
2091 The location of the X11 libraries is something that varies a lot between
2092 operating systems, and there may be different versions of X11 to cope
2093 with. Exim itself makes no use of X11, but if you are compiling the Exim
2094 monitor, the X11 libraries must be available.
2095 The following three variables are set in &_OS/Makefile-Default_&:
2096 .code
2097 X11=/usr/X11R6
2098 XINCLUDE=-I$(X11)/include
2099 XLFLAGS=-L$(X11)/lib
2100 .endd
2101 These are overridden in some of the operating-system configuration files. For
2102 example, in &_OS/Makefile-SunOS5_& there is
2103 .code
2104 X11=/usr/openwin
2105 XINCLUDE=-I$(X11)/include
2106 XLFLAGS=-L$(X11)/lib -R$(X11)/lib
2107 .endd
2108 If you need to override the default setting for your operating system, place a
2109 definition of all three of these variables into your
2110 &_Local/Makefile-<ostype>_& file.
2112 .cindex "EXTRALIBS"
2113 If you need to add any extra libraries to the link steps, these can be put in a
2114 variable called EXTRALIBS, which appears in all the link commands, but by
2115 default is not defined. In contrast, EXTRALIBS_EXIM is used only on the
2116 command for linking the main Exim binary, and not for any associated utilities.
2118 .cindex "DBM libraries" "configuration for building"
2119 There is also DBMLIB, which appears in the link commands for binaries that
2120 use DBM functions (see also section &<<SECTdb>>&). Finally, there is
2121 EXTRALIBS_EXIMON, which appears only in the link step for the Exim monitor
2122 binary, and which can be used, for example, to include additional X11
2123 libraries.
2125 .cindex "configuration file" "editing"
2126 The make file copes with rebuilding Exim correctly if any of the configuration
2127 files are edited. However, if an optional configuration file is deleted, it is
2128 necessary to touch the associated non-optional file (that is,
2129 &_Local/Makefile_& or &_Local/eximon.conf_&) before rebuilding.
2132 .section "OS-specific header files" "SECID30"
2133 .cindex "&_os.h_&"
2134 .cindex "building Exim" "OS-specific C header files"
2135 The &_OS_& directory contains a number of files with names of the form
2136 &_os.h-<ostype>_&. These are system-specific C header files that should not
2137 normally need to be changed. There is a list of macro settings that are
2138 recognized in the file &_OS/os.configuring_&, which should be consulted if you
2139 are porting Exim to a new operating system.
2143 .section "Overriding build-time options for the monitor" "SECID31"
2144 .cindex "building Eximon"
2145 A similar process is used for overriding things when building the Exim monitor,
2146 where the files that are involved are
2147 .display
2148 &_OS/eximon.conf-Default_&
2149 &_OS/eximon.conf-_&<&'ostype'&>
2150 &_Local/eximon.conf_&
2151 &_Local/eximon.conf-_&<&'ostype'&>
2152 &_Local/eximon.conf-_&<&'archtype'&>
2153 &_Local/eximon.conf-_&<&'ostype'&>-<&'archtype'&>
2154 .endd
2155 .cindex "&_Local/eximon.conf_&"
2156 As with Exim itself, the final three files need not exist, and in this case the
2157 &_OS/eximon.conf-<ostype>_& file is also optional. The default values in
2158 &_OS/eximon.conf-Default_& can be overridden dynamically by setting environment
2159 variables of the same name, preceded by EXIMON_. For example, setting
2160 EXIMON_LOG_DEPTH in the environment overrides the value of
2161 LOG_DEPTH at run time.
2162 .ecindex IIDbuex
2165 .section "Installing Exim binaries and scripts" "SECID32"
2166 .cindex "installing Exim"
2167 .cindex "BIN_DIRECTORY"
2168 The command &`make install`& runs the &(exim_install)& script with no
2169 arguments. The script copies binaries and utility scripts into the directory
2170 whose name is specified by the BIN_DIRECTORY setting in &_Local/Makefile_&.
2171 .cindex "setuid" "installing Exim with"
2172 The install script copies files only if they are newer than the files they are
2173 going to replace. The Exim binary is required to be owned by root and have the
2174 &'setuid'& bit set, for normal configurations. Therefore, you must run &`make
2175 install`& as root so that it can set up the Exim binary in this way. However, in
2176 some special situations (for example, if a host is doing no local deliveries)
2177 it may be possible to run Exim without making the binary setuid root (see
2178 chapter &<<CHAPsecurity>>& for details).
2180 .cindex "CONFIGURE_FILE"
2181 Exim's run time configuration file is named by the CONFIGURE_FILE setting
2182 in &_Local/Makefile_&. If this names a single file, and the file does not
2183 exist, the default configuration file &_src/configure.default_& is copied there
2184 by the installation script. If a run time configuration file already exists, it
2185 is left alone. If CONFIGURE_FILE is a colon-separated list, naming several
2186 alternative files, no default is installed.
2188 .cindex "system aliases file"
2189 .cindex "&_/etc/aliases_&"
2190 One change is made to the default configuration file when it is installed: the
2191 default configuration contains a router that references a system aliases file.
2192 The path to this file is set to the value specified by
2193 SYSTEM_ALIASES_FILE in &_Local/Makefile_& (&_/etc/aliases_& by default).
2194 If the system aliases file does not exist, the installation script creates it,
2195 and outputs a comment to the user.
2197 The created file contains no aliases, but it does contain comments about the
2198 aliases a site should normally have. Mail aliases have traditionally been
2199 kept in &_/etc/aliases_&. However, some operating systems are now using
2200 &_/etc/mail/aliases_&. You should check if yours is one of these, and change
2201 Exim's configuration if necessary.
2203 The default configuration uses the local host's name as the only local domain,
2204 and is set up to do local deliveries into the shared directory &_/var/mail_&,
2205 running as the local user. System aliases and &_.forward_& files in users' home
2206 directories are supported, but no NIS or NIS+ support is configured. Domains
2207 other than the name of the local host are routed using the DNS, with delivery
2208 over SMTP.
2210 It is possible to install Exim for special purposes (such as building a binary
2211 distribution) in a private part of the file system. You can do this by a
2212 command such as
2213 .code
2214 make DESTDIR=/some/directory/ install
2215 .endd
2216 This has the effect of pre-pending the specified directory to all the file
2217 paths, except the name of the system aliases file that appears in the default
2218 configuration. (If a default alias file is created, its name &'is'& modified.)
2219 For backwards compatibility, ROOT is used if DESTDIR is not set,
2220 but this usage is deprecated.
2222 .cindex "installing Exim" "what is not installed"
2223 Running &'make install'& does not copy the Exim 4 conversion script
2224 &'convert4r4'&. You will probably run this only once if you are
2225 upgrading from Exim 3. None of the documentation files in the &_doc_&
2226 directory are copied, except for the info files when you have set
2227 INFO_DIRECTORY, as described in section &<<SECTinsinfdoc>>& below.
2229 For the utility programs, old versions are renamed by adding the suffix &_.O_&
2230 to their names. The Exim binary itself, however, is handled differently. It is
2231 installed under a name that includes the version number and the compile number,
2232 for example &_exim-&version;-1_&. The script then arranges for a symbolic link
2233 called &_exim_& to point to the binary. If you are updating a previous version
2234 of Exim, the script takes care to ensure that the name &_exim_& is never absent
2235 from the directory (as seen by other processes).
2237 .cindex "installing Exim" "testing the script"
2238 If you want to see what the &'make install'& will do before running it for
2239 real, you can pass the &%-n%& option to the installation script by this
2240 command:
2241 .code
2242 make INSTALL_ARG=-n install
2243 .endd
2244 The contents of the variable INSTALL_ARG are passed to the installation
2245 script. You do not need to be root to run this test. Alternatively, you can run
2246 the installation script directly, but this must be from within the build
2247 directory. For example, from the top-level Exim directory you could use this
2248 command:
2249 .code
2250 (cd build-SunOS5-5.5.1-sparc; ../scripts/exim_install -n)
2251 .endd
2252 .cindex "installing Exim" "install script options"
2253 There are two other options that can be supplied to the installation script.
2255 .ilist
2256 &%-no_chown%& bypasses the call to change the owner of the installed binary
2257 to root, and the call to make it a setuid binary.
2258 .next
2259 &%-no_symlink%& bypasses the setting up of the symbolic link &_exim_& to the
2260 installed binary.
2261 .endlist
2263 INSTALL_ARG can be used to pass these options to the script. For example:
2264 .code
2265 make INSTALL_ARG=-no_symlink install
2266 .endd
2267 The installation script can also be given arguments specifying which files are
2268 to be copied. For example, to install just the Exim binary, and nothing else,
2269 without creating the symbolic link, you could use:
2270 .code
2271 make INSTALL_ARG='-no_symlink exim' install
2272 .endd
2276 .section "Installing info documentation" "SECTinsinfdoc"
2277 .cindex "installing Exim" "&'info'& documentation"
2278 Not all systems use the GNU &'info'& system for documentation, and for this
2279 reason, the Texinfo source of Exim's documentation is not included in the main
2280 distribution. Instead it is available separately from the ftp site (see section
2281 &<<SECTavail>>&).
2283 If you have defined INFO_DIRECTORY in &_Local/Makefile_& and the Texinfo
2284 source of the documentation is found in the source tree, running &`make
2285 install`& automatically builds the info files and installs them.
2289 .section "Setting up the spool directory" "SECID33"
2290 .cindex "spool directory" "creating"
2291 When it starts up, Exim tries to create its spool directory if it does not
2292 exist. The Exim uid and gid are used for the owner and group of the spool
2293 directory. Sub-directories are automatically created in the spool directory as
2294 necessary.
2299 .section "Testing" "SECID34"
2300 .cindex "testing" "installation"
2301 Having installed Exim, you can check that the run time configuration file is
2302 syntactically valid by running the following command, which assumes that the
2303 Exim binary directory is within your PATH environment variable:
2304 .code
2305 exim -bV
2306 .endd
2307 If there are any errors in the configuration file, Exim outputs error messages.
2308 Otherwise it outputs the version number and build date,
2309 the DBM library that is being used, and information about which drivers and
2310 other optional code modules are included in the binary.
2311 Some simple routing tests can be done by using the address testing option. For
2312 example,
2313 .display
2314 &`exim -bt`& <&'local username'&>
2315 .endd
2316 should verify that it recognizes a local mailbox, and
2317 .display
2318 &`exim -bt`& <&'remote address'&>
2319 .endd
2320 a remote one. Then try getting it to deliver mail, both locally and remotely.
2321 This can be done by passing messages directly to Exim, without going through a
2322 user agent. For example:
2323 .code
2324 exim -v postmaster@your.domain.example
2325 From: user@your.domain.example
2326 To: postmaster@your.domain.example
2327 Subject: Testing Exim
2329 This is a test message.
2330 ^D
2331 .endd
2332 The &%-v%& option causes Exim to output some verification of what it is doing.
2333 In this case you should see copies of three log lines, one for the message's
2334 arrival, one for its delivery, and one containing &"Completed"&.
2336 .cindex "delivery" "problems with"
2337 If you encounter problems, look at Exim's log files (&'mainlog'& and
2338 &'paniclog'&) to see if there is any relevant information there. Another source
2339 of information is running Exim with debugging turned on, by specifying the
2340 &%-d%& option. If a message is stuck on Exim's spool, you can force a delivery
2341 with debugging turned on by a command of the form
2342 .display
2343 &`exim -d -M`& <&'exim-message-id'&>
2344 .endd
2345 You must be root or an &"admin user"& in order to do this. The &%-d%& option
2346 produces rather a lot of output, but you can cut this down to specific areas.
2347 For example, if you use &%-d-all+route%& only the debugging information
2348 relevant to routing is included. (See the &%-d%& option in chapter
2349 &<<CHAPcommandline>>& for more details.)
2351 .cindex '&"sticky"& bit'
2352 .cindex "lock files"
2353 One specific problem that has shown up on some sites is the inability to do
2354 local deliveries into a shared mailbox directory, because it does not have the
2355 &"sticky bit"& set on it. By default, Exim tries to create a lock file before
2356 writing to a mailbox file, and if it cannot create the lock file, the delivery
2357 is deferred. You can get round this either by setting the &"sticky bit"& on the
2358 directory, or by setting a specific group for local deliveries and allowing
2359 that group to create files in the directory (see the comments above the
2360 &(local_delivery)& transport in the default configuration file). Another
2361 approach is to configure Exim not to use lock files, but just to rely on
2362 &[fcntl()]& locking instead. However, you should do this only if all user
2363 agents also use &[fcntl()]& locking. For further discussion of locking issues,
2364 see chapter &<<CHAPappendfile>>&.
2366 One thing that cannot be tested on a system that is already running an MTA is
2367 the receipt of incoming SMTP mail on the standard SMTP port. However, the
2368 &%-oX%& option can be used to run an Exim daemon that listens on some other
2369 port, or &'inetd'& can be used to do this. The &%-bh%& option and the
2370 &'exim_checkaccess'& utility can be used to check out policy controls on
2371 incoming SMTP mail.
2373 Testing a new version on a system that is already running Exim can most easily
2374 be done by building a binary with a different CONFIGURE_FILE setting. From
2375 within the run time configuration, all other file and directory names
2376 that Exim uses can be altered, in order to keep it entirely clear of the
2377 production version.
2380 .section "Replacing another MTA with Exim" "SECID35"
2381 .cindex "replacing another MTA"
2382 Building and installing Exim for the first time does not of itself put it in
2383 general use. The name by which the system's MTA is called by mail user agents
2384 is either &_/usr/sbin/sendmail_&, or &_/usr/lib/sendmail_& (depending on the
2385 operating system), and it is necessary to make this name point to the &'exim'&
2386 binary in order to get the user agents to pass messages to Exim. This is
2387 normally done by renaming any existing file and making &_/usr/sbin/sendmail_&
2388 or &_/usr/lib/sendmail_&
2389 .cindex "symbolic link" "to &'exim'& binary"
2390 a symbolic link to the &'exim'& binary. It is a good idea to remove any setuid
2391 privilege and executable status from the old MTA. It is then necessary to stop
2392 and restart the mailer daemon, if one is running.
2394 .cindex "FreeBSD, MTA indirection"
2395 .cindex "&_/etc/mail/mailer.conf_&"
2396 Some operating systems have introduced alternative ways of switching MTAs. For
2397 example, if you are running FreeBSD, you need to edit the file
2398 &_/etc/mail/mailer.conf_& instead of setting up a symbolic link as just
2399 described. A typical example of the contents of this file for running Exim is
2400 as follows:
2401 .code
2402 sendmail /usr/exim/bin/exim
2403 send-mail /usr/exim/bin/exim
2404 mailq /usr/exim/bin/exim -bp
2405 newaliases /usr/bin/true
2406 .endd
2407 Once you have set up the symbolic link, or edited &_/etc/mail/mailer.conf_&,
2408 your Exim installation is &"live"&. Check it by sending a message from your
2409 favourite user agent.
2411 You should consider what to tell your users about the change of MTA. Exim may
2412 have different capabilities to what was previously running, and there are
2413 various operational differences such as the text of messages produced by
2414 command line options and in bounce messages. If you allow your users to make
2415 use of Exim's filtering capabilities, you should make the document entitled
2416 &'Exim's interface to mail filtering'& available to them.
2420 .section "Upgrading Exim" "SECID36"
2421 .cindex "upgrading Exim"
2422 If you are already running Exim on your host, building and installing a new
2423 version automatically makes it available to MUAs, or any other programs that
2424 call the MTA directly. However, if you are running an Exim daemon, you do need
2425 to send it a HUP signal, to make it re-execute itself, and thereby pick up the
2426 new binary. You do not need to stop processing mail in order to install a new
2427 version of Exim. The install script does not modify an existing runtime
2428 configuration file.
