[exim.git] / doc / doc-docbook / spec.xfpt
1 . $Cambridge: exim/doc/doc-docbook/spec.xfpt,v 1.27 2007/12/01 15:53:55 nm4 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 "4.68"
51 .set version "4.69"
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>23 August 2007</date>
176 <author><firstname>Philip</firstname><surname>Hazel</surname></author>
177 <authorinitials>PH</authorinitials>
178 <affiliation><orgname>University of Cambridge Computing Service</orgname></affiliation>
179 <address>New Museums Site, Pembroke Street, Cambridge CB2 3QH, England</address>
180 <revhistory><revision>
181 <revnumber>4.68</revnumber>
182 <date>23 August 2007</date>
183 <authorinitials>PH</authorinitials>
184 </revision></revhistory>
185 <copyright><year>2007</year><holder>University of Cambridge</holder></copyright>
186 </bookinfo>
187 .literal off
190 . /////////////////////////////////////////////////////////////////////////////
191 . This chunk of literal XML implements index entries of the form "x, see y" and
192 . "x, see also y". However, the DocBook DTD doesn't allow <indexterm> entries
193 . at the top level, so we have to put the .chapter directive first.
194 . /////////////////////////////////////////////////////////////////////////////
196 .chapter "Introduction" "CHID1"
197 .literal xml
199 <indexterm role="variable">
200 <primary>$1, $2, etc.</primary>
201 <see><emphasis>numerical variables</emphasis></see>
202 </indexterm>
203 <indexterm role="concept">
204 <primary>address</primary>
205 <secondary>rewriting</secondary>
206 <see><emphasis>rewriting</emphasis></see>
207 </indexterm>
208 <indexterm role="concept">
209 <primary>Bounce Address Tag Validation</primary>
210 <see><emphasis>BATV</emphasis></see>
211 </indexterm>
212 <indexterm role="concept">
213 <primary>Client SMTP Authorization</primary>
214 <see><emphasis>CSA</emphasis></see>
215 </indexterm>
216 <indexterm role="concept">
217 <primary>CR character</primary>
218 <see><emphasis>carriage return</emphasis></see>
219 </indexterm>
220 <indexterm role="concept">
221 <primary>CRL</primary>
222 <see><emphasis>certificate revocation list</emphasis></see>
223 </indexterm>
224 <indexterm role="concept">
225 <primary>delivery</primary>
226 <secondary>failure report</secondary>
227 <see><emphasis>bounce message</emphasis></see>
228 </indexterm>
229 <indexterm role="concept">
230 <primary>dialup</primary>
231 <see><emphasis>intermittently connected hosts</emphasis></see>
232 </indexterm>
233 <indexterm role="concept">
234 <primary>exiscan</primary>
235 <see><emphasis>content scanning</emphasis></see>
236 </indexterm>
237 <indexterm role="concept">
238 <primary>failover</primary>
239 <see><emphasis>fallback</emphasis></see>
240 </indexterm>
241 <indexterm role="concept">
242 <primary>fallover</primary>
243 <see><emphasis>fallback</emphasis></see>
244 </indexterm>
245 <indexterm role="concept">
246 <primary>filter</primary>
247 <secondary>Sieve</secondary>
248 <see><emphasis>Sieve filter</emphasis></see>
249 </indexterm>
250 <indexterm role="concept">
251 <primary>ident</primary>
252 <see><emphasis>RFC 1413</emphasis></see>
253 </indexterm>
254 <indexterm role="concept">
255 <primary>LF character</primary>
256 <see><emphasis>linefeed</emphasis></see>
257 </indexterm>
258 <indexterm role="concept">
259 <primary>maximum</primary>
260 <seealso><emphasis>limit</emphasis></seealso>
261 </indexterm>
262 <indexterm role="concept">
263 <primary>monitor</primary>
264 <see><emphasis>Exim monitor</emphasis></see>
265 </indexterm>
266 <indexterm role="concept">
267 <primary>no_<emphasis>xxx</emphasis></primary>
268 <see>entry for xxx</see>
269 </indexterm>
270 <indexterm role="concept">
271 <primary>NUL</primary>
272 <see><emphasis>binary zero</emphasis></see>
273 </indexterm>
274 <indexterm role="concept">
275 <primary>passwd file</primary>
276 <see><emphasis>/etc/passwd</emphasis></see>
277 </indexterm>
278 <indexterm role="concept">
279 <primary>process id</primary>
280 <see><emphasis>pid</emphasis></see>
281 </indexterm>
282 <indexterm role="concept">
283 <primary>RBL</primary>
284 <see><emphasis>DNS list</emphasis></see>
285 </indexterm>
286 <indexterm role="concept">
287 <primary>redirection</primary>
288 <see><emphasis>address redirection</emphasis></see>
289 </indexterm>
290 <indexterm role="concept">
291 <primary>return path</primary>
292 <seealso><emphasis>envelope sender</emphasis></seealso>
293 </indexterm>
294 <indexterm role="concept">
295 <primary>scanning</primary>
296 <see><emphasis>content scanning</emphasis></see>
297 </indexterm>
298 <indexterm role="concept">
299 <primary>SSL</primary>
300 <see><emphasis>TLS</emphasis></see>
301 </indexterm>
302 <indexterm role="concept">
303 <primary>string</primary>
304 <secondary>expansion</secondary>
305 <see><emphasis>expansion</emphasis></see>
306 </indexterm>
307 <indexterm role="concept">
308 <primary>top bit</primary>
309 <see><emphasis>8-bit characters</emphasis></see>
310 </indexterm>
311 <indexterm role="concept">
312 <primary>variables</primary>
313 <see><emphasis>expansion, variables</emphasis></see>
314 </indexterm>
315 <indexterm role="concept">
316 <primary>zero, binary</primary>
317 <see><emphasis>binary zero</emphasis></see>
318 </indexterm>
320 .literal off
323 . /////////////////////////////////////////////////////////////////////////////
324 . This is the real start of the first chapter. See the comment above as to why
325 . we can't have the .chapter line here.
326 . chapter "Introduction"
327 . /////////////////////////////////////////////////////////////////////////////
329 Exim is a mail transfer agent (MTA) for hosts that are running Unix or
330 Unix-like operating systems. It was designed on the assumption that it would be
331 run on hosts that are permanently connected to the Internet. However, it can be
332 used on intermittently connected hosts with suitable configuration adjustments.
334 Configuration files currently exist for the following operating systems: AIX,
335 BSD/OS (aka BSDI), Darwin (Mac OS X), DGUX, Dragonfly, FreeBSD, GNU/Hurd,
336 GNU/Linux, HI-OSF (Hitachi), HI-UX, HP-UX, IRIX, MIPS RISCOS, NetBSD, OpenBSD,
337 OpenUNIX, QNX, SCO, SCO SVR4.2 (aka UNIX-SV), Solaris (aka SunOS5), SunOS4,
338 Tru64-Unix (formerly Digital UNIX, formerly DEC-OSF1), Ultrix, and Unixware.
339 Some of these operating systems are no longer current and cannot easily be
340 tested, so the configuration files may no longer work in practice.
342 There are also configuration files for compiling Exim in the Cygwin environment
343 that can be installed on systems running Windows. However, this document does
344 not contain any information about running Exim in the Cygwin environment.
346 The terms and conditions for the use and distribution of Exim are contained in
347 the file &_NOTICE_&. Exim is distributed under the terms of the GNU General
348 Public Licence, a copy of which may be found in the file &_LICENCE_&.
350 The use, supply or promotion of Exim for the purpose of sending bulk,
351 unsolicited electronic mail is incompatible with the basic aims of the program,
352 which revolve around the free provision of a service that enhances the quality
353 of personal communications. The author of Exim regards indiscriminate
354 mass-mailing as an antisocial, irresponsible abuse of the Internet.
356 Exim owes a great deal to Smail 3 and its author, Ron Karr. Without the
357 experience of running and working on the Smail 3 code, I could never have
358 contemplated starting to write a new MTA. Many of the ideas and user interfaces
359 were originally taken from Smail 3, though the actual code of Exim is entirely
360 new, and has developed far beyond the initial concept.
362 Many people, both in Cambridge and around the world, have contributed to the
363 development and the testing of Exim, and to porting it to various operating
364 systems. I am grateful to them all. The distribution now contains a file called
365 &_ACKNOWLEDGMENTS_&, in which I have started recording the names of
366 contributors.
369 .section "Exim documentation" "SECID1"
370 .new
371 .cindex "documentation"
372 This edition of the Exim specification applies to version &version; of Exim.
373 Substantive changes from the &previousversion; edition are marked in some
374 renditions of the document; this paragraph is so marked if the rendition is
375 capable of showing a change indicator.
376 .wen
378 This document is very much a reference manual; it is not a tutorial. The reader
379 is expected to have some familiarity with the SMTP mail transfer protocol and
380 with general Unix system administration. Although there are some discussions
381 and examples in places, the information is mostly organized in a way that makes
382 it easy to look up, rather than in a natural order for sequential reading.
383 Furthermore, the manual aims to cover every aspect of Exim in detail, including
384 a number of rarely-used, special-purpose features that are unlikely to be of
385 very wide interest.
387 .cindex "books about Exim"
388 An &"easier"& discussion of Exim which provides more in-depth explanatory,
389 introductory, and tutorial material can be found in a book entitled &'The Exim
390 SMTP Mail Server'& (second edition, 2007), published by UIT Cambridge
391 (&url(http://www.uit.co.uk/exim-book/)).
393 This book also contains a chapter that gives a general introduction to SMTP and
394 Internet mail. Inevitably, however, the book is unlikely to be fully up-to-date
395 with the latest release of Exim. (Note that the earlier book about Exim,
396 published by O'Reilly, covers Exim 3, and many things have changed in Exim 4.)
398 .cindex "Debian" "information sources"
399 If you are using a Debian distribution of Exim, you will find information about
400 Debian-specific features in the file
401 &_/usr/share/doc/exim4-base/README.Debian_&.
402 The command &(man update-exim.conf)& is another source of Debian-specific
403 information.
405 .cindex "&_doc/NewStuff_&"
406 .cindex "&_doc/ChangeLog_&"
407 .cindex "change log"
408 As the program develops, there may be features in newer versions that have not
409 yet made it into this document, which is updated only when the most significant
410 digit of the fractional part of the version number changes. Specifications of
411 new features that are not yet in this manual are placed in the file
412 &_doc/NewStuff_& in the Exim distribution.
414 Some features may be classified as &"experimental"&. These may change
415 incompatibly while they are developing, or even be withdrawn. For this reason,
416 they are not documented in this manual. Information about experimental features
417 can be found in the file &_doc/experimental.txt_&.