2433 .section "Stopping the Exim daemon on Solaris" "SECID37"
2434 .cindex "Solaris" "stopping Exim on"
2435 The standard command for stopping the mailer daemon on Solaris is
2436 .code
2437 /etc/init.d/sendmail stop
2438 .endd
2439 If &_/usr/lib/sendmail_& has been turned into a symbolic link, this script
2440 fails to stop Exim because it uses the command &'ps -e'& and greps the output
2441 for the text &"sendmail"&; this is not present because the actual program name
2442 (that is, &"exim"&) is given by the &'ps'& command with these options. A
2443 solution is to replace the line that finds the process id with something like
2444 .code
2445 pid=`cat /var/spool/exim/exim-daemon.pid`
2446 .endd
2447 to obtain the daemon's pid directly from the file that Exim saves it in.
2449 Note, however, that stopping the daemon does not &"stop Exim"&. Messages can
2450 still be received from local processes, and if automatic delivery is configured
2451 (the normal case), deliveries will still occur.
2456 . ////////////////////////////////////////////////////////////////////////////
2457 . ////////////////////////////////////////////////////////////////////////////
2459 .chapter "The Exim command line" "CHAPcommandline"
2460 .scindex IIDclo1 "command line" "options"
2461 .scindex IIDclo2 "options" "command line"
2462 Exim's command line takes the standard Unix form of a sequence of options,
2463 each starting with a hyphen character, followed by a number of arguments. The
2464 options are compatible with the main options of Sendmail, and there are also
2465 some additional options, some of which are compatible with Smail 3. Certain
2466 combinations of options do not make sense, and provoke an error if used.
2467 The form of the arguments depends on which options are set.
2470 .section "Setting options by program name" "SECID38"
2471 .cindex "&'mailq'&"
2472 If Exim is called under the name &'mailq'&, it behaves as if the option &%-bp%&
2473 were present before any other options.
2474 The &%-bp%& option requests a listing of the contents of the mail queue on the
2475 standard output.
2476 This feature is for compatibility with some systems that contain a command of
2477 that name in one of the standard libraries, symbolically linked to
2478 &_/usr/sbin/sendmail_& or &_/usr/lib/sendmail_&.
2480 .cindex "&'rsmtp'&"
2481 If Exim is called under the name &'rsmtp'& it behaves as if the option &%-bS%&
2482 were present before any other options, for compatibility with Smail. The
2483 &%-bS%& option is used for reading in a number of messages in batched SMTP
2484 format.
2486 .cindex "&'rmail'&"
2487 If Exim is called under the name &'rmail'& it behaves as if the &%-i%& and
2488 &%-oee%& options were present before any other options, for compatibility with
2489 Smail. The name &'rmail'& is used as an interface by some UUCP systems.
2491 .cindex "&'runq'&"
2492 .cindex "queue runner"
2493 If Exim is called under the name &'runq'& it behaves as if the option &%-q%&
2494 were present before any other options, for compatibility with Smail. The &%-q%&
2495 option causes a single queue runner process to be started.
2497 .cindex "&'newaliases'&"
2498 .cindex "alias file" "building"
2499 .cindex "Sendmail compatibility" "calling Exim as &'newaliases'&"
2500 If Exim is called under the name &'newaliases'& it behaves as if the option
2501 &%-bi%& were present before any other options, for compatibility with Sendmail.
2502 This option is used for rebuilding Sendmail's alias file. Exim does not have
2503 the concept of a single alias file, but can be configured to run a given
2504 command if called with the &%-bi%& option.
2507 .section "Trusted and admin users" "SECTtrustedadmin"
2508 Some Exim options are available only to &'trusted users'& and others are
2509 available only to &'admin users'&. In the description below, the phrases &"Exim
2510 user"& and &"Exim group"& mean the user and group defined by EXIM_USER and
2511 EXIM_GROUP in &_Local/Makefile_& or set by the &%exim_user%& and
2512 &%exim_group%& options. These do not necessarily have to use the name &"exim"&.
2514 .ilist
2515 .cindex "trusted users" "definition of"
2516 .cindex "user" "trusted definition of"
2517 The trusted users are root, the Exim user, any user listed in the
2518 &%trusted_users%& configuration option, and any user whose current group or any
2519 supplementary group is one of those listed in the &%trusted_groups%&
2520 configuration option. Note that the Exim group is not automatically trusted.
2522 .cindex '&"From"& line'
2523 .cindex "envelope sender"
2524 Trusted users are always permitted to use the &%-f%& option or a leading
2525 &"From&~"& line to specify the envelope sender of a message that is passed to
2526 Exim through the local interface (see the &%-bm%& and &%-f%& options below).
2527 See the &%untrusted_set_sender%& option for a way of permitting non-trusted
2528 users to set envelope senders.
2530 .cindex "&'From:'& header line"
2531 .cindex "&'Sender:'& header line"
2532 For a trusted user, there is never any check on the contents of the &'From:'&
2533 header line, and a &'Sender:'& line is never added. Furthermore, any existing
2534 &'Sender:'& line in incoming local (non-TCP/IP) messages is not removed.
2536 Trusted users may also specify a host name, host address, interface address,
2537 protocol name, ident value, and authentication data when submitting a message
2538 locally. Thus, they are able to insert messages into Exim's queue locally that
2539 have the characteristics of messages received from a remote host. Untrusted
2540 users may in some circumstances use &%-f%&, but can never set the other values
2541 that are available to trusted users.
2542 .next
2543 .cindex "user" "admin definition of"
2544 .cindex "admin user" "definition of"
2545 The admin users are root, the Exim user, and any user that is a member of the
2546 Exim group or of any group listed in the &%admin_groups%& configuration option.
2547 The current group does not have to be one of these groups.
2549 Admin users are permitted to list the queue, and to carry out certain
2550 operations on messages, for example, to force delivery failures. It is also
2551 necessary to be an admin user in order to see the full information provided by
2552 the Exim monitor, and full debugging output.
2554 By default, the use of the &%-M%&, &%-q%&, &%-R%&, and &%-S%& options to cause
2555 Exim to attempt delivery of messages on its queue is restricted to admin users.
2556 However, this restriction can be relaxed by setting the &%prod_requires_admin%&
2557 option false (that is, specifying &%no_prod_requires_admin%&).
2559 Similarly, the use of the &%-bp%& option to list all the messages in the queue
2560 is restricted to admin users unless &%queue_list_requires_admin%& is set
2561 false.
2562 .endlist
2565 &*Warning*&: If you configure your system so that admin users are able to
2566 edit Exim's configuration file, you are giving those users an easy way of
2567 getting root. There is further discussion of this issue at the start of chapter
2568 &<<CHAPconf>>&.
2573 .section "Command line options" "SECID39"
2574 Exim's command line options are described in alphabetical order below. If none
2575 of the options that specifies a specific action (such as starting the daemon or
2576 a queue runner, or testing an address, or receiving a message in a specific
2577 format, or listing the queue) are present, and there is at least one argument
2578 on the command line, &%-bm%& (accept a local message on the standard input,
2579 with the arguments specifying the recipients) is assumed. Otherwise, Exim
2580 outputs a brief message about itself and exits.
2582 . ////////////////////////////////////////////////////////////////////////////
2583 . Insert a stylized XML comment here, to identify the start of the command line
2584 . options. This is for the benefit of the Perl script that automatically
2585 . creates a man page for the options.
2586 . ////////////////////////////////////////////////////////////////////////////
2588 .literal xml
2589 <!-- === Start of command line options === -->
2590 .literal off
2593 .vlist
2594 .vitem &%--%&
2595 .oindex "--"
2596 .cindex "options" "command line; terminating"
2597 This is a pseudo-option whose only purpose is to terminate the options and
2598 therefore to cause subsequent command line items to be treated as arguments
2599 rather than options, even if they begin with hyphens.
2601 .vitem &%--help%&
2602 .oindex "&%--help%&"
2603 This option causes Exim to output a few sentences stating what it is.
2604 The same output is generated if the Exim binary is called with no options and
2605 no arguments.
2607 .vitem &%--version%&
2608 .oindex "&%--version%&"
2609 This option is an alias for &%-bV%& and causes version information to be
2610 displayed.
2612 .vitem &%-B%&<&'type'&>
2613 .oindex "&%-B%&"
2614 .cindex "8-bit characters"
2615 .cindex "Sendmail compatibility" "8-bit characters"
2616 This is a Sendmail option for selecting 7 or 8 bit processing. Exim is 8-bit
2617 clean; it ignores this option.
2619 .vitem &%-bd%&
2620 .oindex "&%-bd%&"
2621 .cindex "daemon"
2622 .cindex "SMTP" "listener"
2623 .cindex "queue runner"
2624 This option runs Exim as a daemon, awaiting incoming SMTP connections. Usually
2625 the &%-bd%& option is combined with the &%-q%&<&'time'&> option, to specify
2626 that the daemon should also initiate periodic queue runs.
2628 The &%-bd%& option can be used only by an admin user. If either of the &%-d%&
2629 (debugging) or &%-v%& (verifying) options are set, the daemon does not
2630 disconnect from the controlling terminal. When running this way, it can be
2631 stopped by pressing ctrl-C.
2633 By default, Exim listens for incoming connections to the standard SMTP port on
2634 all the host's running interfaces. However, it is possible to listen on other
2635 ports, on multiple ports, and only on specific interfaces. Chapter
2636 &<<CHAPinterfaces>>& contains a description of the options that control this.
2638 When a listening daemon
2639 .cindex "daemon" "process id (pid)"
2640 .cindex "pid (process id)" "of daemon"
2641 is started without the use of &%-oX%& (that is, without overriding the normal
2642 configuration), it writes its process id to a file called &_exim-daemon.pid_&
2643 in Exim's spool directory. This location can be overridden by setting
2644 PID_FILE_PATH in &_Local/Makefile_&. The file is written while Exim is still
2645 running as root.
2647 When &%-oX%& is used on the command line to start a listening daemon, the
2648 process id is not written to the normal pid file path. However, &%-oP%& can be
2649 used to specify a path on the command line if a pid file is required.
2651 The SIGHUP signal
2652 .cindex "SIGHUP"
2653 .cindex "daemon" "restarting"
2654 can be used to cause the daemon to re-execute itself. This should be done
2655 whenever Exim's configuration file, or any file that is incorporated into it by
2656 means of the &%.include%& facility, is changed, and also whenever a new version
2657 of Exim is installed. It is not necessary to do this when other files that are
2658 referenced from the configuration (for example, alias files) are changed,
2659 because these are reread each time they are used.
2661 .vitem &%-bdf%&
2662 .oindex "&%-bdf%&"
2663 This option has the same effect as &%-bd%& except that it never disconnects
2664 from the controlling terminal, even when no debugging is specified.
2666 .vitem &%-be%&
2667 .oindex "&%-be%&"
2668 .cindex "testing" "string expansion"
2669 .cindex "expansion" "testing"
2670 Run Exim in expansion testing mode. Exim discards its root privilege, to
2671 prevent ordinary users from using this mode to read otherwise inaccessible
2672 files. If no arguments are given, Exim runs interactively, prompting for lines
2673 of data. Otherwise, it processes each argument in turn.
2675 If Exim was built with USE_READLINE=yes in &_Local/Makefile_&, it tries
2676 to load the &%libreadline%& library dynamically whenever the &%-be%& option is
2677 used without command line arguments. If successful, it uses the &[readline()]&
2678 function, which provides extensive line-editing facilities, for reading the
2679 test data. A line history is supported.
2681 Long expansion expressions can be split over several lines by using backslash
2682 continuations. As in Exim's run time configuration, white space at the start of
2683 continuation lines is ignored. Each argument or data line is passed through the
2684 string expansion mechanism, and the result is output. Variable values from the
2685 configuration file (for example, &$qualify_domain$&) are available, but no
2686 message-specific values (such as &$sender_domain$&) are set, because no message
2687 is being processed (but see &%-bem%& and &%-Mset%&).
2689 &*Note*&: If you use this mechanism to test lookups, and you change the data
2690 files or databases you are using, you must exit and restart Exim before trying
2691 the same lookup again. Otherwise, because each Exim process caches the results
2692 of lookups, you will just get the same result as before.
2694 .vitem &%-bem%&&~<&'filename'&>
2695 .oindex "&%-bem%&"
2696 .cindex "testing" "string expansion"
2697 .cindex "expansion" "testing"
2698 This option operates like &%-be%& except that it must be followed by the name
2699 of a file. For example:
2700 .code
2701 exim -bem /tmp/testmessage
2702 .endd
2703 The file is read as a message (as if receiving a locally-submitted non-SMTP
2704 message) before any of the test expansions are done. Thus, message-specific
2705 variables such as &$message_size$& and &$header_from:$& are available. However,
2706 no &'Received:'& header is added to the message. If the &%-t%& option is set,
2707 recipients are read from the headers in the normal way, and are shown in the
2708 &$recipients$& variable. Note that recipients cannot be given on the command
2709 line, because further arguments are taken as strings to expand (just like
2710 &%-be%&).
2712 .vitem &%-bF%&&~<&'filename'&>
2713 .oindex "&%-bF%&"
2714 .cindex "system filter" "testing"
2715 .cindex "testing" "system filter"
2716 This option is the same as &%-bf%& except that it assumes that the filter being
2717 tested is a system filter. The additional commands that are available only in
2718 system filters are recognized.
2720 .vitem &%-bf%&&~<&'filename'&>
2721 .oindex "&%-bf%&"
2722 .cindex "filter" "testing"
2723 .cindex "testing" "filter file"
2724 .cindex "forward file" "testing"
2725 .cindex "testing" "forward file"
2726 .cindex "Sieve filter" "testing"
2727 This option runs Exim in user filter testing mode; the file is the filter file
2728 to be tested, and a test message must be supplied on the standard input. If
2729 there are no message-dependent tests in the filter, an empty file can be
2730 supplied.
2732 If you want to test a system filter file, use &%-bF%& instead of &%-bf%&. You
2733 can use both &%-bF%& and &%-bf%& on the same command, in order to test a system
2734 filter and a user filter in the same run. For example:
2735 .code
2736 exim -bF /system/filter -bf /user/filter </test/message
2737 .endd
2738 This is helpful when the system filter adds header lines or sets filter
2739 variables that are used by the user filter.
2741 If the test filter file does not begin with one of the special lines
2742 .code
2743 # Exim filter
2744 # Sieve filter
2745 .endd
2746 it is taken to be a normal &_.forward_& file, and is tested for validity under
2747 that interpretation. See sections &<<SECTitenonfilred>>& to
2748 &<<SECTspecitredli>>& for a description of the possible contents of non-filter
2749 redirection lists.
2751 The result of an Exim command that uses &%-bf%&, provided no errors are
2752 detected, is a list of the actions that Exim would try to take if presented
2753 with the message for real. More details of filter testing are given in the
2754 separate document entitled &'Exim's interfaces to mail filtering'&.
2756 When testing a filter file,
2757 .cindex "&""From""& line"
2758 .cindex "envelope sender"
2759 .oindex "&%-f%&" "for filter testing"
2760 the envelope sender can be set by the &%-f%& option,
2761 or by a &"From&~"& line at the start of the test message. Various parameters
2762 that would normally be taken from the envelope recipient address of the message
2763 can be set by means of additional command line options (see the next four
2764 options).
2766 .vitem &%-bfd%&&~<&'domain'&>
2767 .oindex "&%-bfd%&"
2768 .vindex "&$qualify_domain$&"
2769 This sets the domain of the recipient address when a filter file is being
2770 tested by means of the &%-bf%& option. The default is the value of
2771 &$qualify_domain$&.
2773 .vitem &%-bfl%&&~<&'local&~part'&>
2774 .oindex "&%-bfl%&"
2775 This sets the local part of the recipient address when a filter file is being
2776 tested by means of the &%-bf%& option. The default is the username of the
2777 process that calls Exim. A local part should be specified with any prefix or
2778 suffix stripped, because that is how it appears to the filter when a message is
2779 actually being delivered.
2781 .vitem &%-bfp%&&~<&'prefix'&>
2782 .oindex "&%-bfp%&"
2783 This sets the prefix of the local part of the recipient address when a filter
2784 file is being tested by means of the &%-bf%& option. The default is an empty
2785 prefix.