419 All changes to the program (whether new features, bug fixes, or other kinds of
420 change) are noted briefly in the file called &_doc/ChangeLog_&.
422 .cindex "&_doc/spec.txt_&"
423 This specification itself is available as an ASCII file in &_doc/spec.txt_& so
424 that it can easily be searched with a text editor. Other files in the &_doc_&
425 directory are:
427 .table2 100pt
428 .row &_OptionLists.txt_& "list of all options in alphabetical order"
429 .row &_dbm.discuss.txt_& "discussion about DBM libraries"
430 .row &_exim.8_& "a man page of Exim's command line options"
431 .row &_experimental.txt_& "documentation of experimental features"
432 .row &_filter.txt_& "specification of the filter language"
433 .row &_pcrepattern.txt_& "specification of PCRE regular expressions"
434 .row &_pcretest.txt_& "specification of the PCRE testing program"
435 .row &_Exim3.upgrade_& "upgrade notes from release 2 to release 3"
436 .row &_Exim4.upgrade_& "upgrade notes from release 3 to release 4"
437 .endtable
439 The main specification and the specification of the filtering language are also
440 available in other formats (HTML, PostScript, PDF, and Texinfo). Section
441 &<<SECTavail>>& below tells you how to get hold of these.
445 .section "FTP and web sites" "SECID2"
446 .cindex "web site"
447 .cindex "FTP site"
448 The primary site for Exim source distributions is currently the University of
449 Cambridge's FTP site, whose contents are described in &'Where to find the Exim
450 distribution'& below. In addition, there is a web site and an FTP site at
451 &%exim.org%&. These are now also hosted at the University of Cambridge. The
452 &%exim.org%& site was previously hosted for a number of years by Energis
453 Squared, formerly Planet Online Ltd, whose support I gratefully acknowledge.
455 .cindex "wiki"
456 .cindex "FAQ"
457 As well as Exim distribution tar files, the Exim web site contains a number of
458 differently formatted versions of the documentation. A recent addition to the
459 online information is the Exim wiki &new("(&url(http://wiki.exim.org))"),
460 which contains what used to be a separate FAQ, as well as various other
461 examples, tips, and know-how that have been contributed by Exim users.
463 .cindex Bugzilla
464 An Exim Bugzilla exists at &new("&url(http://bugs.exim.org)"). You can use
465 this to report bugs, and also to add items to the wish list. Please search
466 first to check that you are not duplicating a previous entry.
470 .section "Mailing lists" "SECID3"
471 .cindex "mailing lists" "for Exim users"
472 The following Exim mailing lists exist:
474 .table2 140pt
475 .row &'exim-users@exim.org'& "General discussion list"
476 .row &'exim-dev@exim.org'& "Discussion of bugs, enhancements, etc."
477 .row &'exim-announce@exim.org'& "Moderated, low volume announcements list"
478 .row &'exim-future@exim.org'& "Discussion of long-term development"
479 .endtable
481 You can subscribe to these lists, change your existing subscriptions, and view
482 or search the archives via the mailing lists link on the Exim home page.
483 .cindex "Debian" "mailing list for"
484 If you are using a Debian distribution of Exim, you may wish to subscribe to
485 the Debian-specific mailing list &'pkg-exim4-users@lists.alioth.debian.org'&
486 via this web page:
487 .display
488 &url(http://lists.alioth.debian.org/mailman/listinfo/pkg-exim4-users)
489 .endd
490 Please ask Debian-specific questions on this list and not on the general Exim
491 lists.
493 .section "Exim training" "SECID4"
494 .cindex "training courses"
495 Training courses in Cambridge (UK) used to be run annually by the author of
496 Exim, before he retired. At the time of writing, there are no plans to run
497 further Exim courses in Cambridge. However, if that changes, relevant
498 information will be posted at &url(http://www-tus.csx.cam.ac.uk/courses/exim/).
500 .section "Bug reports" "SECID5"
501 .cindex "bug reports"
502 .cindex "reporting bugs"
503 Reports of obvious bugs &new("can be emailed to &'bugs@exim.org'& or reported
504 via the Bugzilla (&url(http://bugs.exim.org)).") However, if you are unsure
505 whether some behaviour is a bug or not, the best thing to do is to post a
506 message to the &'exim-dev'& mailing list and have it discussed.
510 .section "Where to find the Exim distribution" "SECTavail"
511 .cindex "FTP site"
512 .cindex "distribution" "ftp site"
513 The master ftp site for the Exim distribution is
514 .display
515 &*ftp://ftp.csx.cam.ac.uk/pub/software/email/exim*&
516 .endd
517 This is mirrored by
518 .display
519 &*ftp://ftp.exim.org/pub/exim*&
520 .endd
521 The file references that follow are relative to the &_exim_& directories at
522 these sites. There are now quite a number of independent mirror sites around
523 the world. Those that I know about are listed in the file called &_Mirrors_&.
525 Within the &_exim_& directory there are subdirectories called &_exim3_& (for
526 previous Exim 3 distributions), &_exim4_& (for the latest Exim 4
527 distributions), and &_Testing_& for testing versions. In the &_exim4_&
528 subdirectory, the current release can always be found in files called
529 .display
530 &_exim-n.nn.tar.gz_&
531 &_exim-n.nn.tar.bz2_&
532 .endd
533 where &'n.nn'& is the highest such version number in the directory. The two
534 files contain identical data; the only difference is the type of compression.
535 The &_.bz2_& file is usually a lot smaller than the &_.gz_& file.
537 .cindex "distribution" "signing details"
538 .cindex "distribution" "public key"
539 .cindex "public key for signed distribution"
540 The distributions are currently signed with Philip Hazel's GPG key. The
541 corresponding public key is available from a number of keyservers, and there is
542 also a copy in the file &_Public-Key_&. The signatures for the tar bundles are
543 in:
544 .display
545 &_exim-n.nn.tar.gz.sig_&
546 &_exim-n.nn.tar.bz2.sig_&
547 .endd
548 For each released version, the log of changes is made separately available in a
549 separate file in the directory &_ChangeLogs_& so that it is possible to
550 find out what has changed without having to download the entire distribution.
552 .cindex "documentation" "available formats"
553 The main distribution contains ASCII versions of this specification and other
554 documentation; other formats of the documents are available in separate files
555 inside the &_exim4_& directory of the FTP site:
556 .display
557 &_exim-html-n.nn.tar.gz_&
558 &_exim-pdf-n.nn.tar.gz_&
559 &_exim-postscript-n.nn.tar.gz_&
560 &_exim-texinfo-n.nn.tar.gz_&
561 .endd
562 These tar files contain only the &_doc_& directory, not the complete
563 distribution, and are also available in &_.bz2_& as well as &_.gz_& forms.
566 .section "Limitations" "SECID6"
567 .ilist
568 .cindex "limitations of Exim"
569 .cindex "bang paths" "not handled by Exim"
570 Exim is designed for use as an Internet MTA, and therefore handles addresses in
571 RFC 2822 domain format only. It cannot handle UUCP &"bang paths"&, though
572 simple two-component bang paths can be converted by a straightforward rewriting
573 configuration. This restriction does not prevent Exim from being interfaced to
574 UUCP as a transport mechanism, provided that domain addresses are used.
575 .next
576 .cindex "domainless addresses"
577 .cindex "address" "without domain"
578 Exim insists that every address it handles has a domain attached. For incoming
579 local messages, domainless addresses are automatically qualified with a
580 configured domain value. Configuration options specify from which remote
581 systems unqualified addresses are acceptable. These are then qualified on
582 arrival.
583 .next
584 .cindex "transport" "external"
585 .cindex "external transports"
586 The only external transport mechanisms that are currently implemented are SMTP
587 and LMTP over a TCP/IP network (including support for IPv6). However, a pipe
588 transport is available, and there are facilities for writing messages to files
589 and pipes, optionally in &'batched SMTP'& format; these facilities can be used
590 to send messages to other transport mechanisms such as UUCP, provided they can
591 handle domain-style addresses. Batched SMTP input is also catered for.
592 .next
593 Exim is not designed for storing mail for dial-in hosts. When the volumes of
594 such mail are large, it is better to get the messages &"delivered"& into files
595 (that is, off Exim's queue) and subsequently passed on to the dial-in hosts by
596 other means.
597 .next
598 Although Exim does have basic facilities for scanning incoming messages, these
599 are not comprehensive enough to do full virus or spam scanning. Such operations
600 are best carried out using additional specialized software packages. If you
601 compile Exim with the content-scanning extension, straightforward interfaces to
602 a number of common scanners are provided.
603 .endlist
606 .section "Run time configuration" "SECID7"
607 Exim's run time configuration is held in a single text file that is divided
608 into a number of sections. The entries in this file consist of keywords and
609 values, in the style of Smail 3 configuration files. A default configuration
610 file which is suitable for simple online installations is provided in the
611 distribution, and is described in chapter &<<CHAPdefconfil>>& below.
614 .section "Calling interface" "SECID8"
615 .cindex "Sendmail compatibility" "command line interface"
616 Like many MTAs, Exim has adopted the Sendmail command line interface so that it
617 can be a straight replacement for &_/usr/lib/sendmail_& or
618 &_/usr/sbin/sendmail_& when sending mail, but you do not need to know anything
619 about Sendmail in order to run Exim. For actions other than sending messages,
620 Sendmail-compatible options also exist, but those that produce output (for
621 example, &%-bp%&, which lists the messages on the queue) do so in Exim's own
622 format. There are also some additional options that are compatible with Smail
623 3, and some further options that are new to Exim. Chapter &<<CHAPcommandline>>&
624 documents all Exim's command line options. This information is automatically
625 made into the man page that forms part of the Exim distribution.
627 Control of messages on the queue can be done via certain privileged command
628 line options. There is also an optional monitor program called &'eximon'&,
629 which displays current information in an X window, and which contains a menu
630 interface to Exim's command line administration options.
634 .section "Terminology" "SECID9"
635 .cindex "terminology definitions"
636 .cindex "body of message" "definition of"
637 The &'body'& of a message is the actual data that the sender wants to transmit.
638 It is the last part of a message, and is separated from the &'header'& (see
639 below) by a blank line.
641 .cindex "bounce message" "definition of"
642 When a message cannot be delivered, it is normally returned to the sender in a
643 delivery failure message or a &"non-delivery report"& (NDR). The term
644 &'bounce'& is commonly used for this action, and the error reports are often
645 called &'bounce messages'&. This is a convenient shorthand for &"delivery
646 failure error report"&. Such messages have an empty sender address in the
647 message's &'envelope'& (see below) to ensure that they cannot themselves give
648 rise to further bounce messages.
650 The term &'default'& appears frequently in this manual. It is used to qualify a
651 value which is used in the absence of any setting in the configuration. It may
652 also qualify an action which is taken unless a configuration setting specifies
653 otherwise.
655 The term &'defer'& is used when the delivery of a message to a specific
656 destination cannot immediately take place for some reason (a remote host may be
657 down, or a user's local mailbox may be full). Such deliveries are &'deferred'&
658 until a later time.
660 The word &'domain'& is sometimes used to mean all but the first component of a
661 host's name. It is &'not'& used in that sense here, where it normally refers to
662 the part of an email address following the @ sign.
664 .cindex "envelope, definition of"
665 .cindex "sender" "definition of"
666 A message in transit has an associated &'envelope'&, as well as a header and a
667 body. The envelope contains a sender address (to which bounce messages should
668 be delivered), and any number of recipient addresses. References to the
669 sender or the recipients of a message usually mean the addresses in the
670 envelope. An MTA uses these addresses for delivery, and for returning bounce
671 messages, not the addresses that appear in the header lines.
673 .cindex "message" "header, definition of"
674 .cindex "header section" "definition of"
675 The &'header'& of a message is the first part of a message's text, consisting
676 of a number of lines, each of which has a name such as &'From:'&, &'To:'&,
677 &'Subject:'&, etc. Long header lines can be split over several text lines by
678 indenting the continuations. The header is separated from the body by a blank
679 line.
681 .cindex "local part" "definition of"
682 .cindex "domain" "definition of"
683 The term &'local part'&, which is taken from RFC 2822, is used to refer to that
684 part of an email address that precedes the @ sign. The part that follows the
685 @ sign is called the &'domain'& or &'mail domain'&.
687 .cindex "local delivery" "definition of"
688 .cindex "remote delivery, definition of"
689 The terms &'local delivery'& and &'remote delivery'& are used to distinguish
690 delivery to a file or a pipe on the local host from delivery by SMTP over
691 TCP/IP to another host. As far as Exim is concerned, all hosts other than the
692 host it is running on are &'remote'&.
694 .cindex "return path" "definition of"
695 &'Return path'& is another name that is used for the sender address in a
696 message's envelope.
698 .cindex "queue" "definition of"
699 The term &'queue'& is used to refer to the set of messages awaiting delivery,
700 because this term is in widespread use in the context of MTAs. However, in
701 Exim's case the reality is more like a pool than a queue, because there is
702 normally no ordering of waiting messages.
704 .cindex "queue runner" "definition of"
705 The term &'queue runner'& is used to describe a process that scans the queue
706 and attempts to deliver those messages whose retry times have come. This term
707 is used by other MTAs, and also relates to the command &%runq%&, but in Exim
708 the waiting messages are normally processed in an unpredictable order.
710 .cindex "spool directory" "definition of"
711 The term &'spool directory'& is used for a directory in which Exim keeps the
712 messages on its queue &-- that is, those that it is in the process of
713 delivering. This should not be confused with the directory in which local
714 mailboxes are stored, which is called a &"spool directory"& by some people. In
715 the Exim documentation, &"spool"& is always used in the first sense.
722 . ////////////////////////////////////////////////////////////////////////////
723 . ////////////////////////////////////////////////////////////////////////////
725 .chapter "Incorporated code" "CHID2"
726 .cindex "incorporated code"
727 .cindex "regular expressions" "library"
728 .cindex "PCRE"
729 A number of pieces of external code are included in the Exim distribution.
731 .ilist
732 Regular expressions are supported in the main Exim program and in the Exim
733 monitor using the freely-distributable PCRE library, copyright &copy;
734 University of Cambridge. The source is distributed in the directory
735 &_src/pcre_&. However, this is a cut-down version of PCRE. If you want to use
736 the PCRE library in other programs, you should obtain and install the full
737 version of the library from
738 &url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre).
739 .next
740 .cindex "cdb" "acknowledgment"
741 Support for the cdb (Constant DataBase) lookup method is provided by code
742 contributed by Nigel Metheringham of (at the time he contributed it) Planet
743 Online Ltd. The implementation is completely contained within the code of Exim.
744 It does not link against an external cdb library. The code contains the
745 following statements:
747 .blockquote
748 Copyright &copy; 1998 Nigel Metheringham, Planet Online Ltd
750 This program is free software; you can redistribute it and/or modify it under
751 the terms of the GNU General Public License as published by the Free Software
752 Foundation; either version 2 of the License, or (at your option) any later
753 version.
754 This code implements Dan Bernstein's Constant DataBase (cdb) spec. Information,
755 the spec and sample code for cdb can be obtained from
756 &url(http://www.pobox.com/~djb/cdb.html). This implementation borrows
757 some code from Dan Bernstein's implementation (which has no license
758 restrictions applied to it).
759 .endblockquote
760 .next
761 .cindex "SPA authentication"
762 .cindex "Samba project"
763 .cindex "Microsoft Secure Password Authentication"
764 Client support for Microsoft's &'Secure Password Authentication'& is provided
765 by code contributed by Marc Prud'hommeaux. Server support was contributed by
766 Tom Kistner. This includes code taken from the Samba project, which is released
767 under the Gnu GPL.
768 .next
769 .cindex "Cyrus"
770 .cindex "&'pwcheck'& daemon"
771 .cindex "&'pwauthd'& daemon"
772 Support for calling the Cyrus &'pwcheck'& and &'saslauthd'& daemons is provided
773 by code taken from the Cyrus-SASL library and adapted by Alexander S.
774 Sabourenkov. The permission notice appears below, in accordance with the
775 conditions expressed therein.
777 .blockquote
778 Copyright &copy; 2001 Carnegie Mellon University. All rights reserved.
780 Redistribution and use in source and binary forms, with or without
781 modification, are permitted provided that the following conditions
782 are met:
784 .olist
785 Redistributions of source code must retain the above copyright
786 notice, this list of conditions and the following disclaimer.
787 .next
788 Redistributions in binary form must reproduce the above copyright
789 notice, this list of conditions and the following disclaimer in
790 the documentation and/or other materials provided with the
791 distribution.
792 .next
793 The name &"Carnegie Mellon University"& must not be used to
794 endorse or promote products derived from this software without
795 prior written permission. For permission or any other legal
796 details, please contact
797 .display
798 Office of Technology Transfer
799 Carnegie Mellon University
800 5000 Forbes Avenue
801 Pittsburgh, PA 15213-3890
802 (412) 268-4387, fax: (412) 268-7395
803 tech-transfer@andrew.cmu.edu
804 .endd
805 .next
806 Redistributions of any form whatsoever must retain the following
807 acknowledgment:
809 &"This product includes software developed by Computing Services
810 at Carnegie Mellon University (&url(http://www.cmu.edu/computing/)."&
819 .endlist
820 .endblockquote
822 .next
823 .cindex "Exim monitor" "acknowledgment"
824 .cindex "X-windows"
825 .cindex "Athena"
826 The Exim Monitor program, which is an X-Window application, includes
827 modified versions of the Athena StripChart and TextPop widgets.
828 This code is copyright by DEC and MIT, and their permission notice appears
829 below, in accordance with the conditions expressed therein.
831 .blockquote
832 Copyright 1987, 1988 by Digital Equipment Corporation, Maynard, Massachusetts,
833 and the Massachusetts Institute of Technology, Cambridge, Massachusetts.
835 All Rights Reserved
837 Permission to use, copy, modify, and distribute this software and its
838 documentation for any purpose and without fee is hereby granted,
839 provided that the above copyright notice appear in all copies and that
840 both that copyright notice and this permission notice appear in
841 supporting documentation, and that the names of Digital or MIT not be
842 used in advertising or publicity pertaining to distribution of the
843 software without specific, written prior permission.
852 .endblockquote
854 .next
855 Many people have contributed code fragments, some large, some small, that were
856 not covered by any specific licence requirements. It is assumed that the
857 contributors are happy to see their code incorporated into Exim under the GPL.
858 .endlist
864 . ////////////////////////////////////////////////////////////////////////////
865 . ////////////////////////////////////////////////////////////////////////////
867 .chapter "How Exim receives and delivers mail" "CHID11" &&&
868 "Receiving and delivering mail"
871 .section "Overall philosophy" "SECID10"
872 .cindex "design philosophy"
873 Exim is designed to work efficiently on systems that are permanently connected
874 to the Internet and are handling a general mix of mail. In such circumstances,
875 most messages can be delivered immediately. Consequently, Exim does not
876 maintain independent queues of messages for specific domains or hosts, though
877 it does try to send several messages in a single SMTP connection after a host
878 has been down, and it also maintains per-host retry information.
881 .section "Policy control" "SECID11"
882 .cindex "policy control" "overview"
883 Policy controls are now an important feature of MTAs that are connected to the
884 Internet. Perhaps their most important job is to stop MTAs being abused as
885 &"open relays"& by misguided individuals who send out vast amounts of
886 unsolicited junk, and want to disguise its source. Exim provides flexible
887 facilities for specifying policy controls on incoming mail:
889 .ilist
890 .cindex "&ACL;" "introduction"
891 Exim 4 (unlike previous versions of Exim) implements policy controls on
892 incoming mail by means of &'Access Control Lists'& (ACLs). Each list is a
893 series of statements that may either grant or deny access. ACLs can be used at
894 several places in the SMTP dialogue while receiving a message from a remote
895 host. However, the most common places are after each RCPT command, and at the
896 very end of the message. The sysadmin can specify conditions for accepting or
897 rejecting individual recipients or the entire message, respectively, at these
898 two points (see chapter &<<CHAPACL>>&). Denial of access results in an SMTP
899 error code.
900 .next
901 An ACL is also available for locally generated, non-SMTP messages. In this
902 case, the only available actions are to accept or deny the entire message.
903 .next
904 When Exim is compiled with the content-scanning extension, facilities are
905 provided in the ACL mechanism for passing the message to external virus and/or
906 spam scanning software. The result of such a scan is passed back to the ACL,
907 which can then use it to decide what to do with the message.
908 .next
909 When a message has been received, either from a remote host or from the local
910 host, but before the final acknowledgment has been sent, a locally supplied C
911 function called &[local_scan()]& can be run to inspect the message and decide
912 whether to accept it or not (see chapter &<<CHAPlocalscan>>&). If the message
913 is accepted, the list of recipients can be modified by the function.
914 .next
915 Using the &[local_scan()]& mechanism is another way of calling external scanner
916 software. The &%SA-Exim%& add-on package works this way. It does not require
917 Exim to be compiled with the content-scanning extension.
918 .next
919 After a message has been accepted, a further checking mechanism is available in
920 the form of the &'system filter'& (see chapter &<<CHAPsystemfilter>>&). This
921 runs at the start of every delivery process.