2787 .vitem &%-bfs%&&~<&'suffix'&>
2788 .oindex "&%-bfs%&"
2789 This sets the suffix of the local part of the recipient address when a filter
2790 file is being tested by means of the &%-bf%& option. The default is an empty
2791 suffix.
2793 .vitem &%-bh%&&~<&'IP&~address'&>
2794 .oindex "&%-bh%&"
2795 .cindex "testing" "incoming SMTP"
2796 .cindex "SMTP" "testing incoming"
2797 .cindex "testing" "relay control"
2798 .cindex "relaying" "testing configuration"
2799 .cindex "policy control" "testing"
2800 .cindex "debugging" "&%-bh%& option"
2801 This option runs a fake SMTP session as if from the given IP address, using the
2802 standard input and output. The IP address may include a port number at the end,
2803 after a full stop. For example:
2804 .code
2805 exim -bh
2806 exim -bh fe80::a00:20ff:fe86:a061.5678
2807 .endd
2808 When an IPv6 address is given, it is converted into canonical form. In the case
2809 of the second example above, the value of &$sender_host_address$& after
2810 conversion to the canonical form is
2811 &`fe80:0000:0000:0a00:20ff:fe86:a061.5678`&.
2813 Comments as to what is going on are written to the standard error file. These
2814 include lines beginning with &"LOG"& for anything that would have been logged.
2815 This facility is provided for testing configuration options for incoming
2816 messages, to make sure they implement the required policy. For example, you can
2817 test your relay controls using &%-bh%&.
2819 &*Warning 1*&:
2820 .cindex "RFC 1413"
2821 You can test features of the configuration that rely on ident (RFC 1413)
2822 information by using the &%-oMt%& option. However, Exim cannot actually perform
2823 an ident callout when testing using &%-bh%& because there is no incoming SMTP
2824 connection.
2826 &*Warning 2*&: Address verification callouts (see section &<<SECTcallver>>&)
2827 are also skipped when testing using &%-bh%&. If you want these callouts to
2828 occur, use &%-bhc%& instead.
2830 Messages supplied during the testing session are discarded, and nothing is
2831 written to any of the real log files. There may be pauses when DNS (and other)
2832 lookups are taking place, and of course these may time out. The &%-oMi%& option
2833 can be used to specify a specific IP interface and port if this is important,
2834 and &%-oMaa%& and &%-oMai%& can be used to set parameters as if the SMTP
2835 session were authenticated.
2837 The &'exim_checkaccess'& utility is a &"packaged"& version of &%-bh%& whose
2838 output just states whether a given recipient address from a given host is
2839 acceptable or not. See section &<<SECTcheckaccess>>&.
2841 Features such as authentication and encryption, where the client input is not
2842 plain text, cannot easily be tested with &%-bh%&. Instead, you should use a
2843 specialized SMTP test program such as
2844 &url(http://jetmore.org/john/code/#swaks,swaks).
2846 .vitem &%-bhc%&&~<&'IP&~address'&>
2847 .oindex "&%-bhc%&"
2848 This option operates in the same way as &%-bh%&, except that address
2849 verification callouts are performed if required. This includes consulting and
2850 updating the callout cache database.
2852 .vitem &%-bi%&
2853 .oindex "&%-bi%&"
2854 .cindex "alias file" "building"
2855 .cindex "building alias file"
2856 .cindex "Sendmail compatibility" "&%-bi%& option"
2857 Sendmail interprets the &%-bi%& option as a request to rebuild its alias file.
2858 Exim does not have the concept of a single alias file, and so it cannot mimic
2859 this behaviour. However, calls to &_/usr/lib/sendmail_& with the &%-bi%& option
2860 tend to appear in various scripts such as NIS make files, so the option must be
2861 recognized.
2863 If &%-bi%& is encountered, the command specified by the &%bi_command%&
2864 configuration option is run, under the uid and gid of the caller of Exim. If
2865 the &%-oA%& option is used, its value is passed to the command as an argument.
2866 The command set by &%bi_command%& may not contain arguments. The command can
2867 use the &'exim_dbmbuild'& utility, or some other means, to rebuild alias files
2868 if this is required. If the &%bi_command%& option is not set, calling Exim with
2869 &%-bi%& is a no-op.
2871 .vitem &%-bm%&
2872 .oindex "&%-bm%&"
2873 .cindex "local message reception"
2874 This option runs an Exim receiving process that accepts an incoming,
2875 locally-generated message on the current input. The recipients are given as the
2876 command arguments (except when &%-t%& is also present &-- see below). Each
2877 argument can be a comma-separated list of RFC 2822 addresses. This is the
2878 default option for selecting the overall action of an Exim call; it is assumed
2879 if no other conflicting option is present.
2881 If any addresses in the message are unqualified (have no domain), they are
2882 qualified by the values of the &%qualify_domain%& or &%qualify_recipient%&
2883 options, as appropriate. The &%-bnq%& option (see below) provides a way of
2884 suppressing this for special cases.
2886 Policy checks on the contents of local messages can be enforced by means of
2887 the non-SMTP ACL. See chapter &<<CHAPACL>>& for details.
2889 .cindex "return code" "for &%-bm%&"
2890 The return code is zero if the message is successfully accepted. Otherwise, the
2891 action is controlled by the &%-oe%&&'x'& option setting &-- see below.
2893 The format
2894 .cindex "message" "format"
2895 .cindex "format" "message"
2896 .cindex "&""From""& line"
2897 .cindex "UUCP" "&""From""& line"
2898 .cindex "Sendmail compatibility" "&""From""& line"
2899 of the message must be as defined in RFC 2822, except that, for
2900 compatibility with Sendmail and Smail, a line in one of the forms
2901 .code
2902 From sender Fri Jan 5 12:55 GMT 1997
2903 From sender Fri, 5 Jan 97 12:55:01
2904 .endd
2905 (with the weekday optional, and possibly with additional text after the date)
2906 is permitted to appear at the start of the message. There appears to be no
2907 authoritative specification of the format of this line. Exim recognizes it by
2908 matching against the regular expression defined by the &%uucp_from_pattern%&
2909 option, which can be changed if necessary.
2911 .oindex "&%-f%&" "overriding &""From""& line"
2912 The specified sender is treated as if it were given as the argument to the
2913 &%-f%& option, but if a &%-f%& option is also present, its argument is used in
2914 preference to the address taken from the message. The caller of Exim must be a
2915 trusted user for the sender of a message to be set in this way.
2917 .vitem &%-bnq%&
2918 .oindex "&%-bnq%&"
2919 .cindex "address qualification, suppressing"
2920 By default, Exim automatically qualifies unqualified addresses (those
2921 without domains) that appear in messages that are submitted locally (that
2922 is, not over TCP/IP). This qualification applies both to addresses in
2923 envelopes, and addresses in header lines. Sender addresses are qualified using
2924 &%qualify_domain%&, and recipient addresses using &%qualify_recipient%& (which
2925 defaults to the value of &%qualify_domain%&).
2927 Sometimes, qualification is not wanted. For example, if &%-bS%& (batch SMTP) is
2928 being used to re-submit messages that originally came from remote hosts after
2929 content scanning, you probably do not want to qualify unqualified addresses in
2930 header lines. (Such lines will be present only if you have not enabled a header
2931 syntax check in the appropriate ACL.)
2933 The &%-bnq%& option suppresses all qualification of unqualified addresses in
2934 messages that originate on the local host. When this is used, unqualified
2935 addresses in the envelope provoke errors (causing message rejection) and
2936 unqualified addresses in header lines are left alone.
2939 .vitem &%-bP%&
2940 .oindex "&%-bP%&"
2941 .cindex "configuration options" "extracting"
2942 .cindex "options" "configuration &-- extracting"
2943 If this option is given with no arguments, it causes the values of all Exim's
2944 main configuration options to be written to the standard output. The values
2945 of one or more specific options can be requested by giving their names as
2946 arguments, for example:
2947 .code
2948 exim -bP qualify_domain hold_domains
2949 .endd
2950 .cindex "hiding configuration option values"
2951 .cindex "configuration options" "hiding value of"
2952 .cindex "options" "hiding value of"
2953 However, any option setting that is preceded by the word &"hide"& in the
2954 configuration file is not shown in full, except to an admin user. For other
2955 users, the output is as in this example:
2956 .code
2957 mysql_servers = <value not displayable>
2958 .endd
2959 If &%configure_file%& is given as an argument, the name of the run time
2960 configuration file is output.
2961 If a list of configuration files was supplied, the value that is output here
2962 is the name of the file that was actually used.
2964 .cindex "daemon" "process id (pid)"
2965 .cindex "pid (process id)" "of daemon"
2966 If &%log_file_path%& or &%pid_file_path%& are given, the names of the
2967 directories where log files and daemon pid files are written are output,
2968 respectively. If these values are unset, log files are written in a
2969 sub-directory of the spool directory called &%log%&, and the pid file is
2970 written directly into the spool directory.
2972 If &%-bP%& is followed by a name preceded by &`+`&, for example,
2973 .code
2974 exim -bP +local_domains
2975 .endd
2976 it searches for a matching named list of any type (domain, host, address, or
2977 local part) and outputs what it finds.
2979 .cindex "options" "router &-- extracting"
2980 .cindex "options" "transport &-- extracting"
2981 .cindex "options" "authenticator &-- extracting"
2982 If one of the words &%router%&, &%transport%&, or &%authenticator%& is given,
2983 followed by the name of an appropriate driver instance, the option settings for
2984 that driver are output. For example:
2985 .code
2986 exim -bP transport local_delivery
2987 .endd
2988 The generic driver options are output first, followed by the driver's private
2989 options. A list of the names of drivers of a particular type can be obtained by
2990 using one of the words &%router_list%&, &%transport_list%&, or
2991 &%authenticator_list%&, and a complete list of all drivers with their option
2992 settings can be obtained by using &%routers%&, &%transports%&, or
2993 &%authenticators%&.
2995 .cindex "options" "macro &-- extracting"
2996 If invoked by an admin user, then &%macro%&, &%macro_list%& and &%macros%&
2997 are available, similarly to the drivers. Because macros are sometimes used
2998 for storing passwords, this option is restricted.
2999 The output format is one item per line.
3001 .vitem &%-bp%&
3002 .oindex "&%-bp%&"
3003 .cindex "queue" "listing messages on"
3004 .cindex "listing" "messages on the queue"
3005 This option requests a listing of the contents of the mail queue on the
3006 standard output. If the &%-bp%& option is followed by a list of message ids,
3007 just those messages are listed. By default, this option can be used only by an
3008 admin user. However, the &%queue_list_requires_admin%& option can be set false
3009 to allow any user to see the queue.
3011 Each message on the queue is displayed as in the following example:
3012 .code
3013 25m 2.9K 0t5C6f-0000c8-00 <alice@wonderland.fict.example>
3014 red.king@looking-glass.fict.example
3015 <other addresses>
3016 .endd
3017 .cindex "message" "size in queue listing"
3018 .cindex "size" "of message"
3019 The first line contains the length of time the message has been on the queue
3020 (in this case 25 minutes), the size of the message (2.9K), the unique local
3021 identifier for the message, and the message sender, as contained in the
3022 envelope. For bounce messages, the sender address is empty, and appears as
3023 &"<>"&. If the message was submitted locally by an untrusted user who overrode
3024 the default sender address, the user's login name is shown in parentheses
3025 before the sender address.
3027 .cindex "frozen messages" "in queue listing"
3028 If the message is frozen (attempts to deliver it are suspended) then the text
3029 &"*** frozen ***"& is displayed at the end of this line.
3031 The recipients of the message (taken from the envelope, not the headers) are
3032 displayed on subsequent lines. Those addresses to which the message has already
3033 been delivered are marked with the letter D. If an original address gets
3034 expanded into several addresses via an alias or forward file, the original is
3035 displayed with a D only when deliveries for all of its child addresses are
3036 complete.
3039 .vitem &%-bpa%&
3040 .oindex "&%-bpa%&"
3041 This option operates like &%-bp%&, but in addition it shows delivered addresses
3042 that were generated from the original top level address(es) in each message by
3043 alias or forwarding operations. These addresses are flagged with &"+D"& instead
3044 of just &"D"&.
3047 .vitem &%-bpc%&
3048 .oindex "&%-bpc%&"
3049 .cindex "queue" "count of messages on"
3050 This option counts the number of messages on the queue, and writes the total
3051 to the standard output. It is restricted to admin users, unless
3052 &%queue_list_requires_admin%& is set false.
3055 .vitem &%-bpr%&
3056 .oindex "&%-bpr%&"
3057 This option operates like &%-bp%&, but the output is not sorted into
3058 chronological order of message arrival. This can speed it up when there are
3059 lots of messages on the queue, and is particularly useful if the output is
3060 going to be post-processed in a way that doesn't need the sorting.
3062 .vitem &%-bpra%&
3063 .oindex "&%-bpra%&"
3064 This option is a combination of &%-bpr%& and &%-bpa%&.
3066 .vitem &%-bpru%&
3067 .oindex "&%-bpru%&"
3068 This option is a combination of &%-bpr%& and &%-bpu%&.
3071 .vitem &%-bpu%&
3072 .oindex "&%-bpu%&"
3073 This option operates like &%-bp%& but shows only undelivered top-level
3074 addresses for each message displayed. Addresses generated by aliasing or
3075 forwarding are not shown, unless the message was deferred after processing by a
3076 router with the &%one_time%& option set.
3079 .vitem &%-brt%&
3080 .oindex "&%-brt%&"
3081 .cindex "testing" "retry configuration"
3082 .cindex "retry" "configuration testing"
3083 This option is for testing retry rules, and it must be followed by up to three
3084 arguments. It causes Exim to look for a retry rule that matches the values
3085 and to write it to the standard output. For example:
3086 .code
3087 exim -brt bach.comp.mus.example
3088 Retry rule: *.comp.mus.example F,2h,15m; F,4d,30m;
3089 .endd
3090 See chapter &<<CHAPretry>>& for a description of Exim's retry rules. The first
3091 argument, which is required, can be a complete address in the form
3092 &'local_part@domain'&, or it can be just a domain name. If the second argument
3093 contains a dot, it is interpreted as an optional second domain name; if no
3094 retry rule is found for the first argument, the second is tried. This ties in
3095 with Exim's behaviour when looking for retry rules for remote hosts &-- if no
3096 rule is found that matches the host, one that matches the mail domain is
3097 sought. Finally, an argument that is the name of a specific delivery error, as
3098 used in setting up retry rules, can be given. For example:
3099 .code
3100 exim -brt haydn.comp.mus.example quota_3d
3101 Retry rule: *@haydn.comp.mus.example quota_3d F,1h,15m
3102 .endd
3104 .vitem &%-brw%&
3105 .oindex "&%-brw%&"
3106 .cindex "testing" "rewriting"
3107 .cindex "rewriting" "testing"
3108 This option is for testing address rewriting rules, and it must be followed by
3109 a single argument, consisting of either a local part without a domain, or a
3110 complete address with a fully qualified domain. Exim outputs how this address
3111 would be rewritten for each possible place it might appear. See chapter
3112 &<<CHAPrewrite>>& for further details.
3114 .vitem &%-bS%&
3115 .oindex "&%-bS%&"
3116 .cindex "SMTP" "batched incoming"
3117 .cindex "batched SMTP input"
3118 This option is used for batched SMTP input, which is an alternative interface
3119 for non-interactive local message submission. A number of messages can be
3120 submitted in a single run. However, despite its name, this is not really SMTP
3121 input. Exim reads each message's envelope from SMTP commands on the standard
3122 input, but generates no responses. If the caller is trusted, or
3123 &%untrusted_set_sender%& is set, the senders in the SMTP MAIL commands are
3124 believed; otherwise the sender is always the caller of Exim.
3126 The message itself is read from the standard input, in SMTP format (leading
3127 dots doubled), terminated by a line containing just a single dot. An error is
3128 provoked if the terminating dot is missing. A further message may then follow.
3130 As for other local message submissions, the contents of incoming batch SMTP
3131 messages can be checked using the non-SMTP ACL (see chapter &<<CHAPACL>>&).