922 .endlist
926 .section "User filters" "SECID12"
927 .cindex "filter" "introduction"
928 .cindex "Sieve filter"
929 In a conventional Exim configuration, users are able to run private filters by
930 setting up appropriate &_.forward_& files in their home directories. See
931 chapter &<<CHAPredirect>>& (about the &(redirect)& router) for the
932 configuration needed to support this, and the separate document entitled
933 &'Exim's interfaces to mail filtering'& for user details. Two different kinds
934 of filtering are available:
936 .ilist
937 Sieve filters are written in the standard filtering language that is defined
938 by RFC 3028.
939 .next
940 Exim filters are written in a syntax that is unique to Exim, but which is more
941 powerful than Sieve, which it pre-dates.
942 .endlist
944 User filters are run as part of the routing process, described below.
948 .section "Message identification" "SECTmessiden"
949 .cindex "message ids" "details of format"
950 .cindex "format" "of message id"
951 .cindex "id of message"
952 .cindex "base62"
953 .cindex "base36"
954 .cindex "Darwin"
955 .cindex "Cygwin"
956 Every message handled by Exim is given a &'message id'& which is sixteen
957 characters long. It is divided into three parts, separated by hyphens, for
958 example &`16VDhn-0001bo-D3`&. Each part is a sequence of letters and digits,
959 normally encoding numbers in base 62. However, in the Darwin operating
960 system (Mac OS X) and when Exim is compiled to run under Cygwin, base 36
961 (avoiding the use of lower case letters) is used instead, because the message
962 id is used to construct file names, and the names of files in those systems are
963 not always case-sensitive.
965 .cindex "pid (process id)" "re-use of"
966 The detail of the contents of the message id have changed as Exim has evolved.
967 Earlier versions relied on the operating system not re-using a process id (pid)
968 within one second. On modern operating systems, this assumption can no longer
969 be made, so the algorithm had to be changed. To retain backward compatibility,
970 the format of the message id was retained, which is why the following rules are
971 somewhat eccentric:
973 .ilist
974 The first six characters of the message id are the time at which the message
975 started to be received, to a granularity of one second. That is, this field
976 contains the number of seconds since the start of the epoch (the normal Unix
977 way of representing the date and time of day).
978 .next
979 After the first hyphen, the next six characters are the id of the process that
980 received the message.
981 .next
982 There are two different possibilities for the final two characters:
983 .olist
984 .oindex "&%localhost_number%&"
985 If &%localhost_number%& is not set, this value is the fractional part of the
986 time of reception, normally in units of 1/2000 of a second, but for systems
987 that must use base 36 instead of base 62 (because of case-insensitive file
988 systems), the units are 1/1000 of a second.
989 .next
990 If &%localhost_number%& is set, it is multiplied by 200 (100) and added to
991 the fractional part of the time, which in this case is in units of 1/200
992 (1/100) of a second.
993 .endlist
994 .endlist
996 After a message has been received, Exim waits for the clock to tick at the
997 appropriate resolution before proceeding, so that if another message is
998 received by the same process, or by another process with the same (re-used)
999 pid, it is guaranteed that the time will be different. In most cases, the clock
1000 will already have ticked while the message was being received.
1003 .section "Receiving mail" "SECID13"
1004 .cindex "receiving mail"
1005 .cindex "message" "reception"
1006 The only way Exim can receive mail from another host is using SMTP over
1007 TCP/IP, in which case the sender and recipient addresses are transferred using
1008 SMTP commands. However, from a locally running process (such as a user's MUA),
1009 there are several possibilities:
1011 .ilist
1012 If the process runs Exim with the &%-bm%& option, the message is read
1013 non-interactively (usually via a pipe), with the recipients taken from the
1014 command line, or from the body of the message if &%-t%& is also used.
1015 .next
1016 If the process runs Exim with the &%-bS%& option, the message is also read
1017 non-interactively, but in this case the recipients are listed at the start of
1018 the message in a series of SMTP RCPT commands, terminated by a DATA
1019 command. This is so-called &"batch SMTP"& format,
1020 but it isn't really SMTP. The SMTP commands are just another way of passing
1021 envelope addresses in a non-interactive submission.
1022 .next
1023 If the process runs Exim with the &%-bs%& option, the message is read
1024 interactively, using the SMTP protocol. A two-way pipe is normally used for
1025 passing data between the local process and the Exim process.
1026 This is &"real"& SMTP and is handled in the same way as SMTP over TCP/IP. For
1027 example, the ACLs for SMTP commands are used for this form of submission.
1028 .next
1029 A local process may also make a TCP/IP call to the host's loopback address
1030 ( or any other of its IP addresses. When receiving messages, Exim
1031 does not treat the loopback address specially. It treats all such connections
1032 in the same way as connections from other hosts.
1033 .endlist
1036 .cindex "message sender, constructed by Exim"
1037 .cindex "sender" "constructed by Exim"
1038 In the three cases that do not involve TCP/IP, the sender address is
1039 constructed from the login name of the user that called Exim and a default
1040 qualification domain (which can be set by the &%qualify_domain%& configuration
1041 option). For local or batch SMTP, a sender address that is passed using the
1042 SMTP MAIL command is ignored. However, the system administrator may allow
1043 certain users (&"trusted users"&) to specify a different sender address
1044 unconditionally, or all users to specify certain forms of different sender
1045 address. The &%-f%& option or the SMTP MAIL command is used to specify these
1046 different addresses. See section &<<SECTtrustedadmin>>& for details of trusted
1047 users, and the &%untrusted_set_sender%& option for a way of allowing untrusted
1048 users to change sender addresses.
1050 Messages received by either of the non-interactive mechanisms are subject to
1051 checking by the non-SMTP ACL, if one is defined. Messages received using SMTP
1052 (either over TCP/IP, or interacting with a local process) can be checked by a
1053 number of ACLs that operate at different times during the SMTP session. Either
1054 individual recipients, or the entire message, can be rejected if local policy
1055 requirements are not met. The &[local_scan()]& function (see chapter
1056 &<<CHAPlocalscan>>&) is run for all incoming messages.
1058 Exim can be configured not to start a delivery process when a message is
1059 received; this can be unconditional, or depend on the number of incoming SMTP
1060 connections or the system load. In these situations, new messages wait on the
1061 queue until a queue runner process picks them up. However, in standard
1062 configurations under normal conditions, delivery is started as soon as a
1063 message is received.
1069 .section "Handling an incoming message" "SECID14"
1070 .cindex "spool directory" "files that hold a message"
1071 .cindex "file" "how a message is held"
1072 When Exim accepts a message, it writes two files in its spool directory. The
1073 first contains the envelope information, the current status of the message, and
1074 the header lines, and the second contains the body of the message. The names of
1075 the two spool files consist of the message id, followed by &`-H`& for the
1076 file containing the envelope and header, and &`-D`& for the data file.
1078 .cindex "spool directory" "&_input_& sub-directory"
1079 By default all these message files are held in a single directory called
1080 &_input_& inside the general Exim spool directory. Some operating systems do
1081 not perform very well if the number of files in a directory gets large; to
1082 improve performance in such cases, the &%split_spool_directory%& option can be
1083 used. This causes Exim to split up the input files into 62 sub-directories
1084 whose names are single letters or digits. When this is done, the queue is
1085 processed one sub-directory at a time instead of all at once, which can improve
1086 overall performance even when there are not enough files in each directory to
1087 affect file system performance.
1089 The envelope information consists of the address of the message's sender and
1090 the addresses of the recipients. This information is entirely separate from
1091 any addresses contained in the header lines. The status of the message includes
1092 a list of recipients who have already received the message. The format of the
1093 first spool file is described in chapter &<<CHAPspool>>&.
1095 .cindex "rewriting" "addresses"
1096 Address rewriting that is specified in the rewrite section of the configuration
1097 (see chapter &<<CHAPrewrite>>&) is done once and for all on incoming addresses,
1098 both in the header lines and the envelope, at the time the message is accepted.
1099 If during the course of delivery additional addresses are generated (for
1100 example, via aliasing), these new addresses are rewritten as soon as they are
1101 generated. At the time a message is actually delivered (transported) further
1102 rewriting can take place; because this is a transport option, it can be
1103 different for different forms of delivery. It is also possible to specify the
1104 addition or removal of certain header lines at the time the message is
1105 delivered (see chapters &<<CHAProutergeneric>>& and
1106 &<<CHAPtransportgeneric>>&).
1110 .section "Life of a message" "SECID15"
1111 .cindex "message" "life of"
1112 .cindex "message" "frozen"
1113 A message remains in the spool directory until it is completely delivered to
1114 its recipients or to an error address, or until it is deleted by an
1115 administrator or by the user who originally created it. In cases when delivery
1116 cannot proceed &-- for example, when a message can neither be delivered to its
1117 recipients nor returned to its sender, the message is marked &"frozen"& on the
1118 spool, and no more deliveries are attempted.
1120 .cindex "frozen messages" "thawing"
1121 .cindex "message" "thawing frozen"
1122 An administrator can &"thaw"& such messages when the problem has been
1123 corrected, and can also freeze individual messages by hand if necessary. In
1124 addition, an administrator can force a delivery error, causing a bounce message
1125 to be sent.
1127 .oindex "&%timeout_frozen_after%&"
1128 .oindex "&%ignore_bounce_errors_after%&"
1129 There are options called &%ignore_bounce_errors_after%& and
1130 &%timeout_frozen_after%&, which discard frozen messages after a certain time.
1131 The first applies only to frozen bounces, the second to any frozen messages.
1133 .cindex "message" "log file for"
1134 .cindex "log" "file for each message"
1135 While Exim is working on a message, it writes information about each delivery
1136 attempt to its main log file. This includes successful, unsuccessful, and
1137 delayed deliveries for each recipient (see chapter &<<CHAPlog>>&). The log
1138 lines are also written to a separate &'message log'& file for each message.
1139 These logs are solely for the benefit of the administrator, and are normally
1140 deleted along with the spool files when processing of a message is complete.
1141 The use of individual message logs can be disabled by setting
1142 &%no_message_logs%&; this might give an improvement in performance on very busy
1143 systems.
1145 .cindex "journal file"
1146 .cindex "file" "journal"
1147 All the information Exim itself needs to set up a delivery is kept in the first
1148 spool file, along with the header lines. When a successful delivery occurs, the
1149 address is immediately written at the end of a journal file, whose name is the
1150 message id followed by &`-J`&. At the end of a delivery run, if there are some
1151 addresses left to be tried again later, the first spool file (the &`-H`& file)
1152 is updated to indicate which these are, and the journal file is then deleted.
1153 Updating the spool file is done by writing a new file and renaming it, to
1154 minimize the possibility of data loss.
1156 Should the system or the program crash after a successful delivery but before
1157 the spool file has been updated, the journal is left lying around. The next
1158 time Exim attempts to deliver the message, it reads the journal file and
1159 updates the spool file before proceeding. This minimizes the chances of double
1160 deliveries caused by crashes.
1164 .section "Processing an address for delivery" "SECTprocaddress"
1165 .cindex "drivers" "definition of"
1166 .cindex "router" "definition of"
1167 .cindex "transport" "definition of"
1168 The main delivery processing elements of Exim are called &'routers'& and
1169 &'transports'&, and collectively these are known as &'drivers'&. Code for a
1170 number of them is provided in the source distribution, and compile-time options
1171 specify which ones are included in the binary. Run time options specify which
1172 ones are actually used for delivering messages.
1174 .cindex "drivers" "instance definition"
1175 Each driver that is specified in the run time configuration is an &'instance'&
1176 of that particular driver type. Multiple instances are allowed; for example,
1177 you can set up several different &(smtp)& transports, each with different
1178 option values that might specify different ports or different timeouts. Each
1179 instance has its own identifying name. In what follows we will normally use the
1180 instance name when discussing one particular instance (that is, one specific
1181 configuration of the driver), and the generic driver name when discussing
1182 the driver's features in general.
1184 A &'router'& is a driver that operates on an address, either determining how
1185 its delivery should happen, by assigning it to a specific transport, or
1186 converting the address into one or more new addresses (for example, via an
1187 alias file). A router may also explicitly choose to fail an address, causing it
1188 to be bounced.
1190 A &'transport'& is a driver that transmits a copy of the message from Exim's
1191 spool to some destination. There are two kinds of transport: for a &'local'&
1192 transport, the destination is a file or a pipe on the local host, whereas for a
1193 &'remote'& transport the destination is some other host. A message is passed
1194 to a specific transport as a result of successful routing. If a message has
1195 several recipients, it may be passed to a number of different transports.
1197 .cindex "preconditions" "definition of"
1198 An address is processed by passing it to each configured router instance in
1199 turn, subject to certain preconditions, until a router accepts the address or
1200 specifies that it should be bounced. We will describe this process in more
1201 detail shortly. First, as a simple example, we consider how each recipient
1202 address in a message is processed in a small configuration of three routers.
1204 To make this a more concrete example, it is described in terms of some actual
1205 routers, but remember, this is only an example. You can configure Exim's
1206 routers in many different ways, and there may be any number of routers in a
1207 configuration.
1209 The first router that is specified in a configuration is often one that handles
1210 addresses in domains that are not recognized specially by the local host. These
1211 are typically addresses for arbitrary domains on the Internet. A precondition
1212 is set up which looks for the special domains known to the host (for example,
1213 its own domain name), and the router is run for addresses that do &'not'&
1214 match. Typically, this is a router that looks up domains in the DNS in order to
1215 find the hosts to which this address routes. If it succeeds, the address is
1216 assigned to a suitable SMTP transport; if it does not succeed, the router is
1217 configured to fail the address.
1219 The second router is reached only when the domain is recognized as one that
1220 &"belongs"& to the local host. This router does redirection &-- also known as
1221 aliasing and forwarding. When it generates one or more new addresses from the
1222 original, each of them is routed independently from the start. Otherwise, the
1223 router may cause an address to fail, or it may simply decline to handle the
1224 address, in which case the address is passed to the next router.
1226 The final router in many configurations is one that checks to see if the
1227 address belongs to a local mailbox. The precondition may involve a check to
1228 see if the local part is the name of a login account, or it may look up the
1229 local part in a file or a database. If its preconditions are not met, or if
1230 the router declines, we have reached the end of the routers. When this happens,
1231 the address is bounced.
1235 .section "Processing an address for verification" "SECID16"
1236 .cindex "router" "for verification"
1237 .cindex "verifying address" "overview"
1238 As well as being used to decide how to deliver to an address, Exim's routers
1239 are also used for &'address verification'&. Verification can be requested as
1240 one of the checks to be performed in an ACL for incoming messages, on both
1241 sender and recipient addresses, and it can be tested using the &%-bv%& and
1242 &%-bvs%& command line options.
1244 When an address is being verified, the routers are run in &"verify mode"&. This
1245 does not affect the way the routers work, but it is a state that can be
1246 detected. By this means, a router can be skipped or made to behave differently
1247 when verifying. A common example is a configuration in which the first router
1248 sends all messages to a message-scanning program, unless they have been
1249 previously scanned. Thus, the first router accepts all addresses without any
1250 checking, making it useless for verifying. Normally, the &%no_verify%& option
1251 would be set for such a router, causing it to be skipped in verify mode.
1256 .section "Running an individual router" "SECTrunindrou"
1257 .cindex "router" "running details"
1258 .cindex "preconditions" "checking"
1259 .cindex "router" "result of running"
1260 As explained in the example above, a number of preconditions are checked before
1261 running a router. If any are not met, the router is skipped, and the address is
1262 passed to the next router. When all the preconditions on a router &'are'& met,
1263 the router is run. What happens next depends on the outcome, which is one of
1264 the following:
1266 .ilist
1267 &'accept'&: The router accepts the address, and either assigns it to a
1268 transport, or generates one or more &"child"& addresses. Processing the
1269 original address ceases,
1270 .oindex "&%unseen%&"
1271 unless the &%unseen%& option is set on the router. This option
1272 can be used to set up multiple deliveries with different routing (for example,
1273 for keeping archive copies of messages). When &%unseen%& is set, the address is
1274 passed to the next router. Normally, however, an &'accept'& return marks the
1275 end of routing.
1277 Any child addresses generated by the router are processed independently,
1278 starting with the first router by default. It is possible to change this by
1279 setting the &%redirect_router%& option to specify which router to start at for
1280 child addresses. Unlike &%pass_router%& (see below) the router specified by
1281 &%redirect_router%& may be anywhere in the router configuration.
1282 .next
1283 &'pass'&: The router recognizes the address, but cannot handle it itself. It
1284 requests that the address be passed to another router. By default the address
1285 is passed to the next router, but this can be changed by setting the
1286 &%pass_router%& option. However, (unlike &%redirect_router%&) the named router
1287 must be below the current router (to avoid loops).
1288 .next
1289 &'decline'&: The router declines to accept the address because it does not
1290 recognize it at all. By default, the address is passed to the next router, but
1291 this can be prevented by setting the &%no_more%& option. When &%no_more%& is
1292 set, all the remaining routers are skipped. In effect, &%no_more%& converts
1293 &'decline'& into &'fail'&.
1294 .next
1295 &'fail'&: The router determines that the address should fail, and queues it for
1296 the generation of a bounce message. There is no further processing of the
1297 original address unless &%unseen%& is set on the router.
1298 .next
1299 &'defer'&: The router cannot handle the address at the present time. (A
1300 database may be offline, or a DNS lookup may have timed out.) No further
1301 processing of the address happens in this delivery attempt. It is tried again
1302 next time the message is considered for delivery.
1303 .next
1304 &'error'&: There is some error in the router (for example, a syntax error in
1305 its configuration). The action is as for defer.
1306 .endlist
1308 If an address reaches the end of the routers without having been accepted by
1309 any of them, it is bounced as unrouteable. The default error message in this
1310 situation is &"unrouteable address"&, but you can set your own message by
1311 making use of the &%cannot_route_message%& option. This can be set for any
1312 router; the value from the last router that &"saw"& the address is used.
1314 Sometimes while routing you want to fail a delivery when some conditions are
1315 met but others are not, instead of passing the address on for further routing.
1316 You can do this by having a second router that explicitly fails the delivery
1317 when the relevant conditions are met. The &(redirect)& router has a &"fail"&
1318 facility for this purpose.
1321 .section "Duplicate addresses" "SECID17"
1322 .cindex "case of local parts"
1323 .cindex "address duplicate, discarding"
1324 .cindex "duplicate addresses"
1325 Once routing is complete, Exim scans the addresses that are assigned to local
1326 and remote transports, and discards any duplicates that it finds. During this
1327 check, local parts are treated as case-sensitive. This happens only when
1328 actually delivering a message; when testing routers with &%-bt%&, all the
1329 routed addresses are shown.
1333 .section "Router preconditions" "SECTrouprecon"
1334 .cindex "router" "preconditions, order of processing"
1335 .cindex "preconditions" "order of processing"
1336 The preconditions that are tested for each router are listed below, in the
1337 order in which they are tested. The individual configuration options are
1338 described in more detail in chapter &<<CHAProutergeneric>>&.
1340 .ilist
1341 The &%local_part_prefix%& and &%local_part_suffix%& options can specify that
1342 the local parts handled by the router may or must have certain prefixes and/or
1343 suffixes. If a mandatory affix (prefix or suffix) is not present, the router is
1344 skipped. These conditions are tested first. When an affix is present, it is
1345 removed from the local part before further processing, including the evaluation
1346 of any other conditions.
1347 .next
1348 Routers can be designated for use only when not verifying an address, that is,
1349 only when routing it for delivery (or testing its delivery routing). If the
1350 &%verify%& option is set false, the router is skipped when Exim is verifying an
1351 address.
1352 Setting the &%verify%& option actually sets two options, &%verify_sender%& and
1353 &%verify_recipient%&, which independently control the use of the router for
1354 sender and recipient verification. You can set these options directly if
1355 you want a router to be used for only one type of verification.
1356 .next
1357 If the &%address_test%& option is set false, the router is skipped when Exim is
1358 run with the &%-bt%& option to test an address routing. This can be helpful
1359 when the first router sends all new messages to a scanner of some sort; it
1360 makes it possible to use &%-bt%& to test subsequent delivery routing without
1361 having to simulate the effect of the scanner.
1362 .next
1363 Routers can be designated for use only when verifying an address, as
1364 opposed to routing it for delivery. The &%verify_only%& option controls this.
1365 .next
1366 Individual routers can be explicitly skipped when running the routers to
1367 check an address given in the SMTP EXPN command (see the &%expn%& option).
1368 .next
1369 If the &%domains%& option is set, the domain of the address must be in the set
1370 of domains that it defines.
1371 .next
1372 .vindex "&$local_part_prefix$&"
1373 .vindex "&$local_part$&"
1374 .vindex "&$local_part_suffix$&"
1375 If the &%local_parts%& option is set, the local part of the address must be in
1376 the set of local parts that it defines. If &%local_part_prefix%& or
1377 &%local_part_suffix%& is in use, the prefix or suffix is removed from the local
1378 part before this check. If you want to do precondition tests on local parts
1379 that include affixes, you can do so by using a &%condition%& option (see below)
1380 that uses the variables &$local_part$&, &$local_part_prefix$&, and
1381 &$local_part_suffix$& as necessary.