3132 Unqualified addresses are automatically qualified using &%qualify_domain%& and
3133 &%qualify_recipient%&, as appropriate, unless the &%-bnq%& option is used.
3135 Some other SMTP commands are recognized in the input. HELO and EHLO act
3136 as RSET; VRFY, EXPN, ETRN, and HELP act as NOOP;
3137 QUIT quits, ignoring the rest of the standard input.
3139 .cindex "return code" "for &%-bS%&"
3140 If any error is encountered, reports are written to the standard output and
3141 error streams, and Exim gives up immediately. The return code is 0 if no error
3142 was detected; it is 1 if one or more messages were accepted before the error
3143 was detected; otherwise it is 2.
3145 More details of input using batched SMTP are given in section
3146 &<<SECTincomingbatchedSMTP>>&.
3148 .vitem &%-bs%&
3149 .oindex "&%-bs%&"
3150 .cindex "SMTP" "local input"
3151 .cindex "local SMTP input"
3152 This option causes Exim to accept one or more messages by reading SMTP commands
3153 on the standard input, and producing SMTP replies on the standard output. SMTP
3154 policy controls, as defined in ACLs (see chapter &<<CHAPACL>>&) are applied.
3155 Some user agents use this interface as a way of passing locally-generated
3156 messages to the MTA.
3158 In
3159 .cindex "sender" "source of"
3160 this usage, if the caller of Exim is trusted, or &%untrusted_set_sender%& is
3161 set, the senders of messages are taken from the SMTP MAIL commands.
3162 Otherwise the content of these commands is ignored and the sender is set up as
3163 the calling user. Unqualified addresses are automatically qualified using
3164 &%qualify_domain%& and &%qualify_recipient%&, as appropriate, unless the
3165 &%-bnq%& option is used.
3167 .cindex "inetd"
3168 The
3169 &%-bs%& option is also used to run Exim from &'inetd'&, as an alternative to
3170 using a listening daemon. Exim can distinguish the two cases by checking
3171 whether the standard input is a TCP/IP socket. When Exim is called from
3172 &'inetd'&, the source of the mail is assumed to be remote, and the comments
3173 above concerning senders and qualification do not apply. In this situation,
3174 Exim behaves in exactly the same way as it does when receiving a message via
3175 the listening daemon.
3177 .vitem &%-bmalware%&&~<&'filename'&>
3178 .oindex "&%-bmalware%&"
3179 .cindex "testing", "malware"
3180 .cindex "malware scan test"
3181 This debugging option causes Exim to scan the given file,
3182 using the malware scanning framework. The option of av_scanner influences
3183 this option, so if av_scanner's value is dependent upon an expansion then
3184 the expansion should have defaults which apply to this invocation. Exim will
3185 have changed working directory before resolving the filename, so using fully
3186 qualified pathnames is advisable. This option requires admin privileges.
3188 .vitem &%-bt%&
3189 .oindex "&%-bt%&"
3190 .cindex "testing" "addresses"
3191 .cindex "address" "testing"
3192 This option runs Exim in address testing mode, in which each argument is taken
3193 as a recipient address to be tested for deliverability. The results are
3194 written to the standard output. If a test fails, and the caller is not an admin
3195 user, no details of the failure are output, because these might contain
3196 sensitive information such as usernames and passwords for database lookups.
3198 If no arguments are given, Exim runs in an interactive manner, prompting with a
3199 right angle bracket for addresses to be tested.
3201 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3202 &[readline()]& function, because it is running as &'root'& and there are
3203 security issues.
3205 Each address is handled as if it were the recipient address of a message
3206 (compare the &%-bv%& option). It is passed to the routers and the result is
3207 written to the standard output. However, any router that has
3208 &%no_address_test%& set is bypassed. This can make &%-bt%& easier to use for
3209 genuine routing tests if your first router passes everything to a scanner
3210 program.
3212 .cindex "return code" "for &%-bt%&"
3213 The return code is 2 if any address failed outright; it is 1 if no address
3214 failed outright but at least one could not be resolved for some reason. Return
3215 code 0 is given only when all addresses succeed.
3217 .cindex "duplicate addresses"
3218 &*Note*&: When actually delivering a message, Exim removes duplicate recipient
3219 addresses after routing is complete, so that only one delivery takes place.
3220 This does not happen when testing with &%-bt%&; the full results of routing are
3221 always shown.
3223 &*Warning*&: &%-bt%& can only do relatively simple testing. If any of the
3224 routers in the configuration makes any tests on the sender address of a
3225 message,
3226 .oindex "&%-f%&" "for address testing"
3227 you can use the &%-f%& option to set an appropriate sender when running
3228 &%-bt%& tests. Without it, the sender is assumed to be the calling user at the
3229 default qualifying domain. However, if you have set up (for example) routers
3230 whose behaviour depends on the contents of an incoming message, you cannot test
3231 those conditions using &%-bt%&. The &%-N%& option provides a possible way of
3232 doing such tests.
3234 .vitem &%-bV%&
3235 .oindex "&%-bV%&"
3236 .cindex "version number of Exim"
3237 This option causes Exim to write the current version number, compilation
3238 number, and compilation date of the &'exim'& binary to the standard output.
3239 It also lists the DBM library this is being used, the optional modules (such as
3240 specific lookup types), the drivers that are included in the binary, and the
3241 name of the run time configuration file that is in use.
3243 As part of its operation, &%-bV%& causes Exim to read and syntax check its
3244 configuration file. However, this is a static check only. It cannot check
3245 values that are to be expanded. For example, although a misspelt ACL verb is
3246 detected, an error in the verb's arguments is not. You cannot rely on &%-bV%&
3247 alone to discover (for example) all the typos in the configuration; some
3248 realistic testing is needed. The &%-bh%& and &%-N%& options provide more
3249 dynamic testing facilities.
3251 .vitem &%-bv%&
3252 .oindex "&%-bv%&"
3253 .cindex "verifying address" "using &%-bv%&"
3254 .cindex "address" "verification"
3255 This option runs Exim in address verification mode, in which each argument is
3256 taken as a recipient address to be verified by the routers. (This does
3257 not involve any verification callouts). During normal operation, verification
3258 happens mostly as a consequence processing a &%verify%& condition in an ACL
3259 (see chapter &<<CHAPACL>>&). If you want to test an entire ACL, possibly
3260 including callouts, see the &%-bh%& and &%-bhc%& options.
3262 If verification fails, and the caller is not an admin user, no details of the
3263 failure are output, because these might contain sensitive information such as
3264 usernames and passwords for database lookups.
3266 If no arguments are given, Exim runs in an interactive manner, prompting with a
3267 right angle bracket for addresses to be verified.
3269 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3270 &[readline()]& function, because it is running as &'exim'& and there are
3271 security issues.
3273 Verification differs from address testing (the &%-bt%& option) in that routers
3274 that have &%no_verify%& set are skipped, and if the address is accepted by a
3275 router that has &%fail_verify%& set, verification fails. The address is
3276 verified as a recipient if &%-bv%& is used; to test verification for a sender
3277 address, &%-bvs%& should be used.
3279 If the &%-v%& option is not set, the output consists of a single line for each
3280 address, stating whether it was verified or not, and giving a reason in the
3281 latter case. Without &%-v%&, generating more than one address by redirection
3282 causes verification to end successfully, without considering the generated
3283 addresses. However, if just one address is generated, processing continues,
3284 and the generated address must verify successfully for the overall verification
3285 to succeed.
3287 When &%-v%& is set, more details are given of how the address has been handled,
3288 and in the case of address redirection, all the generated addresses are also
3289 considered. Verification may succeed for some and fail for others.
3291 The
3292 .cindex "return code" "for &%-bv%&"
3293 return code is 2 if any address failed outright; it is 1 if no address
3294 failed outright but at least one could not be resolved for some reason. Return
3295 code 0 is given only when all addresses succeed.
3297 If any of the routers in the configuration makes any tests on the sender
3298 address of a message, you should use the &%-f%& option to set an appropriate
3299 sender when running &%-bv%& tests. Without it, the sender is assumed to be the
3300 calling user at the default qualifying domain.
3302 .vitem &%-bvs%&
3303 .oindex "&%-bvs%&"
3304 This option acts like &%-bv%&, but verifies the address as a sender rather
3305 than a recipient address. This affects any rewriting and qualification that
3306 might happen.
3308 .vitem &%-C%&&~<&'filelist'&>
3309 .oindex "&%-C%&"
3310 .cindex "configuration file" "alternate"
3311 .cindex "CONFIGURE_FILE"
3312 .cindex "alternate configuration file"
3313 This option causes Exim to find the run time configuration file from the given
3314 list instead of from the list specified by the CONFIGURE_FILE
3315 compile-time setting. Usually, the list will consist of just a single file
3316 name, but it can be a colon-separated list of names. In this case, the first
3317 file that exists is used. Failure to open an existing file stops Exim from
3318 proceeding any further along the list, and an error is generated.
3320 When this option is used by a caller other than root or the Exim user, and the
3321 list is different from the compiled-in list, Exim gives up its root privilege
3322 immediately, and runs with the real and effective uid and gid set to those of
3323 the caller. However, if ALT_CONFIG_ROOT_ONLY is defined in
3324 &_Local/Makefile_&, root privilege is retained for &%-C%& only if the caller of
3325 Exim is root.
3327 That is, the Exim user is no longer privileged in this regard. This build-time
3328 option is not set by default in the Exim source distribution tarbundle.
3329 However, if you are using a &"packaged"& version of Exim (source or binary),
3330 the packagers might have enabled it.
3332 Setting ALT_CONFIG_ROOT_ONLY locks out the possibility of testing a
3333 configuration using &%-C%& right through message reception and delivery, even
3334 if the caller is root. The reception works, but by that time, Exim is running
3335 as the Exim user, so when it re-executes to regain privilege for the delivery,
3336 the use of &%-C%& causes privilege to be lost. However, root can test reception
3337 and delivery using two separate commands (one to put a message on the queue,
3338 using &%-odq%&, and another to do the delivery, using &%-M%&).
3340 If ALT_CONFIG_PREFIX is defined &_in Local/Makefile_&, it specifies a
3341 prefix string with which any file named in a &%-C%& command line option
3342 must start. In addition, the file name must not contain the sequence &`/../`&.
3343 However, if the value of the &%-C%& option is identical to the value of
3344 CONFIGURE_FILE in &_Local/Makefile_&, Exim ignores &%-C%& and proceeds as
3345 usual. There is no default setting for ALT_CONFIG_PREFIX; when it is
3346 unset, any file name can be used with &%-C%&.
3348 ALT_CONFIG_PREFIX can be used to confine alternative configuration files
3349 to a directory to which only root has access. This prevents someone who has
3350 broken into the Exim account from running a privileged Exim with an arbitrary
3351 configuration file.
3353 The &%-C%& facility is useful for ensuring that configuration files are
3354 syntactically correct, but cannot be used for test deliveries, unless the
3355 caller is privileged, or unless it is an exotic configuration that does not
3356 require privilege. No check is made on the owner or group of the files
3357 specified by this option.
3359 .vitem &%-D%&<&'macro'&>=<&'value'&>
3360 .oindex "&%-D%&"
3361 .cindex "macro" "setting on command line"
3362 This option can be used to override macro definitions in the configuration file
3363 (see section &<<SECTmacrodefs>>&). However, like &%-C%&, if it is used by an
3364 unprivileged caller, it causes Exim to give up its root privilege.
3365 If DISABLE_D_OPTION is defined in &_Local/Makefile_&, the use of &%-D%& is
3366 completely disabled, and its use causes an immediate error exit.
3368 The entire option (including equals sign if present) must all be within one
3369 command line item. &%-D%& can be used to set the value of a macro to the empty
3370 string, in which case the equals sign is optional. These two commands are
3371 synonymous:
3372 .code
3373 exim -DABC ...
3374 exim -DABC= ...
3375 .endd
3376 To include spaces in a macro definition item, quotes must be used. If you use
3377 quotes, spaces are permitted around the macro name and the equals sign. For
3378 example:
3379 .code
3380 exim '-D ABC = something' ...
3381 .endd
3382 &%-D%& may be repeated up to 10 times on a command line.
3384 .vitem &%-d%&<&'debug&~options'&>
3385 .oindex "&%-d%&"
3386 .cindex "debugging" "list of selectors"
3387 .cindex "debugging" "&%-d%& option"
3388 This option causes debugging information to be written to the standard
3389 error stream. It is restricted to admin users because debugging output may show
3390 database queries that contain password information. Also, the details of users'
3391 filter files should be protected. If a non-admin user uses &%-d%&, Exim
3392 writes an error message to the standard error stream and exits with a non-zero
3393 return code.
3395 When &%-d%& is used, &%-v%& is assumed. If &%-d%& is given on its own, a lot of
3396 standard debugging data is output. This can be reduced, or increased to include
3397 some more rarely needed information, by directly following &%-d%& with a string
3398 made up of names preceded by plus or minus characters. These add or remove sets
3399 of debugging data, respectively. For example, &%-d+filter%& adds filter
3400 debugging, whereas &%-d-all+filter%& selects only filter debugging. Note that
3401 no spaces are allowed in the debug setting. The available debugging categories
3402 are:
3403 .display
3404 &`acl `& ACL interpretation
3405 &`auth `& authenticators
3406 &`deliver `& general delivery logic
3407 &`dns `& DNS lookups (see also resolver)
3408 &`dnsbl `& DNS black list (aka RBL) code
3409 &`exec `& arguments for &[execv()]& calls
3410 &`expand `& detailed debugging for string expansions
3411 &`filter `& filter handling
3412 &`hints_lookup `& hints data lookups
3413 &`host_lookup `& all types of name-to-IP address handling
3414 &`ident `& ident lookup
3415 &`interface `& lists of local interfaces
3416 &`lists `& matching things in lists
3417 &`load `& system load checks
3418 &`local_scan `& can be used by &[local_scan()]& (see chapter &&&
3419 &<<CHAPlocalscan>>&)
3420 &`lookup `& general lookup code and all lookups
3421 &`memory `& memory handling
3422 &`pid `& add pid to debug output lines
3423 &`process_info `& setting info for the process log
3424 &`queue_run `& queue runs
3425 &`receive `& general message reception logic
3426 &`resolver `& turn on the DNS resolver's debugging output
3427 &`retry `& retry handling
3428 &`rewrite `& address rewriting
3429 &`route `& address routing
3430 &`timestamp `& add timestamp to debug output lines
3431 &`tls `& TLS logic
3432 &`transport `& transports
3433 &`uid `& changes of uid/gid and looking up uid/gid
3434 &`verify `& address verification logic
3435 &`all `& almost all of the above (see below), and also &%-v%&
3436 .endd
3437 The &`all`& option excludes &`memory`& when used as &`+all`&, but includes it
3438 for &`-all`&. The reason for this is that &`+all`& is something that people
3439 tend to use when generating debug output for Exim maintainers. If &`+memory`&
3440 is included, an awful lot of output that is very rarely of interest is
3441 generated, so it now has to be explicitly requested. However, &`-all`& does
3442 turn everything off.
3444 .cindex "resolver, debugging output"
3445 .cindex "DNS resolver, debugging output"
3446 The &`resolver`& option produces output only if the DNS resolver was compiled
3447 with DEBUG enabled. This is not the case in some operating systems. Also,
3448 unfortunately, debugging output from the DNS resolver is written to stdout
3449 rather than stderr.
3451 The default (&%-d%& with no argument) omits &`expand`&, &`filter`&,
3452 &`interface`&, &`load`&, &`memory`&, &`pid`&, &`resolver`&, and &`timestamp`&.
3453 However, the &`pid`& selector is forced when debugging is turned on for a
3454 daemon, which then passes it on to any re-executed Exims. Exim also
3455 automatically adds the pid to debug lines when several remote deliveries are
3456 run in parallel.
3458 The &`timestamp`& selector causes the current time to be inserted at the start
3459 of all debug output lines. This can be useful when trying to track down delays
3460 in processing.
3462 If the &%debug_print%& option is set in any driver, it produces output whenever
3463 any debugging is selected, or if &%-v%& is used.