1382 .next
1383 .vindex "&$local_user_uid$&"
1384 .vindex "&$local_user_gid$&"
1385 .vindex "&$home$&"
1386 If the &%check_local_user%& option is set, the local part must be the name of
1387 an account on the local host. If this check succeeds, the uid and gid of the
1388 local user are placed in &$local_user_uid$& and &$local_user_gid$& and the
1389 user's home directory is placed in &$home$&; these values can be used in the
1390 remaining preconditions.
1391 .next
1392 If the &%router_home_directory%& option is set, it is expanded at this point,
1393 because it overrides the value of &$home$&. If this expansion were left till
1394 later, the value of &$home$& as set by &%check_local_user%& would be used in
1395 subsequent tests. Having two different values of &$home$& in the same router
1396 could lead to confusion.
1397 .next
1398 If the &%senders%& option is set, the envelope sender address must be in the
1399 set of addresses that it defines.
1400 .next
1401 If the &%require_files%& option is set, the existence or non-existence of
1402 specified files is tested.
1403 .next
1404 .cindex "customizing" "precondition"
1405 If the &%condition%& option is set, it is evaluated and tested. This option
1406 uses an expanded string to allow you to set up your own custom preconditions.
1407 Expanded strings are described in chapter &<<CHAPexpand>>&.
1408 .endlist
1411 Note that &%require_files%& comes near the end of the list, so you cannot use
1412 it to check for the existence of a file in which to lookup up a domain, local
1413 part, or sender. However, as these options are all expanded, you can use the
1414 &%exists%& expansion condition to make such tests within each condition. The
1415 &%require_files%& option is intended for checking files that the router may be
1416 going to use internally, or which are needed by a specific transport (for
1417 example, &_.procmailrc_&).
1421 .section "Delivery in detail" "SECID18"
1422 .cindex "delivery" "in detail"
1423 When a message is to be delivered, the sequence of events is as follows:
1425 .ilist
1426 If a system-wide filter file is specified, the message is passed to it. The
1427 filter may add recipients to the message, replace the recipients, discard the
1428 message, cause a new message to be generated, or cause the message delivery to
1429 fail. The format of the system filter file is the same as for Exim user filter
1430 files, described in the separate document entitled &'Exim's interfaces to mail
1431 filtering'&.
1432 .cindex "Sieve filter" "not available for system filter"
1433 (&*Note*&: Sieve cannot be used for system filter files.)
1435 Some additional features are available in system filters &-- see chapter
1436 &<<CHAPsystemfilter>>& for details. Note that a message is passed to the system
1437 filter only once per delivery attempt, however many recipients it has. However,
1438 if there are several delivery attempts because one or more addresses could not
1439 be immediately delivered, the system filter is run each time. The filter
1440 condition &%first_delivery%& can be used to detect the first run of the system
1441 filter.
1442 .next
1443 Each recipient address is offered to each configured router in turn, subject to
1444 its preconditions, until one is able to handle it. If no router can handle the
1445 address, that is, if they all decline, the address is failed. Because routers
1446 can be targeted at particular domains, several locally handled domains can be
1447 processed entirely independently of each other.
1448 .next
1449 .cindex "routing" "loops in"
1450 .cindex "loop" "while routing"
1451 A router that accepts an address may assign it to a local or a remote
1452 transport. However, the transport is not run at this time. Instead, the address
1453 is placed on a list for the particular transport, which will be run later.
1454 Alternatively, the router may generate one or more new addresses (typically
1455 from alias, forward, or filter files). New addresses are fed back into this
1456 process from the top, but in order to avoid loops, a router ignores any address
1457 which has an identically-named ancestor that was processed by itself.
1458 .next
1459 When all the routing has been done, addresses that have been successfully
1460 handled are passed to their assigned transports. When local transports are
1461 doing real local deliveries, they handle only one address at a time, but if a
1462 local transport is being used as a pseudo-remote transport (for example, to
1463 collect batched SMTP messages for transmission by some other means) multiple
1464 addresses can be handled. Remote transports can always handle more than one
1465 address at a time, but can be configured not to do so, or to restrict multiple
1466 addresses to the same domain.
1467 .next
1468 Each local delivery to a file or a pipe runs in a separate process under a
1469 non-privileged uid, and these deliveries are run one at a time. Remote
1470 deliveries also run in separate processes, normally under a uid that is private
1471 to Exim (&"the Exim user"&), but in this case, several remote deliveries can be
1472 run in parallel. The maximum number of simultaneous remote deliveries for any
1473 one message is set by the &%remote_max_parallel%& option.
1474 The order in which deliveries are done is not defined, except that all local
1475 deliveries happen before any remote deliveries.
1476 .next
1477 .cindex "queue runner"
1478 When it encounters a local delivery during a queue run, Exim checks its retry
1479 database to see if there has been a previous temporary delivery failure for the
1480 address before running the local transport. If there was a previous failure,
1481 Exim does not attempt a new delivery until the retry time for the address is
1482 reached. However, this happens only for delivery attempts that are part of a
1483 queue run. Local deliveries are always attempted when delivery immediately
1484 follows message reception, even if retry times are set for them. This makes for
1485 better behaviour if one particular message is causing problems (for example,
1486 causing quota overflow, or provoking an error in a filter file).
1487 .next
1488 .cindex "delivery" "retry in remote transports"
1489 Remote transports do their own retry handling, since an address may be
1490 deliverable to one of a number of hosts, each of which may have a different
1491 retry time. If there have been previous temporary failures and no host has
1492 reached its retry time, no delivery is attempted, whether in a queue run or
1493 not. See chapter &<<CHAPretry>>& for details of retry strategies.
1494 .next
1495 If there were any permanent errors, a bounce message is returned to an
1496 appropriate address (the sender in the common case), with details of the error
1497 for each failing address. Exim can be configured to send copies of bounce
1498 messages to other addresses.
1499 .next
1500 .cindex "delivery" "deferral"
1501 If one or more addresses suffered a temporary failure, the message is left on
1502 the queue, to be tried again later. Delivery of these addresses is said to be
1503 &'deferred'&.
1504 .next
1505 When all the recipient addresses have either been delivered or bounced,
1506 handling of the message is complete. The spool files and message log are
1507 deleted, though the message log can optionally be preserved if required.
1508 .endlist
1513 .section "Retry mechanism" "SECID19"
1514 .cindex "delivery" "retry mechanism"
1515 .cindex "retry" "description of mechanism"
1516 .cindex "queue runner"
1517 Exim's mechanism for retrying messages that fail to get delivered at the first
1518 attempt is the queue runner process. You must either run an Exim daemon that
1519 uses the &%-q%& option with a time interval to start queue runners at regular
1520 intervals, or use some other means (such as &'cron'&) to start them. If you do
1521 not arrange for queue runners to be run, messages that fail temporarily at the
1522 first attempt will remain on your queue for ever. A queue runner process works
1523 its way through the queue, one message at a time, trying each delivery that has
1524 passed its retry time.
1525 You can run several queue runners at once.
1527 Exim uses a set of configured rules to determine when next to retry the failing
1528 address (see chapter &<<CHAPretry>>&). These rules also specify when Exim
1529 should give up trying to deliver to the address, at which point it generates a
1530 bounce message. If no retry rules are set for a particular host, address, and
1531 error combination, no retries are attempted, and temporary errors are treated
1532 as permanent.
1536 .section "Temporary delivery failure" "SECID20"
1537 .cindex "delivery" "temporary failure"
1538 There are many reasons why a message may not be immediately deliverable to a
1539 particular address. Failure to connect to a remote machine (because it, or the
1540 connection to it, is down) is one of the most common. Temporary failures may be
1541 detected during routing as well as during the transport stage of delivery.
1542 Local deliveries may be delayed if NFS files are unavailable, or if a mailbox
1543 is on a file system where the user is over quota. Exim can be configured to
1544 impose its own quotas on local mailboxes; where system quotas are set they will
1545 also apply.
1547 If a host is unreachable for a period of time, a number of messages may be
1548 waiting for it by the time it recovers, and sending them in a single SMTP
1549 connection is clearly beneficial. Whenever a delivery to a remote host is
1550 deferred,
1552 .cindex "hints database"
1553 Exim makes a note in its hints database, and whenever a successful
1554 SMTP delivery has happened, it looks to see if any other messages are waiting
1555 for the same host. If any are found, they are sent over the same SMTP
1556 connection, subject to a configuration limit as to the maximum number in any
1557 one connection.
1562 .section "Permanent delivery failure" "SECID21"
1563 .cindex "delivery" "permanent failure"
1564 .cindex "bounce message" "when generated"
1565 When a message cannot be delivered to some or all of its intended recipients, a
1566 bounce message is generated. Temporary delivery failures turn into permanent
1567 errors when their timeout expires. All the addresses that fail in a given
1568 delivery attempt are listed in a single message. If the original message has
1569 many recipients, it is possible for some addresses to fail in one delivery
1570 attempt and others to fail subsequently, giving rise to more than one bounce
1571 message. The wording of bounce messages can be customized by the administrator.
1572 See chapter &<<CHAPemsgcust>>& for details.
1574 .cindex "&'X-Failed-Recipients:'& header line"
1575 Bounce messages contain an &'X-Failed-Recipients:'& header line that lists the
1576 failed addresses, for the benefit of programs that try to analyse such messages
1577 automatically.
1579 .cindex "bounce message" "recipient of"
1580 A bounce message is normally sent to the sender of the original message, as
1581 obtained from the message's envelope. For incoming SMTP messages, this is the
1582 address given in the MAIL command. However, when an address is expanded via a
1583 forward or alias file, an alternative address can be specified for delivery
1584 failures of the generated addresses. For a mailing list expansion (see section
1585 &<<SECTmailinglists>>&) it is common to direct bounce messages to the manager
1586 of the list.
1590 .section "Failures to deliver bounce messages" "SECID22"
1591 .cindex "bounce message" "failure to deliver"
1592 If a bounce message (either locally generated or received from a remote host)
1593 itself suffers a permanent delivery failure, the message is left on the queue,
1594 but it is frozen, awaiting the attention of an administrator. There are options
1595 that can be used to make Exim discard such failed messages, or to keep them
1596 for only a short time (see &%timeout_frozen_after%& and
1597 &%ignore_bounce_errors_after%&).