3465 .vitem &%-dd%&<&'debug&~options'&>
3466 .oindex "&%-dd%&"
3467 This option behaves exactly like &%-d%& except when used on a command that
3468 starts a daemon process. In that case, debugging is turned off for the
3469 subprocesses that the daemon creates. Thus, it is useful for monitoring the
3470 behaviour of the daemon without creating as much output as full debugging does.
3472 .vitem &%-dropcr%&
3473 .oindex "&%-dropcr%&"
3474 This is an obsolete option that is now a no-op. It used to affect the way Exim
3475 handled CR and LF characters in incoming messages. What happens now is
3476 described in section &<<SECTlineendings>>&.
3478 .vitem &%-E%&
3479 .oindex "&%-E%&"
3480 .cindex "bounce message" "generating"
3481 This option specifies that an incoming message is a locally-generated delivery
3482 failure report. It is used internally by Exim when handling delivery failures
3483 and is not intended for external use. Its only effect is to stop Exim
3484 generating certain messages to the postmaster, as otherwise message cascades
3485 could occur in some situations. As part of the same option, a message id may
3486 follow the characters &%-E%&. If it does, the log entry for the receipt of the
3487 new message contains the id, following &"R="&, as a cross-reference.
3489 .vitem &%-e%&&'x'&
3490 .oindex "&%-e%&&'x'&"
3491 There are a number of Sendmail options starting with &%-oe%& which seem to be
3492 called by various programs without the leading &%o%& in the option. For
3493 example, the &%vacation%& program uses &%-eq%&. Exim treats all options of the
3494 form &%-e%&&'x'& as synonymous with the corresponding &%-oe%&&'x'& options.
3496 .vitem &%-F%&&~<&'string'&>
3497 .oindex "&%-F%&"
3498 .cindex "sender" "name"
3499 .cindex "name" "of sender"
3500 This option sets the sender's full name for use when a locally-generated
3501 message is being accepted. In the absence of this option, the user's &'gecos'&
3502 entry from the password data is used. As users are generally permitted to alter
3503 their &'gecos'& entries, no security considerations are involved. White space
3504 between &%-F%& and the <&'string'&> is optional.
3506 .vitem &%-f%&&~<&'address'&>
3507 .oindex "&%-f%&"
3508 .cindex "sender" "address"
3509 .cindex "address" "sender"
3510 .cindex "trusted users"
3511 .cindex "envelope sender"
3512 .cindex "user" "trusted"
3513 This option sets the address of the envelope sender of a locally-generated
3514 message (also known as the return path). The option can normally be used only
3515 by a trusted user, but &%untrusted_set_sender%& can be set to allow untrusted
3516 users to use it.
3518 Processes running as root or the Exim user are always trusted. Other
3519 trusted users are defined by the &%trusted_users%& or &%trusted_groups%&
3520 options. In the absence of &%-f%&, or if the caller is not trusted, the sender
3521 of a local message is set to the caller's login name at the default qualify
3522 domain.
3524 There is one exception to the restriction on the use of &%-f%&: an empty sender
3525 can be specified by any user, trusted or not, to create a message that can
3526 never provoke a bounce. An empty sender can be specified either as an empty
3527 string, or as a pair of angle brackets with nothing between them, as in these
3528 examples of shell commands:
3529 .code
3530 exim -f '<>' user@domain
3531 exim -f "" user@domain
3532 .endd
3533 In addition, the use of &%-f%& is not restricted when testing a filter file
3534 with &%-bf%& or when testing or verifying addresses using the &%-bt%& or
3535 &%-bv%& options.
3537 Allowing untrusted users to change the sender address does not of itself make
3538 it possible to send anonymous mail. Exim still checks that the &'From:'& header
3539 refers to the local user, and if it does not, it adds a &'Sender:'& header,
3540 though this can be overridden by setting &%no_local_from_check%&.
3542 White
3543 .cindex "&""From""& line"
3544 space between &%-f%& and the <&'address'&> is optional (that is, they can be
3545 given as two arguments or one combined argument). The sender of a
3546 locally-generated message can also be set (when permitted) by an initial
3547 &"From&~"& line in the message &-- see the description of &%-bm%& above &-- but
3548 if &%-f%& is also present, it overrides &"From&~"&.
3550 .vitem &%-G%&
3551 .oindex "&%-G%&"
3552 .cindex "Sendmail compatibility" "&%-G%& option ignored"
3553 This is a Sendmail option which is ignored by Exim.
3555 .vitem &%-h%&&~<&'number'&>
3556 .oindex "&%-h%&"
3557 .cindex "Sendmail compatibility" "&%-h%& option ignored"
3558 This option is accepted for compatibility with Sendmail, but has no effect. (In
3559 Sendmail it overrides the &"hop count"& obtained by counting &'Received:'&
3560 headers.)
3562 .vitem &%-i%&
3563 .oindex "&%-i%&"
3564 .cindex "Solaris" "&'mail'& command"
3565 .cindex "dot" "in incoming non-SMTP message"
3566 This option, which has the same effect as &%-oi%&, specifies that a dot on a
3567 line by itself should not terminate an incoming, non-SMTP message. I can find
3568 no documentation for this option in Solaris 2.4 Sendmail, but the &'mailx'&
3569 command in Solaris 2.4 uses it. See also &%-ti%&.
3571 .vitem &%-M%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3572 .oindex "&%-M%&"
3573 .cindex "forcing delivery"
3574 .cindex "delivery" "forcing attempt"
3575 .cindex "frozen messages" "forcing delivery"
3576 This option requests Exim to run a delivery attempt on each message in turn. If
3577 any of the messages are frozen, they are automatically thawed before the
3578 delivery attempt. The settings of &%queue_domains%&, &%queue_smtp_domains%&,
3579 and &%hold_domains%& are ignored.
3581 Retry
3582 .cindex "hints database" "overriding retry hints"
3583 hints for any of the addresses are overridden &-- Exim tries to deliver even if
3584 the normal retry time has not yet been reached. This option requires the caller
3585 to be an admin user. However, there is an option called &%prod_requires_admin%&
3586 which can be set false to relax this restriction (and also the same requirement
3587 for the &%-q%&, &%-R%&, and &%-S%& options).
3589 The deliveries happen synchronously, that is, the original Exim process does
3590 not terminate until all the delivery attempts have finished. No output is
3591 produced unless there is a serious error. If you want to see what is happening,
3592 use the &%-v%& option as well, or inspect Exim's main log.
3594 .vitem &%-Mar%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
3595 .oindex "&%-Mar%&"
3596 .cindex "message" "adding recipients"
3597 .cindex "recipient" "adding"
3598 This option requests Exim to add the addresses to the list of recipients of the
3599 message (&"ar"& for &"add recipients"&). The first argument must be a message
3600 id, and the remaining ones must be email addresses. However, if the message is
3601 active (in the middle of a delivery attempt), it is not altered. This option
3602 can be used only by an admin user.
3604 .vitem "&%-MC%&&~<&'transport'&>&~<&'hostname'&>&~<&'sequence&~number'&>&&&
3605 &~<&'message&~id'&>"
3606 .oindex "&%-MC%&"
3607 .cindex "SMTP" "passed connection"
3608 .cindex "SMTP" "multiple deliveries"
3609 .cindex "multiple SMTP deliveries"
3610 This option is not intended for use by external callers. It is used internally
3611 by Exim to invoke another instance of itself to deliver a waiting message using
3612 an existing SMTP connection, which is passed as the standard input. Details are
3613 given in chapter &<<CHAPSMTP>>&. This must be the final option, and the caller
3614 must be root or the Exim user in order to use it.
3616 .vitem &%-MCA%&
3617 .oindex "&%-MCA%&"
3618 This option is not intended for use by external callers. It is used internally
3619 by Exim in conjunction with the &%-MC%& option. It signifies that the
3620 connection to the remote host has been authenticated.
3622 .vitem &%-MCP%&
3623 .oindex "&%-MCP%&"
3624 This option is not intended for use by external callers. It is used internally
3625 by Exim in conjunction with the &%-MC%& option. It signifies that the server to
3626 which Exim is connected supports pipelining.
3628 .vitem &%-MCQ%&&~<&'process&~id'&>&~<&'pipe&~fd'&>
3629 .oindex "&%-MCQ%&"
3630 This option is not intended for use by external callers. It is used internally
3631 by Exim in conjunction with the &%-MC%& option when the original delivery was
3632 started by a queue runner. It passes on the process id of the queue runner,
3633 together with the file descriptor number of an open pipe. Closure of the pipe
3634 signals the final completion of the sequence of processes that are passing
3635 messages through the same SMTP connection.
3637 .vitem &%-MCS%&
3638 .oindex "&%-MCS%&"
3639 This option is not intended for use by external callers. It is used internally
3640 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3641 SMTP SIZE option should be used on messages delivered down the existing
3642 connection.
3644 .vitem &%-MCT%&
3645 .oindex "&%-MCT%&"
3646 This option is not intended for use by external callers. It is used internally
3647 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3648 host to which Exim is connected supports TLS encryption.
3650 .vitem &%-Mc%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3651 .oindex "&%-Mc%&"
3652 .cindex "hints database" "not overridden by &%-Mc%&"
3653 .cindex "delivery" "manually started &-- not forced"
3654 This option requests Exim to run a delivery attempt on each message in turn,
3655 but unlike the &%-M%& option, it does check for retry hints, and respects any
3656 that are found. This option is not very useful to external callers. It is
3657 provided mainly for internal use by Exim when it needs to re-invoke itself in
3658 order to regain root privilege for a delivery (see chapter &<<CHAPsecurity>>&).
3659 However, &%-Mc%& can be useful when testing, in order to run a delivery that
3660 respects retry times and other options such as &%hold_domains%& that are
3661 overridden when &%-M%& is used. Such a delivery does not count as a queue run.
3662 If you want to run a specific delivery as if in a queue run, you should use
3663 &%-q%& with a message id argument. A distinction between queue run deliveries
3664 and other deliveries is made in one or two places.
3666 .vitem &%-Mes%&&~<&'message&~id'&>&~<&'address'&>
3667 .oindex "&%-Mes%&"
3668 .cindex "message" "changing sender"
3669 .cindex "sender" "changing"
3670 This option requests Exim to change the sender address in the message to the
3671 given address, which must be a fully qualified address or &"<>"& (&"es"& for
3672 &"edit sender"&). There must be exactly two arguments. The first argument must
3673 be a message id, and the second one an email address. However, if the message
3674 is active (in the middle of a delivery attempt), its status is not altered.
3675 This option can be used only by an admin user.
3677 .vitem &%-Mf%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3678 .oindex "&%-Mf%&"
3679 .cindex "freezing messages"
3680 .cindex "message" "manually freezing"
3681 This option requests Exim to mark each listed message as &"frozen"&. This
3682 prevents any delivery attempts taking place until the message is &"thawed"&,
3683 either manually or as a result of the &%auto_thaw%& configuration option.
3684 However, if any of the messages are active (in the middle of a delivery
3685 attempt), their status is not altered. This option can be used only by an admin
3686 user.
3688 .vitem &%-Mg%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3689 .oindex "&%-Mg%&"
3690 .cindex "giving up on messages"
3691 .cindex "message" "abandoning delivery attempts"
3692 .cindex "delivery" "abandoning further attempts"
3693 This option requests Exim to give up trying to deliver the listed messages,
3694 including any that are frozen. However, if any of the messages are active,
3695 their status is not altered. For non-bounce messages, a delivery error message
3696 is sent to the sender, containing the text &"cancelled by administrator"&.
3697 Bounce messages are just discarded. This option can be used only by an admin
3698 user.
3700 .vitem &%-Mmad%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3701 .oindex "&%-Mmad%&"
3702 .cindex "delivery" "cancelling all"
3703 This option requests Exim to mark all the recipient addresses in the messages
3704 as already delivered (&"mad"& for &"mark all delivered"&). However, if any
3705 message is active (in the middle of a delivery attempt), its status is not
3706 altered. This option can be used only by an admin user.
3708 .vitem &%-Mmd%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
3709 .oindex "&%-Mmd%&"
3710 .cindex "delivery" "cancelling by address"
3711 .cindex "recipient" "removing"
3712 .cindex "removing recipients"
3713 This option requests Exim to mark the given addresses as already delivered
3714 (&"md"& for &"mark delivered"&). The first argument must be a message id, and
3715 the remaining ones must be email addresses. These are matched to recipient
3716 addresses in the message in a case-sensitive manner. If the message is active
3717 (in the middle of a delivery attempt), its status is not altered. This option
3718 can be used only by an admin user.
3720 .vitem &%-Mrm%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3721 .oindex "&%-Mrm%&"
3722 .cindex "removing messages"
3723 .cindex "abandoning mail"
3724 .cindex "message" "manually discarding"
3725 This option requests Exim to remove the given messages from the queue. No
3726 bounce messages are sent; each message is simply forgotten. However, if any of
3727 the messages are active, their status is not altered. This option can be used
3728 only by an admin user or by the user who originally caused the message to be
3729 placed on the queue.
3731 .vitem &%-Mset%&&~<&'message&~id'&>
3732 .oindex "&%-Mset%&
3733 .cindex "testing" "string expansion"
3734 .cindex "expansion" "testing"
3735 This option is useful only in conjunction with &%-be%& (that is, when testing
3736 string expansions). Exim loads the given message from its spool before doing
3737 the test expansions, thus setting message-specific variables such as
3738 &$message_size$& and the header variables. The &$recipients$& variable is made
3739 available. This feature is provided to make it easier to test expansions that
3740 make use of these variables. However, this option can be used only by an admin
3741 user. See also &%-bem%&.
3743 .vitem &%-Mt%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3744 .oindex "&%-Mt%&"
3745 .cindex "thawing messages"
3746 .cindex "unfreezing messages"
3747 .cindex "frozen messages" "thawing"
3748 .cindex "message" "thawing frozen"
3749 This option requests Exim to &"thaw"& any of the listed messages that are
3750 &"frozen"&, so that delivery attempts can resume. However, if any of the
3751 messages are active, their status is not altered. This option can be used only
3752 by an admin user.
3754 .vitem &%-Mvb%&&~<&'message&~id'&>
3755 .oindex "&%-Mvb%&"
3756 .cindex "listing" "message body"
3757 .cindex "message" "listing body of"
3758 This option causes the contents of the message body (-D) spool file to be
3759 written to the standard output. This option can be used only by an admin user.
3761 .vitem &%-Mvc%&&~<&'message&~id'&>
3762 .oindex "&%-Mvc%&"
3763 .cindex "message" "listing in RFC 2822 format"
3764 .cindex "listing" "message in RFC 2822 format"
3765 This option causes a copy of the complete message (header lines plus body) to
3766 be written to the standard output in RFC 2822 format. This option can be used
3767 only by an admin user.
3769 .vitem &%-Mvh%&&~<&'message&~id'&>
3770 .oindex "&%-Mvh%&"
3771 .cindex "listing" "message headers"
3772 .cindex "header lines" "listing"
3773 .cindex "message" "listing header lines"
3774 This option causes the contents of the message headers (-H) spool file to be
3775 written to the standard output. This option can be used only by an admin user.
3777 .vitem &%-Mvl%&&~<&'message&~id'&>
3778 .oindex "&%-Mvl%&"
3779 .cindex "listing" "message log"
3780 .cindex "message" "listing message log"
3781 This option causes the contents of the message log spool file to be written to
3782 the standard output. This option can be used only by an admin user.
3784 .vitem &%-m%&
3785 .oindex "&%-m%&"
3786 This is apparently a synonym for &%-om%& that is accepted by Sendmail, so Exim
3787 treats it that way too.
3789 .vitem &%-N%&
3790 .oindex "&%-N%&"
3791 .cindex "debugging" "&%-N%& option"
3792 .cindex "debugging" "suppressing delivery"
3793 This is a debugging option that inhibits delivery of a message at the transport
3794 level. It implies &%-v%&. Exim goes through many of the motions of delivery &--
3795 it just doesn't actually transport the message, but instead behaves as if it
3796 had successfully done so. However, it does not make any updates to the retry
3797 database, and the log entries for deliveries are flagged with &"*>"& rather
3798 than &"=>"&.
3800 Because &%-N%& discards any message to which it applies, only root or the Exim
3801 user are allowed to use it with &%-bd%&, &%-q%&, &%-R%& or &%-M%&. In other
3802 words, an ordinary user can use it only when supplying an incoming message to
3803 which it will apply. Although transportation never fails when &%-N%& is set, an
3804 address may be deferred because of a configuration problem on a transport, or a
3805 routing problem. Once &%-N%& has been used for a delivery attempt, it sticks to
3806 the message, and applies to any subsequent delivery attempts that may happen
3807 for that message.
3809 .vitem &%-n%&
3810 .oindex "&%-n%&"
3811 .cindex "Sendmail compatibility" "&%-n%& option ignored"
3812 This option is interpreted by Sendmail to mean &"no aliasing"&. It is ignored
3813 by Exim.
3815 .vitem &%-O%&&~<&'data'&>
3816 .oindex "&%-O%&"
3817 This option is interpreted by Sendmail to mean &`set option`&. It is ignored by
3818 Exim.
3820 .vitem &%-oA%&&~<&'file&~name'&>
3821 .oindex "&%-oA%&"
3822 .cindex "Sendmail compatibility" "&%-oA%& option"
3823 This option is used by Sendmail in conjunction with &%-bi%& to specify an
3824 alternative alias file name. Exim handles &%-bi%& differently; see the
3825 description above.
3827 .vitem &%-oB%&&~<&'n'&>
3828 .oindex "&%-oB%&"
3829 .cindex "SMTP" "passed connection"
3830 .cindex "SMTP" "multiple deliveries"
3831 .cindex "multiple SMTP deliveries"
3832 This is a debugging option which limits the maximum number of messages that can
3833 be delivered down one SMTP connection, overriding the value set in any &(smtp)&
3834 transport. If <&'n'&> is omitted, the limit is set to 1.
3836 .vitem &%-odb%&
3837 .oindex "&%-odb%&"
3838 .cindex "background delivery"
3839 .cindex "delivery" "in the background"
3840 This option applies to all modes in which Exim accepts incoming messages,
3841 including the listening daemon. It requests &"background"& delivery of such
3842 messages, which means that the accepting process automatically starts a
3843 delivery process for each message received, but does not wait for the delivery
3844 processes to finish.
3846 When all the messages have been received, the reception process exits,
3847 leaving the delivery processes to finish in their own time. The standard output
3848 and error streams are closed at the start of each delivery process.
3849 This is the default action if none of the &%-od%& options are present.
3851 If one of the queueing options in the configuration file
3852 (&%queue_only%& or &%queue_only_file%&, for example) is in effect, &%-odb%&
3853 overrides it if &%queue_only_override%& is set true, which is the default
3854 setting. If &%queue_only_override%& is set false, &%-odb%& has no effect.
3856 .vitem &%-odf%&
3857 .oindex "&%-odf%&"
3858 .cindex "foreground delivery"
3859 .cindex "delivery" "in the foreground"
3860 This option requests &"foreground"& (synchronous) delivery when Exim has
3861 accepted a locally-generated message. (For the daemon it is exactly the same as
3862 &%-odb%&.) A delivery process is automatically started to deliver the message,
3863 and Exim waits for it to complete before proceeding.
3865 The original Exim reception process does not finish until the delivery
3866 process for the final message has ended. The standard error stream is left open
3867 during deliveries.
3869 However, like &%-odb%&, this option has no effect if &%queue_only_override%& is
3870 false and one of the queueing options in the configuration file is in effect.
3872 If there is a temporary delivery error during foreground delivery, the
3873 message is left on the queue for later delivery, and the original reception
3874 process exits. See chapter &<<CHAPnonqueueing>>& for a way of setting up a
3875 restricted configuration that never queues messages.
3878 .vitem &%-odi%&
3879 .oindex "&%-odi%&"
3880 This option is synonymous with &%-odf%&. It is provided for compatibility with
3881 Sendmail.
3883 .vitem &%-odq%&
3884 .oindex "&%-odq%&"
3885 .cindex "non-immediate delivery"
3886 .cindex "delivery" "suppressing immediate"
3887 .cindex "queueing incoming messages"
3888 This option applies to all modes in which Exim accepts incoming messages,
3889 including the listening daemon. It specifies that the accepting process should
3890 not automatically start a delivery process for each message received. Messages
3891 are placed on the queue, and remain there until a subsequent queue runner
3892 process encounters them. There are several configuration options (such as
3893 &%queue_only%&) that can be used to queue incoming messages under certain
3894 conditions. This option overrides all of them and also &%-odqs%&. It always
3895 forces queueing.
3897 .vitem &%-odqs%&
3898 .oindex "&%-odqs%&"
3899 .cindex "SMTP" "delaying delivery"
3900 This option is a hybrid between &%-odb%&/&%-odi%& and &%-odq%&.
3901 However, like &%-odb%& and &%-odi%&, this option has no effect if
3902 &%queue_only_override%& is false and one of the queueing options in the
3903 configuration file is in effect.
3905 When &%-odqs%& does operate, a delivery process is started for each incoming
3906 message, in the background by default, but in the foreground if &%-odi%& is
3907 also present. The recipient addresses are routed, and local deliveries are done
3908 in the normal way. However, if any SMTP deliveries are required, they are not
3909 done at this time, so the message remains on the queue until a subsequent queue
3910 runner process encounters it. Because routing was done, Exim knows which
3911 messages are waiting for which hosts, and so a number of messages for the same
3912 host can be sent in a single SMTP connection. The &%queue_smtp_domains%&
3913 configuration option has the same effect for specific domains. See also the
3914 &%-qq%& option.
3916 .vitem &%-oee%&
3917 .oindex "&%-oee%&"
3918 .cindex "error" "reporting"
3919 If an error is detected while a non-SMTP message is being received (for
3920 example, a malformed address), the error is reported to the sender in a mail
3921 message.
3923 .cindex "return code" "for &%-oee%&"
3924 Provided
3925 this error message is successfully sent, the Exim receiving process
3926 exits with a return code of zero. If not, the return code is 2 if the problem
3927 is that the original message has no recipients, or 1 any other error. This is
3928 the default &%-oe%&&'x'& option if Exim is called as &'rmail'&.
3930 .vitem &%-oem%&
3931 .oindex "&%-oem%&"
3932 .cindex "error" "reporting"
3933 .cindex "return code" "for &%-oem%&"
3934 This is the same as &%-oee%&, except that Exim always exits with a non-zero
3935 return code, whether or not the error message was successfully sent.
3936 This is the default &%-oe%&&'x'& option, unless Exim is called as &'rmail'&.
3938 .vitem &%-oep%&
3939 .oindex "&%-oep%&"
3940 .cindex "error" "reporting"
3941 If an error is detected while a non-SMTP message is being received, the
3942 error is reported by writing a message to the standard error file (stderr).
3943 .cindex "return code" "for &%-oep%&"
3944 The return code is 1 for all errors.
3946 .vitem &%-oeq%&
3947 .oindex "&%-oeq%&"
3948 .cindex "error" "reporting"
3949 This option is supported for compatibility with Sendmail, but has the same
3950 effect as &%-oep%&.
3952 .vitem &%-oew%&
3953 .oindex "&%-oew%&"
3954 .cindex "error" "reporting"
3955 This option is supported for compatibility with Sendmail, but has the same
3956 effect as &%-oem%&.
3958 .vitem &%-oi%&
3959 .oindex "&%-oi%&"
3960 .cindex "dot" "in incoming non-SMTP message"
3961 This option, which has the same effect as &%-i%&, specifies that a dot on a
3962 line by itself should not terminate an incoming, non-SMTP message. Otherwise, a
3963 single dot does terminate, though Exim does no special processing for other
3964 lines that start with a dot. This option is set by default if Exim is called as
3965 &'rmail'&. See also &%-ti%&.
3967 .vitem &%-oitrue%&
3968 .oindex "&%-oitrue%&"
3969 This option is treated as synonymous with &%-oi%&.
3971 .vitem &%-oMa%&&~<&'host&~address'&>
3972 .oindex "&%-oMa%&"
3973 .cindex "sender" "host address, specifying for local message"
3974 A number of options starting with &%-oM%& can be used to set values associated
3975 with remote hosts on locally-submitted messages (that is, messages not received
3976 over TCP/IP). These options can be used by any caller in conjunction with the
3977 &%-bh%&, &%-be%&, &%-bf%&, &%-bF%&, &%-bt%&, or &%-bv%& testing options. In
3978 other circumstances, they are ignored unless the caller is trusted.
3980 The &%-oMa%& option sets the sender host address. This may include a port
3981 number at the end, after a full stop (period). For example:
3982 .code
3983 exim -bs -oMa
3984 .endd
3985 An alternative syntax is to enclose the IP address in square brackets,
3986 followed by a colon and the port number:
3987 .code
3988 exim -bs -oMa []:1234
3989 .endd
3990 The IP address is placed in the &$sender_host_address$& variable, and the
3991 port, if present, in &$sender_host_port$&. If both &%-oMa%& and &%-bh%&
3992 are present on the command line, the sender host IP address is taken from
3993 whichever one is last.
3995 .vitem &%-oMaa%&&~<&'name'&>
3996 .oindex "&%-oMaa%&"
3997 .cindex "authentication" "name, specifying for local message"
3998 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMaa%&
3999 option sets the value of &$sender_host_authenticated$& (the authenticator
4000 name). See chapter &<<CHAPSMTPAUTH>>& for a discussion of SMTP authentication.
4001 This option can be used with &%-bh%& and &%-bs%& to set up an
4002 authenticated SMTP session without actually using the SMTP AUTH command.
4004 .vitem &%-oMai%&&~<&'string'&>
4005 .oindex "&%-oMai%&"
4006 .cindex "authentication" "id, specifying for local message"
4007 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMai%&
4008 option sets the value of &$authenticated_id$& (the id that was authenticated).
4009 This overrides the default value (the caller's login id, except with &%-bh%&,
4010 where there is no default) for messages from local sources. See chapter
4011 &<<CHAPSMTPAUTH>>& for a discussion of authenticated ids.
4013 .vitem &%-oMas%&&~<&'address'&>
4014 .oindex "&%-oMas%&"
4015 .cindex "authentication" "sender, specifying for local message"
4016 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMas%&
4017 option sets the authenticated sender value in &$authenticated_sender$&. It
4018 overrides the sender address that is created from the caller's login id for
4019 messages from local sources, except when &%-bh%& is used, when there is no
4020 default. For both &%-bh%& and &%-bs%&, an authenticated sender that is
4021 specified on a MAIL command overrides this value. See chapter
4022 &<<CHAPSMTPAUTH>>& for a discussion of authenticated senders.
4024 .vitem &%-oMi%&&~<&'interface&~address'&>
4025 .oindex "&%-oMi%&"
4026 .cindex "interface" "address, specifying for local message"
4027 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMi%&
4028 option sets the IP interface address value. A port number may be included,
4029 using the same syntax as for &%-oMa%&. The interface address is placed in
4030 &$received_ip_address$& and the port number, if present, in &$received_port$&.
4032 .vitem &%-oMr%&&~<&'protocol&~name'&>
4033 .oindex "&%-oMr%&"
4034 .cindex "protocol, specifying for local message"
4035 .vindex "&$received_protocol$&"
4036 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMr%&
4037 option sets the received protocol value that is stored in
4038 &$received_protocol$&. However, it does not apply (and is ignored) when &%-bh%&
4039 or &%-bs%& is used. For &%-bh%&, the protocol is forced to one of the standard
4040 SMTP protocol names (see the description of &$received_protocol$& in section
4041 &<<SECTexpvar>>&). For &%-bs%&, the protocol is always &"local-"& followed by
4042 one of those same names. For &%-bS%& (batched SMTP) however, the protocol can
4043 be set by &%-oMr%&.
4045 .vitem &%-oMs%&&~<&'host&~name'&>
4046 .oindex "&%-oMs%&"
4047 .cindex "sender" "host name, specifying for local message"
4048 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMs%&
4049 option sets the sender host name in &$sender_host_name$&. When this option is
4050 present, Exim does not attempt to look up a host name from an IP address; it
4051 uses the name it is given.
4053 .vitem &%-oMt%&&~<&'ident&~string'&>
4054 .oindex "&%-oMt%&"
4055 .cindex "sender" "ident string, specifying for local message"
4056 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMt%&
4057 option sets the sender ident value in &$sender_ident$&. The default setting for
4058 local callers is the login id of the calling process, except when &%-bh%& is
4059 used, when there is no default.
4061 .vitem &%-om%&
4062 .oindex "&%-om%&"
4063 .cindex "Sendmail compatibility" "&%-om%& option ignored"
4064 In Sendmail, this option means &"me too"&, indicating that the sender of a
4065 message should receive a copy of the message if the sender appears in an alias
4066 expansion. Exim always does this, so the option does nothing.
4068 .vitem &%-oo%&
4069 .oindex "&%-oo%&"
4070 .cindex "Sendmail compatibility" "&%-oo%& option ignored"
4071 This option is ignored. In Sendmail it specifies &"old style headers"&,
4072 whatever that means.
4074 .vitem &%-oP%&&~<&'path'&>
4075 .oindex "&%-oP%&"
4076 .cindex "pid (process id)" "of daemon"
4077 .cindex "daemon" "process id (pid)"
4078 This option is useful only in conjunction with &%-bd%& or &%-q%& with a time
4079 value. The option specifies the file to which the process id of the daemon is
4080 written. When &%-oX%& is used with &%-bd%&, or when &%-q%& with a time is used
4081 without &%-bd%&, this is the only way of causing Exim to write a pid file,
4082 because in those cases, the normal pid file is not used.
4084 .vitem &%-or%&&~<&'time'&>
4085 .oindex "&%-or%&"
4086 .cindex "timeout" "for non-SMTP input"
4087 This option sets a timeout value for incoming non-SMTP messages. If it is not
4088 set, Exim will wait forever for the standard input. The value can also be set
4089 by the &%receive_timeout%& option. The format used for specifying times is
4090 described in section &<<SECTtimeformat>>&.
4092 .vitem &%-os%&&~<&'time'&>
4093 .oindex "&%-os%&"
4094 .cindex "timeout" "for SMTP input"
4095 .cindex "SMTP" "input timeout"
4096 This option sets a timeout value for incoming SMTP messages. The timeout
4097 applies to each SMTP command and block of data. The value can also be set by
4098 the &%smtp_receive_timeout%& option; it defaults to 5 minutes. The format used
4099 for specifying times is described in section &<<SECTtimeformat>>&.
4101 .vitem &%-ov%&
4102 .oindex "&%-ov%&"
4103 This option has exactly the same effect as &%-v%&.
4105 .vitem &%-oX%&&~<&'number&~or&~string'&>
4106 .oindex "&%-oX%&"
4107 .cindex "TCP/IP" "setting listening ports"
4108 .cindex "TCP/IP" "setting listening interfaces"
4109 .cindex "port" "receiving TCP/IP"
4110 This option is relevant only when the &%-bd%& (start listening daemon) option
4111 is also given. It controls which ports and interfaces the daemon uses. Details
4112 of the syntax, and how it interacts with configuration file options, are given
4113 in chapter &<<CHAPinterfaces>>&. When &%-oX%& is used to start a daemon, no pid
4114 file is written unless &%-oP%& is also present to specify a pid file name.
4116 .vitem &%-pd%&
4117 .oindex "&%-pd%&"
4118 .cindex "Perl" "starting the interpreter"
4119 This option applies when an embedded Perl interpreter is linked with Exim (see
4120 chapter &<<CHAPperl>>&). It overrides the setting of the &%perl_at_start%&
4121 option, forcing the starting of the interpreter to be delayed until it is
4122 needed.