1603 . ////////////////////////////////////////////////////////////////////////////
1604 . ////////////////////////////////////////////////////////////////////////////
1606 .chapter "Building and installing Exim" "CHID3"
1607 .scindex IIDbuex "building Exim"
1609 .section "Unpacking" "SECID23"
1610 Exim is distributed as a gzipped or bzipped tar file which, when unpacked,
1611 creates a directory with the name of the current release (for example,
1612 &_exim-&version;_&) into which the following files are placed:
1614 .table2 140pt
1615 .irow &_ACKNOWLEDGMENTS_& "contains some acknowledgments"
1616 .irow &_CHANGES_& "contains a reference to where changes are &&&
1617 documented"
1618 .irow &_LICENCE_& "the GNU General Public Licence"
1619 .irow &_Makefile_& "top-level make file"
1620 .irow &_NOTICE_& "conditions for the use of Exim"
1621 .irow &_README_& "list of files, directories and simple build &&&
1622 instructions"
1623 .endtable
1625 Other files whose names begin with &_README_& may also be present. The
1626 following subdirectories are created:
1628 .table2 140pt
1629 .irow &_Local_& "an empty directory for local configuration files"
1630 .irow &_OS_& "OS-specific files"
1631 .irow &_doc_& "documentation files"
1632 .irow &_exim_monitor_& "source files for the Exim monitor"
1633 .irow &_scripts_& "scripts used in the build process"
1634 .irow &_src_& "remaining source files"
1635 .irow &_util_& "independent utilities"
1636 .endtable
1638 The main utility programs are contained in the &_src_& directory, and are built
1639 with the Exim binary. The &_util_& directory contains a few optional scripts
1640 that may be useful to some sites.
1643 .section "Multiple machine architectures and operating systems" "SECID24"
1644 .cindex "building Exim" "multiple OS/architectures"
1645 The building process for Exim is arranged to make it easy to build binaries for
1646 a number of different architectures and operating systems from the same set of
1647 source files. Compilation does not take place in the &_src_& directory.
1648 Instead, a &'build directory'& is created for each architecture and operating
1649 system.
1650 .cindex "symbolic link" "to build directory"
1651 Symbolic links to the sources are installed in this directory, which is where
1652 the actual building takes place. In most cases, Exim can discover the machine
1653 architecture and operating system for itself, but the defaults can be
1654 overridden if necessary.
1657 .section "DBM libraries" "SECTdb"
1658 .cindex "DBM libraries" "discussion of"
1659 .cindex "hints database" "DBM files used for"
1660 Even if you do not use any DBM files in your configuration, Exim still needs a
1661 DBM library in order to operate, because it uses indexed files for its hints
1662 databases. Unfortunately, there are a number of DBM libraries in existence, and
1663 different operating systems often have different ones installed.
1665 .cindex "Solaris" "DBM library for"
1666 .cindex "IRIX, DBM library for"
1667 .cindex "BSD, DBM library for"
1668 .cindex "Linux, DBM library for"
1669 If you are using Solaris, IRIX, one of the modern BSD systems, or a modern
1670 Linux distribution, the DBM configuration should happen automatically, and you
1671 may be able to ignore this section. Otherwise, you may have to learn more than
1672 you would like about DBM libraries from what follows.
1674 .cindex "&'ndbm'& DBM library"
1675 Licensed versions of Unix normally contain a library of DBM functions operating
1676 via the &'ndbm'& interface, and this is what Exim expects by default. Free
1677 versions of Unix seem to vary in what they contain as standard. In particular,
1678 some early versions of Linux have no default DBM library, and different
1679 distributors have chosen to bundle different libraries with their packaged
1680 versions. However, the more recent releases seem to have standardized on the
1681 Berkeley DB library.
1683 Different DBM libraries have different conventions for naming the files they
1684 use. When a program opens a file called &_dbmfile_&, there are several
1685 possibilities:
1687 .olist
1688 A traditional &'ndbm'& implementation, such as that supplied as part of
1689 Solaris, operates on two files called &_dbmfile.dir_& and &_dbmfile.pag_&.
1690 .next
1691 .cindex "&'gdbm'& DBM library"
1692 The GNU library, &'gdbm'&, operates on a single file. If used via its &'ndbm'&
1693 compatibility interface it makes two different hard links to it with names
1694 &_dbmfile.dir_& and &_dbmfile.pag_&, but if used via its native interface, the
1695 file name is used unmodified.
1696 .next
1697 .cindex "Berkeley DB library"
1698 The Berkeley DB package, if called via its &'ndbm'& compatibility interface,
1699 operates on a single file called &_dbmfile.db_&, but otherwise looks to the
1700 programmer exactly the same as the traditional &'ndbm'& implementation.
1701 .next
1702 If the Berkeley package is used in its native mode, it operates on a single
1703 file called &_dbmfile_&; the programmer's interface is somewhat different to
1704 the traditional &'ndbm'& interface.
1705 .next
1706 To complicate things further, there are several very different versions of the
1707 Berkeley DB package. Version 1.85 was stable for a very long time, releases
1708 2.&'x'& and 3.&'x'& were current for a while, but the latest versions are now
1709 numbered 4.&'x'&. Maintenance of some of the earlier releases has ceased. All
1710 versions of Berkeley DB can be obtained from
1711 &url(http://www.sleepycat.com/).
1712 .next
1713 .cindex "&'tdb'& DBM library"
1714 Yet another DBM library, called &'tdb'&, is available from
1715 &url(http://download.sourceforge.net/tdb). It has its own interface, and also
1716 operates on a single file.
1717 .endlist
1719 .cindex "USE_DB"
1720 .cindex "DBM libraries" "configuration for building"
1721 Exim and its utilities can be compiled to use any of these interfaces. In order
1722 to use any version of the Berkeley DB package in native mode, you must set
1723 USE_DB in an appropriate configuration file (typically
1724 &_Local/Makefile_&). For example:
1725 .code
1726 USE_DB=yes
1727 .endd
1728 Similarly, for gdbm you set USE_GDBM, and for tdb you set USE_TDB. An
1729 error is diagnosed if you set more than one of these.
1731 At the lowest level, the build-time configuration sets none of these options,
1732 thereby assuming an interface of type (1). However, some operating system
1733 configuration files (for example, those for the BSD operating systems and
1734 Linux) assume type (4) by setting USE_DB as their default, and the
1735 configuration files for Cygwin set USE_GDBM. Anything you set in
1736 &_Local/Makefile_&, however, overrides these system defaults.
1738 As well as setting USE_DB, USE_GDBM, or USE_TDB, it may also be
1739 necessary to set DBMLIB, to cause inclusion of the appropriate library, as
1740 in one of these lines:
1741 .code
1742 DBMLIB = -ldb
1743 DBMLIB = -ltdb
1744 .endd
1745 Settings like that will work if the DBM library is installed in the standard
1746 place. Sometimes it is not, and the library's header file may also not be in
1747 the default path. You may need to set INCLUDE to specify where the header
1748 file is, and to specify the path to the library more fully in DBMLIB, as in
1749 this example:
1750 .code
1751 INCLUDE=-I/usr/local/include/db-4.1
1752 DBMLIB=/usr/local/lib/db-4.1/libdb.a
1753 .endd
1754 There is further detailed discussion about the various DBM libraries in the
1755 file &_doc/dbm.discuss.txt_& in the Exim distribution.
1759 .section "Pre-building configuration" "SECID25"
1760 .cindex "building Exim" "pre-building configuration"
1761 .cindex "configuration for building Exim"
1762 .cindex "&_Local/Makefile_&"
1763 .cindex "&_src/EDITME_&"
1764 Before building Exim, a local configuration file that specifies options
1765 independent of any operating system has to be created with the name
1766 &_Local/Makefile_&. A template for this file is supplied as the file
1767 &_src/EDITME_&, and it contains full descriptions of all the option settings
1768 therein. These descriptions are therefore not repeated here. If you are
1769 building Exim for the first time, the simplest thing to do is to copy
1770 &_src/EDITME_& to &_Local/Makefile_&, then read it and edit it appropriately.
1772 There are three settings that you must supply, because Exim will not build
1773 without them. They are the location of the run time configuration file
1774 (CONFIGURE_FILE), the directory in which Exim binaries will be installed
1775 (BIN_DIRECTORY), and the identity of the Exim user (EXIM_USER and
1776 maybe EXIM_GROUP as well). The value of CONFIGURE_FILE can in fact be
1777 a colon-separated list of file names; Exim uses the first of them that exists.
1779 There are a few other parameters that can be specified either at build time or
1780 at run time, to enable the same binary to be used on a number of different
1781 machines. However, if the locations of Exim's spool directory and log file
1782 directory (if not within the spool directory) are fixed, it is recommended that
1783 you specify them in &_Local/Makefile_& instead of at run time, so that errors
1784 detected early in Exim's execution (such as a malformed configuration file) can
1785 be logged.
1787 .cindex "content scanning" "specifying at build time"
1788 Exim's interfaces for calling virus and spam scanning software directly from
1789 access control lists are not compiled by default. If you want to include these
1790 facilities, you need to set
1791 .code
1793 .endd
1794 in your &_Local/Makefile_&. For details of the facilities themselves, see
1795 chapter &<<CHAPexiscan>>&.
1798 .cindex "&_Local/eximon.conf_&"
1799 .cindex "&_exim_monitor/EDITME_&"
1800 If you are going to build the Exim monitor, a similar configuration process is
1801 required. The file &_exim_monitor/EDITME_& must be edited appropriately for
1802 your installation and saved under the name &_Local/eximon.conf_&. If you are
1803 happy with the default settings described in &_exim_monitor/EDITME_&,
1804 &_Local/eximon.conf_& can be empty, but it must exist.
1806 This is all the configuration that is needed in straightforward cases for known
1807 operating systems. However, the building process is set up so that it is easy
1808 to override options that are set by default or by operating-system-specific
1809 configuration files, for example to change the name of the C compiler, which
1810 defaults to &%gcc%&. See section &<<SECToverride>>& below for details of how to
1811 do this.
1815 .section "Support for iconv()" "SECID26"
1816 .cindex "&[iconv()]& support"
1817 .cindex "RFC 2047"
1818 The contents of header lines in messages may be encoded according to the rules
1819 described RFC 2047. This makes it possible to transmit characters that are not
1820 in the ASCII character set, and to label them as being in a particular
1821 character set. When Exim is inspecting header lines by means of the &%$h_%&
1822 mechanism, it decodes them, and translates them into a specified character set
1823 (default ISO-8859-1). The translation is possible only if the operating system
1824 supports the &[iconv()]& function.
1826 However, some of the operating systems that supply &[iconv()]& do not support
1827 very many conversions. The GNU &%libiconv%& library (available from
1828 &url(http://www.gnu.org/software/libiconv/)) can be installed on such
1829 systems to remedy this deficiency, as well as on systems that do not supply
1830 &[iconv()]& at all. After installing &%libiconv%&, you should add
1831 .code
1832 HAVE_ICONV=yes
1833 .endd
1834 to your &_Local/Makefile_& and rebuild Exim.
1838 .section "Including TLS/SSL encryption support" "SECTinctlsssl"
1839 .cindex "TLS" "including support for TLS"
1840 .cindex "encryption" "including support for"
1841 .cindex "SUPPORT_TLS"
1842 .cindex "OpenSSL" "building Exim with"
1843 .cindex "GnuTLS" "building Exim with"
1844 Exim can be built to support encrypted SMTP connections, using the STARTTLS
1845 command as per RFC 2487. It can also support legacy clients that expect to
1846 start a TLS session immediately on connection to a non-standard port (see the
1847 &%tls_on_connect_ports%& runtime option and the &%-tls-on-connect%& command
1848 line option).
1850 If you want to build Exim with TLS support, you must first install either the
1851 OpenSSL or GnuTLS library. There is no cryptographic code in Exim itself for
1852 implementing SSL.
1854 If OpenSSL is installed, you should set
1855 .code
1856 SUPPORT_TLS=yes
1857 TLS_LIBS=-lssl -lcrypto
1858 .endd
1859 in &_Local/Makefile_&. You may also need to specify the locations of the
1860 OpenSSL library and include files. For example:
1861 .code
1862 SUPPORT_TLS=yes
1863 TLS_LIBS=-L/usr/local/openssl/lib -lssl -lcrypto
1864 TLS_INCLUDE=-I/usr/local/openssl/include/
1865 .endd
1866 .cindex "USE_GNUTLS"
1867 If GnuTLS is installed, you should set
1868 .code
1869 SUPPORT_TLS=yes
1870 USE_GNUTLS=yes
1871 TLS_LIBS=-lgnutls -ltasn1 -lgcrypt
1872 .endd
1873 in &_Local/Makefile_&, and again you may need to specify the locations of the
1874 library and include files. For example:
1875 .code
1876 SUPPORT_TLS=yes
1877 USE_GNUTLS=yes
1878 TLS_LIBS=-L/usr/gnu/lib -lgnutls -ltasn1 -lgcrypt
1879 TLS_INCLUDE=-I/usr/gnu/include
1880 .endd
1881 You do not need to set TLS_INCLUDE if the relevant directory is already
1882 specified in INCLUDE. Details of how to configure Exim to make use of TLS are
1883 given in chapter &<<CHAPTLS>>&.
1888 .section "Use of tcpwrappers" "SECID27"
1889 .cindex "tcpwrappers, building Exim to support"
1890 .cindex "USE_TCP_WRAPPERS"
1891 Exim can be linked with the &'tcpwrappers'& library in order to check incoming
1892 SMTP calls using the &'tcpwrappers'& control files. This may be a convenient
1893 alternative to Exim's own checking facilities for installations that are
1894 already making use of &'tcpwrappers'& for other purposes. To do this, you
1895 should set USE_TCP_WRAPPERS in &_Local/Makefile_&, arrange for the file
1896 &_tcpd.h_& to be available at compile time, and also ensure that the library
1897 &_libwrap.a_& is available at link time, typically by including &%-lwrap%& in
1898 EXTRALIBS_EXIM. For example, if &'tcpwrappers'& is installed in &_/usr/local_&,
1899 you might have
1900 .code
1902 CFLAGS=-O -I/usr/local/include
1903 EXTRALIBS_EXIM=-L/usr/local/lib -lwrap
1904 .endd
1905 in &_Local/Makefile_&. The name to use in the &'tcpwrappers'& control files is
1906 &"exim"&. For example, the line
1907 .code
1908 exim : LOCAL 192.168.1. .friendly.domain.example
1909 .endd
1910 in your &_/etc/hosts.allow_& file allows connections from the local host, from
1911 the subnet, and from all hosts in &'friendly.domain.example'&.
1912 All other connections are denied. Consult the &'tcpwrappers'& documentation for
1913 further details.
1917 .section "Including support for IPv6" "SECID28"
1918 .cindex "IPv6" "including support for"
1919 Exim contains code for use on systems that have IPv6 support. Setting
1920 &`HAVE_IPV6=YES`& in &_Local/Makefile_& causes the IPv6 code to be included;
1921 it may also be necessary to set IPV6_INCLUDE and IPV6_LIBS on systems
1922 where the IPv6 support is not fully integrated into the normal include and
1923 library files.
1925 Two different types of DNS record for handling IPv6 addresses have been
1926 defined. AAAA records (analogous to A records for IPv4) are in use, and are
1927 currently seen as the mainstream. Another record type called A6 was proposed
1928 as better than AAAA because it had more flexibility. However, it was felt to be
1929 over-complex, and its status was reduced to &"experimental"&. It is not known
1930 if anyone is actually using A6 records. Exim has support for A6 records, but
1931 this is included only if you set &`SUPPORT_A6=YES`& in &_Local/Makefile_&. The
1932 support has not been tested for some time.
1936 .section "The building process" "SECID29"
1937 .cindex "build directory"
1938 Once &_Local/Makefile_& (and &_Local/eximon.conf_&, if required) have been
1939 created, run &'make'& at the top level. It determines the architecture and
1940 operating system types, and creates a build directory if one does not exist.
1941 For example, on a Sun system running Solaris 8, the directory
1942 &_build-SunOS5-5.8-sparc_& is created.
1943 .cindex "symbolic link" "to source files"
1944 Symbolic links to relevant source files are installed in the build directory.
1946 &*Warning*&: The &%-j%& (parallel) flag must not be used with &'make'&; the
1947 building process fails if it is set.
1949 If this is the first time &'make'& has been run, it calls a script that builds
1950 a make file inside the build directory, using the configuration files from the
1951 &_Local_& directory. The new make file is then passed to another instance of
1952 &'make'&. This does the real work, building a number of utility scripts, and
1953 then compiling and linking the binaries for the Exim monitor (if configured), a
1954 number of utility programs, and finally Exim itself. The command &`make
1955 makefile`& can be used to force a rebuild of the make file in the build
1956 directory, should this ever be necessary.
1958 If you have problems building Exim, check for any comments there may be in the
1959 &_README_& file concerning your operating system, and also take a look at the
1960 FAQ, where some common problems are covered.
1964 .section 'Output from &"make"&' "SECID283"
1965 The output produced by the &'make'& process for compile lines is often very
1966 unreadable, because these lines can be very long. For this reason, the normal
1967 output is suppressed by default, and instead output similar to that which
1968 appears when compiling the 2.6 Linux kernel is generated: just a short line for
1969 each module that is being compiled or linked. However, it is still possible to
1970 get the full output, by calling &'make'& like this:
1971 .code
1972 FULLECHO='' make -e
1973 .endd
1974 The value of FULLECHO defaults to &"@"&, the flag character that suppresses
1975 command reflection in &'make'&. When you ask for the full output, it is
1976 given in addition to the short output.
1980 .section "Overriding build-time options for Exim" "SECToverride"
1981 .cindex "build-time options, overriding"
1982 The main make file that is created at the beginning of the building process
1983 consists of the concatenation of a number of files which set configuration
1984 values, followed by a fixed set of &'make'& instructions. If a value is set
1985 more than once, the last setting overrides any previous ones. This provides a
1986 convenient way of overriding defaults. The files that are concatenated are, in
1987 order:
1988 .display
1989 &_OS/Makefile-Default_&
1990 &_OS/Makefile-_&<&'ostype'&>
1991 &_Local/Makefile_&
1992 &_Local/Makefile-_&<&'ostype'&>
1993 &_Local/Makefile-_&<&'archtype'&>
1994 &_Local/Makefile-_&<&'ostype'&>-<&'archtype'&>
1995 &_OS/Makefile-Base_&
1996 .endd
1997 .cindex "&_Local/Makefile_&"
1998 .cindex "building Exim" "operating system type"
1999 .cindex "building Exim" "architecture type"
2000 where <&'ostype'&> is the operating system type and <&'archtype'&> is the
2001 architecture type. &_Local/Makefile_& is required to exist, and the building
2002 process fails if it is absent. The other three &_Local_& files are optional,
2003 and are often not needed.
2005 The values used for <&'ostype'&> and <&'archtype'&> are obtained from scripts
2006 called &_scripts/os-type_& and &_scripts/arch-type_& respectively. If either of
2007 the environment variables EXIM_OSTYPE or EXIM_ARCHTYPE is set, their
2008 values are used, thereby providing a means of forcing particular settings.
2009 Otherwise, the scripts try to get values from the &%uname%& command. If this
2010 fails, the shell variables OSTYPE and ARCHTYPE are inspected. A number
2011 of &'ad hoc'& transformations are then applied, to produce the standard names
2012 that Exim expects. You can run these scripts directly from the shell in order
2013 to find out what values are being used on your system.
2016 &_OS/Makefile-Default_& contains comments about the variables that are set
2017 therein. Some (but not all) are mentioned below. If there is something that
2018 needs changing, review the contents of this file and the contents of the make
2019 file for your operating system (&_OS/Makefile-<ostype>_&) to see what the
2020 default values are.
2023 .cindex "building Exim" "overriding default settings"
2024 If you need to change any of the values that are set in &_OS/Makefile-Default_&
2025 or in &_OS/Makefile-<ostype>_&, or to add any new definitions, you do not
2026 need to change the original files. Instead, you should make the changes by
2027 putting the new values in an appropriate &_Local_& file. For example,
2028 .cindex "Tru64-Unix build-time settings"
2029 when building Exim in many releases of the Tru64-Unix (formerly Digital UNIX,
2030 formerly DEC-OSF1) operating system, it is necessary to specify that the C
2031 compiler is called &'cc'& rather than &'gcc'&. Also, the compiler must be
2032 called with the option &%-std1%&, to make it recognize some of the features of
2033 Standard C that Exim uses. (Most other compilers recognize Standard C by
2034 default.) To do this, you should create a file called &_Local/Makefile-OSF1_&
2035 containing the lines
2036 .code
2037 CC=cc
2038 CFLAGS=-std1
2039 .endd
2040 If you are compiling for just one operating system, it may be easier to put
2041 these lines directly into &_Local/Makefile_&.
2043 Keeping all your local configuration settings separate from the distributed
2044 files makes it easy to transfer them to new versions of Exim simply by copying
2045 the contents of the &_Local_& directory.
2048 .cindex "NIS lookup type" "including support for"
2049 .cindex "NIS+ lookup type" "including support for"
2050 .cindex "LDAP" "including support for"
2051 .cindex "lookup" "inclusion in binary"
2052 Exim contains support for doing LDAP, NIS, NIS+, and other kinds of file
2053 lookup, but not all systems have these components installed, so the default is
2054 not to include the relevant code in the binary. All the different kinds of file
2055 and database lookup that Exim supports are implemented as separate code modules
2056 which are included only if the relevant