4124 .vitem &%-ps%&
4125 .oindex "&%-ps%&"
4126 .cindex "Perl" "starting the interpreter"
4127 This option applies when an embedded Perl interpreter is linked with Exim (see
4128 chapter &<<CHAPperl>>&). It overrides the setting of the &%perl_at_start%&
4129 option, forcing the starting of the interpreter to occur as soon as Exim is
4130 started.
4132 .vitem &%-p%&<&'rval'&>:<&'sval'&>
4133 .oindex "&%-p%&"
4134 For compatibility with Sendmail, this option is equivalent to
4135 .display
4136 &`-oMr`& <&'rval'&> &`-oMs`& <&'sval'&>
4137 .endd
4138 It sets the incoming protocol and host name (for trusted callers). The
4139 host name and its colon can be omitted when only the protocol is to be set.
4140 Note the Exim already has two private options, &%-pd%& and &%-ps%&, that refer
4141 to embedded Perl. It is therefore impossible to set a protocol value of &`p`&
4142 or &`s`& using this option (but that does not seem a real limitation).
4144 .vitem &%-q%&
4145 .oindex "&%-q%&"
4146 .cindex "queue runner" "starting manually"
4147 This option is normally restricted to admin users. However, there is a
4148 configuration option called &%prod_requires_admin%& which can be set false to
4149 relax this restriction (and also the same requirement for the &%-M%&, &%-R%&,
4150 and &%-S%& options).
4152 .cindex "queue runner" "description of operation"
4153 The &%-q%& option starts one queue runner process. This scans the queue of
4154 waiting messages, and runs a delivery process for each one in turn. It waits
4155 for each delivery process to finish before starting the next one. A delivery
4156 process may not actually do any deliveries if the retry times for the addresses
4157 have not been reached. Use &%-qf%& (see below) if you want to override this.
4159 If
4160 .cindex "SMTP" "passed connection"
4161 .cindex "SMTP" "multiple deliveries"
4162 .cindex "multiple SMTP deliveries"
4163 the delivery process spawns other processes to deliver other messages down
4164 passed SMTP connections, the queue runner waits for these to finish before
4165 proceeding.
4167 When all the queued messages have been considered, the original queue runner
4168 process terminates. In other words, a single pass is made over the waiting
4169 mail, one message at a time. Use &%-q%& with a time (see below) if you want
4170 this to be repeated periodically.
4172 Exim processes the waiting messages in an unpredictable order. It isn't very
4173 random, but it is likely to be different each time, which is all that matters.
4174 If one particular message screws up a remote MTA, other messages to the same
4175 MTA have a chance of getting through if they get tried first.
4177 It is possible to cause the messages to be processed in lexical message id
4178 order, which is essentially the order in which they arrived, by setting the
4179 &%queue_run_in_order%& option, but this is not recommended for normal use.
4181 .vitem &%-q%&<&'qflags'&>
4182 The &%-q%& option may be followed by one or more flag letters that change its
4183 behaviour. They are all optional, but if more than one is present, they must
4184 appear in the correct order. Each flag is described in a separate item below.
4186 .vitem &%-qq...%&
4187 .oindex "&%-qq%&"
4188 .cindex "queue" "double scanning"
4189 .cindex "queue" "routing"
4190 .cindex "routing" "whole queue before delivery"
4191 An option starting with &%-qq%& requests a two-stage queue run. In the first
4192 stage, the queue is scanned as if the &%queue_smtp_domains%& option matched
4193 every domain. Addresses are routed, local deliveries happen, but no remote
4194 transports are run.
4196 .cindex "hints database" "remembering routing"
4197 The hints database that remembers which messages are waiting for specific hosts
4198 is updated, as if delivery to those hosts had been deferred. After this is
4199 complete, a second, normal queue scan happens, with routing and delivery taking
4200 place as normal. Messages that are routed to the same host should mostly be
4201 delivered down a single SMTP
4202 .cindex "SMTP" "passed connection"
4203 .cindex "SMTP" "multiple deliveries"
4204 .cindex "multiple SMTP deliveries"
4205 connection because of the hints that were set up during the first queue scan.
4206 This option may be useful for hosts that are connected to the Internet
4207 intermittently.
4209 .vitem &%-q[q]i...%&
4210 .oindex "&%-qi%&"
4211 .cindex "queue" "initial delivery"
4212 If the &'i'& flag is present, the queue runner runs delivery processes only for
4213 those messages that haven't previously been tried. (&'i'& stands for &"initial
4214 delivery"&.) This can be helpful if you are putting messages on the queue using
4215 &%-odq%& and want a queue runner just to process the new messages.
4217 .vitem &%-q[q][i]f...%&
4218 .oindex "&%-qf%&"
4219 .cindex "queue" "forcing delivery"
4220 .cindex "delivery" "forcing in queue run"
4221 If one &'f'& flag is present, a delivery attempt is forced for each non-frozen
4222 message, whereas without &'f'& only those non-frozen addresses that have passed
4223 their retry times are tried.
4225 .vitem &%-q[q][i]ff...%&
4226 .oindex "&%-qff%&"
4227 .cindex "frozen messages" "forcing delivery"
4228 If &'ff'& is present, a delivery attempt is forced for every message, whether
4229 frozen or not.
4231 .vitem &%-q[q][i][f[f]]l%&
4232 .oindex "&%-ql%&"
4233 .cindex "queue" "local deliveries only"
4234 The &'l'& (the letter &"ell"&) flag specifies that only local deliveries are to
4235 be done. If a message requires any remote deliveries, it remains on the queue
4236 for later delivery.
4238 .vitem &%-q%&<&'qflags'&>&~<&'start&~id'&>&~<&'end&~id'&>
4239 .cindex "queue" "delivering specific messages"
4240 When scanning the queue, Exim can be made to skip over messages whose ids are
4241 lexically less than a given value by following the &%-q%& option with a
4242 starting message id. For example:
4243 .code
4244 exim -q 0t5C6f-0000c8-00
4245 .endd
4246 Messages that arrived earlier than &`0t5C6f-0000c8-00`& are not inspected. If a
4247 second message id is given, messages whose ids are lexically greater than it
4248 are also skipped. If the same id is given twice, for example,
4249 .code
4250 exim -q 0t5C6f-0000c8-00 0t5C6f-0000c8-00
4251 .endd
4252 just one delivery process is started, for that message. This differs from
4253 &%-M%& in that retry data is respected, and it also differs from &%-Mc%& in
4254 that it counts as a delivery from a queue run. Note that the selection
4255 mechanism does not affect the order in which the messages are scanned. There
4256 are also other ways of selecting specific sets of messages for delivery in a
4257 queue run &-- see &%-R%& and &%-S%&.
4259 .vitem &%-q%&<&'qflags'&><&'time'&>
4260 .cindex "queue runner" "starting periodically"
4261 .cindex "periodic queue running"
4262 When a time value is present, the &%-q%& option causes Exim to run as a daemon,
4263 starting a queue runner process at intervals specified by the given time value
4264 (whose format is described in section &<<SECTtimeformat>>&). This form of the
4265 &%-q%& option is commonly combined with the &%-bd%& option, in which case a
4266 single daemon process handles both functions. A common way of starting up a
4267 combined daemon at system boot time is to use a command such as
4268 .code
4269 /usr/exim/bin/exim -bd -q30m
4270 .endd
4271 Such a daemon listens for incoming SMTP calls, and also starts a queue runner
4272 process every 30 minutes.
4274 When a daemon is started by &%-q%& with a time value, but without &%-bd%&, no
4275 pid file is written unless one is explicitly requested by the &%-oP%& option.
4277 .vitem &%-qR%&<&'rsflags'&>&~<&'string'&>
4278 .oindex "&%-qR%&"
4279 This option is synonymous with &%-R%&. It is provided for Sendmail
4280 compatibility.
4282 .vitem &%-qS%&<&'rsflags'&>&~<&'string'&>
4283 .oindex "&%-qS%&"
4284 This option is synonymous with &%-S%&.
4286 .vitem &%-R%&<&'rsflags'&>&~<&'string'&>
4287 .oindex "&%-R%&"
4288 .cindex "queue runner" "for specific recipients"
4289 .cindex "delivery" "to given domain"
4290 .cindex "domain" "delivery to"
4291 The <&'rsflags'&> may be empty, in which case the white space before the string
4292 is optional, unless the string is &'f'&, &'ff'&, &'r'&, &'rf'&, or &'rff'&,
4293 which are the possible values for <&'rsflags'&>. White space is required if
4294 <&'rsflags'&> is not empty.
4296 This option is similar to &%-q%& with no time value, that is, it causes Exim to
4297 perform a single queue run, except that, when scanning the messages on the
4298 queue, Exim processes only those that have at least one undelivered recipient
4299 address containing the given string, which is checked in a case-independent
4300 way. If the <&'rsflags'&> start with &'r'&, <&'string'&> is interpreted as a
4301 regular expression; otherwise it is a literal string.
4303 If you want to do periodic queue runs for messages with specific recipients,
4304 you can combine &%-R%& with &%-q%& and a time value. For example:
4305 .code
4306 exim -q25m -R @special.domain.example
4307 .endd
4308 This example does a queue run for messages with recipients in the given domain
4309 every 25 minutes. Any additional flags that are specified with &%-q%& are
4310 applied to each queue run.
4312 Once a message is selected for delivery by this mechanism, all its addresses
4313 are processed. For the first selected message, Exim overrides any retry
4314 information and forces a delivery attempt for each undelivered address. This
4315 means that if delivery of any address in the first message is successful, any
4316 existing retry information is deleted, and so delivery attempts for that
4317 address in subsequently selected messages (which are processed without forcing)
4318 will run. However, if delivery of any address does not succeed, the retry
4319 information is updated, and in subsequently selected messages, the failing
4320 address will be skipped.
4322 .cindex "frozen messages" "forcing delivery"
4323 If the <&'rsflags'&> contain &'f'& or &'ff'&, the delivery forcing applies to
4324 all selected messages, not just the first; frozen messages are included when
4325 &'ff'& is present.
4327 The &%-R%& option makes it straightforward to initiate delivery of all messages
4328 to a given domain after a host has been down for some time. When the SMTP
4329 command ETRN is accepted by its ACL (see chapter &<<CHAPACL>>&), its default
4330 effect is to run Exim with the &%-R%& option, but it can be configured to run
4331 an arbitrary command instead.
4333 .vitem &%-r%&
4334 .oindex "&%-r%&"
4335 This is a documented (for Sendmail) obsolete alternative name for &%-f%&.
4337 .vitem &%-S%&<&'rsflags'&>&~<&'string'&>
4338 .oindex "&%-S%&"
4339 .cindex "delivery" "from given sender"
4340 .cindex "queue runner" "for specific senders"
4341 This option acts like &%-R%& except that it checks the string against each
4342 message's sender instead of against the recipients. If &%-R%& is also set, both
4343 conditions must be met for a message to be selected. If either of the options
4344 has &'f'& or &'ff'& in its flags, the associated action is taken.
4346 .vitem &%-Tqt%&&~<&'times'&>
4347 .oindex "&%-Tqt%&"
4348 This an option that is exclusively for use by the Exim testing suite. It is not
4349 recognized when Exim is run normally. It allows for the setting up of explicit
4350 &"queue times"& so that various warning/retry features can be tested.
4352 .vitem &%-t%&
4353 .oindex "&%-t%&"
4354 .cindex "recipient" "extracting from header lines"
4355 .cindex "&'Bcc:'& header line"
4356 .cindex "&'Cc:'& header line"
4357 .cindex "&'To:'& header line"
4358 When Exim is receiving a locally-generated, non-SMTP message on its standard
4359 input, the &%-t%& option causes the recipients of the message to be obtained
4360 from the &'To:'&, &'Cc:'&, and &'Bcc:'& header lines in the message instead of
4361 from the command arguments. The addresses are extracted before any rewriting
4362 takes place and the &'Bcc:'& header line, if present, is then removed.
4364 .cindex "Sendmail compatibility" "&%-t%& option"
4365 If the command has any arguments, they specify addresses to which the message
4366 is &'not'& to be delivered. That is, the argument addresses are removed from
4367 the recipients list obtained from the headers. This is compatible with Smail 3
4368 and in accordance with the documented behaviour of several versions of
4369 Sendmail, as described in man pages on a number of operating systems (e.g.
4370 Solaris 8, IRIX 6.5, HP-UX 11). However, some versions of Sendmail &'add'&
4371 argument addresses to those obtained from the headers, and the O'Reilly
4372 Sendmail book documents it that way. Exim can be made to add argument addresses
4373 instead of subtracting them by setting the option
4374 &%extract_addresses_remove_arguments%& false.
4376 .cindex "&%Resent-%& header lines" "with &%-t%&"
4377 If there are any &%Resent-%& header lines in the message, Exim extracts
4378 recipients from all &'Resent-To:'&, &'Resent-Cc:'&, and &'Resent-Bcc:'& header
4379 lines instead of from &'To:'&, &'Cc:'&, and &'Bcc:'&. This is for compatibility
4380 with Sendmail and other MTAs. (Prior to release 4.20, Exim gave an error if
4381 &%-t%& was used in conjunction with &%Resent-%& header lines.)
4383 RFC 2822 talks about different sets of &%Resent-%& header lines (for when a
4384 message is resent several times). The RFC also specifies that they should be
4385 added at the front of the message, and separated by &'Received:'& lines. It is
4386 not at all clear how &%-t%& should operate in the present of multiple sets,
4387 nor indeed exactly what constitutes a &"set"&.
4388 In practice, it seems that MUAs do not follow the RFC. The &%Resent-%& lines
4389 are often added at the end of the header, and if a message is resent more than
4390 once, it is common for the original set of &%Resent-%& headers to be renamed as
4391 &%X-Resent-%& when a new set is added. This removes any possible ambiguity.
4393 .vitem &%-ti%&
4394 .oindex "&%-ti%&"
4395 This option is exactly equivalent to &%-t%& &%-i%&. It is provided for
4396 compatibility with Sendmail.
4398 .vitem &%-tls-on-connect%&
4399 .oindex "&%-tls-on-connect%&"
4400 .cindex "TLS" "use without STARTTLS"
4401 .cindex "TLS" "automatic start"
4402 This option is available when Exim is compiled with TLS support. It forces all
4403 incoming SMTP connections to behave as if the incoming port is listed in the
4404 &%tls_on_connect_ports%& option. See section &<<SECTsupobssmt>>& and chapter
4405 &<<CHAPTLS>>& for further details.
4408 .vitem &%-U%&
4409 .oindex "&%-U%&"
4410 .cindex "Sendmail compatibility" "&%-U%& option ignored"
4411 Sendmail uses this option for &"initial message submission"&, and its
4412 documentation states that in future releases, it may complain about
4413 syntactically invalid messages rather than fixing them when this flag is not
4414 set. Exim ignores this option.
4416 .vitem &%-v%&
4417 .oindex "&%-v%&"
4418 This option causes Exim to write information to the standard error stream,
4419 describing what it is doing. In particular, it shows the log lines for
4420 receiving and delivering a message, and if an SMTP connection is made, the SMTP
4421 dialogue is shown. Some of the log lines shown may not actually be written to
4422 the log if the setting of &%log_selector%& discards them. Any relevant
4423 selectors are shown with each log line. If none are shown, the logging is
4424 unconditional.
4426 .vitem &%-x%&
4427 .oindex "&%-x%&"
4428 AIX uses &%-x%& for a private purpose (&"mail from a local mail program has
4429 National Language Support extended characters in the body of the mail item"&).
4430 It sets &%-x%& when calling the MTA from its &%mail%& command. Exim ignores
4431 this option.
4432 .endlist
4434 .ecindex IIDclo1
4435 .ecindex IIDclo2
4438 . ////////////////////////////////////////////////////////////////////////////
4439 . Insert a stylized DocBook comment here, to identify the end of the command
4440 . line options. This is for the benefit of the Perl script that automatically
4441 . creates a man page for the options.
4442 . ////////////////////////////////////////////////////////////////////////////
4444 .literal xml
4445 <!-- === End of command line options === -->
4446 .literal off
4452 . ////////////////////////////////////////////////////////////////////////////
4453 . ////////////////////////////////////////////////////////////////////////////
4456 .chapter "The Exim run time configuration file" "CHAPconf" &&&
4457 "The runtime configuration file"
4459 .cindex "run time configuration"
4460 .cindex "configuration file" "general description"
4461 .cindex "CONFIGURE_FILE"
4462 .cindex "configuration file" "errors in"
4463 .cindex "error" "in configuration file"
4464 .cindex "return code" "for bad configuration"
4465 Exim uses a single run time configuration file that is read whenever an Exim
4466 binary is executed. Note that in normal operation, this happens frequently,
4467 because Exim is designed to operate in a distributed manner, without central
4468 control.
4470 If a syntax error is detected while reading the configuration file, Exim
4471 writes a message on the standard error, and exits with a non-zero return code.
4472 The message is also written to the panic log. &*Note*&: Only simple syntax
4473 errors can be detected at this time. The values of any expanded options are
4474 not checked until the expansion happens, even when the expansion does not
4475 actually alter the string.
4477 The name of the configuration file is compiled into the binary for security
4478 reasons, and is specified by the CONFIGURE_FILE compilation option. In
4479 most configurations, this specifies a single file. However, it is permitted to
4480 give a colon-separated list of file names, in which case Exim uses the first
4481 existing file in the list.
4483 .cindex "EXIM_USER"
4484 .cindex "EXIM_GROUP"
4485 .cindex "CONFIGURE_OWNER"
4486 .cindex "CONFIGURE_GROUP"
4487 .cindex "configuration file" "ownership"
4488 .cindex "ownership" "configuration file"
4489 The run time configuration file must be owned by root or by the user that is
4490 specified at compile time by the EXIM_USER option, or by the user that is
4491 specified at compile time by the CONFIGURE_OWNER option (if set). The
4492 configuration file must not be world-writeable or group-writeable, unless its
4493 group is the one specified at compile time by the EXIM_GROUP option or by the
4494 CONFIGURE_GROUP option.
4496 &*Warning*&: In a conventional configuration, where the Exim binary is setuid
4497 to root, anybody who is able to edit the run time configuration file has an
4498 easy way to run commands as root. If you make your mail administrators members
4499 of the Exim group, but do not trust them with root, make sure that the run time
4500 configuration is not group writeable.
4502 A default configuration file, which will work correctly in simple situations,
4503 is provided in the file &_src/configure.default_&. If CONFIGURE_FILE
4504 defines just one file name, the installation process copies the default
4505 configuration to a new file of that name if it did not previously exist. If
4506 CONFIGURE_FILE is a list, no default is automatically installed. Chapter
4507 &<<CHAPdefconfil>>& is a &"walk-through"& discussion of the default
4508 configuration.
4512 .section "Using a different configuration file" "SECID40"
4513 .cindex "configuration file" "alternate"
4514 A one-off alternate configuration can be specified by the &%-C%& command line
4515 option, which may specify a single file or a list of files. However, when
4516 &%-C%& is used, Exim gives up its root privilege, unless called by root or the
4517 Exim user (or unless the argument for &%-C%& is identical to the built-in value
4518 from CONFIGURE_FILE). &%-C%& is useful mainly for checking the syntax of
4519 configuration files before installing them. No owner or group checks are done
4520 on a configuration file specified by &%-C%&.
4522 The privileged use of &%-C%& by the Exim user can be locked out by setting
4523 ALT_CONFIG_ROOT_ONLY in &_Local/Makefile_& when building Exim. However,
4524 if you do this, you also lock out the possibility of testing a
4525 configuration using &%-C%& right through message reception and delivery, even
4526 if the caller is root. The reception works, but by that time, Exim is running
4527 as the Exim user, so when it re-execs to regain privilege for the delivery, the
4528 use of &%-C%& causes privilege to be lost. However, root can test reception and
4529 delivery using two separate commands (one to put a message on the queue, using
4530 &%-odq%&, and another to do the delivery, using &%-M%&).
4532 If ALT_CONFIG_PREFIX is defined &_in Local/Makefile_&, it specifies a
4533 prefix string with which any file named in a &%-C%& command line option must
4534 start. In addition, the file name must not contain the sequence &"&`/../`&"&.
4535 There is no default setting for ALT_CONFIG_PREFIX; when it is unset, any file
4536 name can be used with &%-C%&.
4538 One-off changes to a configuration can be specified by the &%-D%& command line
4539 option, which defines and overrides values for macros used inside the
4540 configuration file. However, like &%-C%&, the use of this option by a
4541 non-privileged user causes Exim to discard its root privilege.
4542 If DISABLE_D_OPTION is defined in &_Local/Makefile_&, the use of &%-D%& is
4543 completely disabled, and its use causes an immediate error exit.
4545 Some sites may wish to use the same Exim binary on different machines that
4546 share a file system, but to use different configuration files on each machine.
4547 If CONFIGURE_FILE_USE_NODE is defined in &_Local/Makefile_&, Exim first
4548 looks for a file whose name is the configuration file name followed by a dot
4549 and the machine's node name, as obtained from the &[uname()]& function. If this
4550 file does not exist, the standard name is tried. This processing occurs for
4551 each file name in the list given by CONFIGURE_FILE or &%-C%&.
4553 In some esoteric situations different versions of Exim may be run under
4554 different effective uids and the CONFIGURE_FILE_USE_EUID is defined to
4555 help with this. See the comments in &_src/EDITME_& for details.
4559 .section "Configuration file format" "SECTconffilfor"
4560 .cindex "configuration file" "format of"
4561 .cindex "format" "configuration file"
4562 Exim's configuration file is divided into a number of different parts. General
4563 option settings must always appear at the start of the file. The other parts
4564 are all optional, and may appear in any order. Each part other than the first
4565 is introduced by the word &"begin"& followed by the name of the part. The
4566 optional parts are:
4568 .ilist
4569 &'ACL'&: Access control lists for controlling incoming SMTP mail (see chapter
4570 &<<CHAPACL>>&).
4571 .next
4572 .cindex "AUTH" "configuration"
4573 &'authenticators'&: Configuration settings for the authenticator drivers. These
4574 are concerned with the SMTP AUTH command (see chapter &<<CHAPSMTPAUTH>>&).
4575 .next
4576 &'routers'&: Configuration settings for the router drivers. Routers process
4577 addresses and determine how the message is to be delivered (see chapters
4578 &<<CHAProutergeneric>>&&--&<<CHAPredirect>>&).
4579 .next
4580 &'transports'&: Configuration settings for the transport drivers. Transports
4581 define mechanisms for copying messages to destinations (see chapters
4582 &<<CHAPtransportgeneric>>&&--&<<CHAPsmtptrans>>&).
4583 .next
4584 &'retry'&: Retry rules, for use when a message cannot be delivered immediately.
4585 If there is no retry section, or if it is empty (that is, no retry rules are
4586 defined), Exim will not retry deliveries. In this situation, temporary errors
4587 are treated the same as permanent errors. Retry rules are discussed in chapter
4588 &<<CHAPretry>>&.
4589 .next
4590 &'rewrite'&: Global address rewriting rules, for use when a message arrives and
4591 when new addresses are generated during delivery. Rewriting is discussed in
4592 chapter &<<CHAPrewrite>>&.
4593 .next
4594 &'local_scan'&: Private options for the &[local_scan()]& function. If you
4595 want to use this feature, you must set
4596 .code
4598 .endd
4599 in &_Local/Makefile_& before building Exim. Details of the &[local_scan()]&
4600 facility are given in chapter &<<CHAPlocalscan>>&.
4601 .endlist
4603 .cindex "configuration file" "leading white space in"
4604 .cindex "configuration file" "trailing white space in"
4605 .cindex "white space" "in configuration file"
4606 Leading and trailing white space in configuration lines is always ignored.
4608 Blank lines in the file, and lines starting with a # character (ignoring
4609 leading white space) are treated as comments and are ignored. &*Note*&: A
4610 # character other than at the beginning of a line is not treated specially,
4611 and does not introduce a comment.
4613 Any non-comment line can be continued by ending it with a backslash. Note that
4614 the general rule for white space means that trailing white space after the
4615 backslash and leading white space at the start of continuation
4616 lines is ignored. Comment lines beginning with # (but not empty lines) may
4617 appear in the middle of a sequence of continuation lines.
4619 A convenient way to create a configuration file is to start from the
4620 default, which is supplied in &_src/configure.default_&, and add, delete, or
4621 change settings as required.
4623 The ACLs, retry rules, and rewriting rules have their own syntax which is
4624 described in chapters &<<CHAPACL>>&, &<<CHAPretry>>&, and &<<CHAPrewrite>>&,
4625 respectively. The other parts of the configuration file have some syntactic
4626 items in common, and these are described below, from section &<<SECTcos>>&
4627 onwards. Before that, the inclusion, macro, and conditional facilities are
4628 described.
4632 .section "File inclusions in the configuration file" "SECID41"
4633 .cindex "inclusions in configuration file"
4634 .cindex "configuration file" "including other files"
4635 .cindex "&`.include`& in configuration file"
4636 .cindex "&`.include_if_exists`& in configuration file"
4637 You can include other files inside Exim's run time configuration file by
4638 using this syntax:
4639 .display
4640 &`.include`& <&'file name'&>
4641 &`.include_if_exists`& <&'file name'&>
4642 .endd
4643 on a line by itself. Double quotes round the file name are optional. If you use
4644 the first form, a configuration error occurs if the file does not exist; the
4645 second form does nothing for non-existent files. In all cases, an absolute file
4646 name is required.
4648 Includes may be nested to any depth, but remember that Exim reads its
4649 configuration file often, so it is a good idea to keep them to a minimum.
4650 If you change the contents of an included file, you must HUP the daemon,
4651 because an included file is read only when the configuration itself is read.
4653 The processing of inclusions happens early, at a physical line level, so, like
4654 comment lines, an inclusion can be used in the middle of an option setting,
4655 for example:
4656 .code
4657 hosts_lookup = a.b.c \
4658 .include /some/file
4659 .endd
4660 Include processing happens after macro processing (see below). Its effect is to
4661 process the lines of the included file as if they occurred inline where the
4662 inclusion appears.
4666 .section "Macros in the configuration file" "SECTmacrodefs"
4667 .cindex "macro" "description of"
4668 .cindex "configuration file" "macros"
4669 If a line in the main part of the configuration (that is, before the first
4670 &"begin"& line) begins with an upper case letter, it is taken as a macro
4671 definition, and must be of the form
4672 .display
4673 <&'name'&> = <&'rest of line'&>
4674 .endd
4675 The name must consist of letters, digits, and underscores, and need not all be
4676 in upper case, though that is recommended. The rest of the line, including any
4677 continuations, is the replacement text, and has leading and trailing white
4678 space removed. Quotes are not removed. The replacement text can never end with
4679 a backslash character, but this doesn't seem to be a serious limitation.
4681 Macros may also be defined between router, transport, authenticator, or ACL
4682 definitions. They may not, however, be defined within an individual driver or
4683 ACL, or in the &%local_scan%&, retry, or rewrite sections of the configuration.
4685 .section "Macro substitution" "SECID42"
4686 Once a macro is defined, all subsequent lines in the file (and any included
4687 files) are scanned for the macro name; if there are several macros, the line is
4688 scanned for each in turn, in the order in which the macros are defined. The
4689 replacement text is not re-scanned for the current macro, though it is scanned
4690 for subsequently defined macros. For this reason, a macro name may not contain
4691 the name of a previously defined macro as a substring. You could, for example,
4692 define
4693 .display
4694 &`ABCD_XYZ = `&<&'something'&>
4695 &`ABCD = `&<&'something else'&>
4696 .endd
4697 but putting the definitions in the opposite order would provoke a configuration
4698 error. Macro expansion is applied to individual physical lines from the file,
4699 before checking for line continuation or file inclusion (see above). If a line
4700 consists solely of a macro name, and the expansion of the macro is empty, the
4701 line is ignored. A macro at the start of a line may turn the line into a
4702 comment line or a &`.include`& line.
4705 .section "Redefining macros" "SECID43"
4706 Once defined, the value of a macro can be redefined later in the configuration
4707 (or in an included file). Redefinition is specified by using &'=='& instead of
4708 &'='&. For example:
4709 .code
4710 MAC = initial value
4711 ...
4712 MAC == updated value
4713 .endd
4714 Redefinition does not alter the order in which the macros are applied to the
4715 subsequent lines of the configuration file. It is still the same order in which
4716 the macros were originally defined. All that changes is the macro's value.
4717 Redefinition makes it possible to accumulate values. For example:
4718 .code
4719 MAC = initial value
4720 ...
4721 MAC == MAC and something added
4722 .endd
4723 This can be helpful in situations where the configuration file is built
4724 from a number of other files.
4726 .section "Overriding macro values" "SECID44"
4727 The values set for macros in the configuration file can be overridden by the
4728 &%-D%& command line option, but Exim gives up its root privilege when &%-D%& is
4729 used, unless called by root or the Exim user. A definition on the command line
4730 using the &%-D%& option causes all definitions and redefinitions within the
4731 file to be ignored.
4735 .section "Example of macro usage" "SECID45"
4736 As an example of macro usage, consider a configuration where aliases are looked
4737 up in a MySQL database. It helps to keep the file less cluttered if long
4738 strings such as SQL statements are defined separately as macros, for example:
4739 .code
4740 ALIAS_QUERY = select mailbox from user where \
4741 login='${quote_mysql:$local_part}';
4742 .endd
4743 This can then be used in a &(redirect)& router setting like this:
4744 .code
4745 data = ${lookup mysql{ALIAS_QUERY}}
4746 .endd
4747 In earlier versions of Exim macros were sometimes used for domain, host, or
4748 address lists. In Exim 4 these are handled better by named lists &-- see
4749 section &<<SECTnamedlists>>&.
4752 .section "Conditional skips in the configuration file" "SECID46"
4753 .cindex "configuration file" "conditional skips"
4754 .cindex "&`.ifdef`&"
4755 You can use the directives &`.ifdef`&, &`.ifndef`&, &`.elifdef`&,
4756 &`.elifndef`&, &`.else`&, and &`.endif`& to dynamically include or exclude
4757 portions of the configuration file. The processing happens whenever the file is
4758 read (that is, when an Exim binary starts to run).
4760 The implementation is very simple. Instances of the first four directives must
4761 be followed by text that includes the names of one or macros. The condition
4762 that is tested is whether or not any macro substitution has taken place in the
4763 line. Thus:
4764 .code
4765 .ifdef AAA
4766 message_size_limit = 50M
4767 .else
4768 message_size_limit = 100M
4769 .endif
4770 .endd
4771 sets a message size limit of 50M if the macro &`AAA`& is defined, and 100M
4772 otherwise. If there is more than one macro named on the line, the condition
4773 is true if any of them are defined. That is, it is an &"or"& condition. To
4774 obtain an &"and"& condition, you need to use nested &`.ifdef`&s.
4776 Although you can use a macro expansion to generate one of these directives,
4777 it is not very useful, because the condition &"there was a macro substitution
4778 in this line"& will always be true.
4780 Text following &`.else`& and &`.endif`& is ignored, and can be used as comment
4781 to clarify complicated nestings.
4785 .section "Common option syntax" "SECTcos"
4786 .cindex "common option syntax"
4787 .cindex "syntax of common options"
4788 .cindex "configuration file" "common option syntax"
4789 For the main set of options, driver options, and &[local_scan()]& options,
4790 each setting is on a line by itself, and starts with a name consisting of
4791 lower-case letters and underscores. Many options require a data value, and in
4792 these cases the name must be followed by an equals sign (with optional white
4793 space) and then the value. For example:
4794 .code
4795 qualify_domain = mydomain.example.com
4796 .endd
4797 .cindex "hiding configuration option values"
4798 .cindex "configuration options" "hiding value of"
4799 .cindex "options" "hiding value of"
4800 Some option settings may contain sensitive data, for example, passwords for
4801 accessing databases. To stop non-admin users from using the &%-bP%& command
4802 line option to read these values, you can precede the option settings with the
4803 word &"hide"&. For example: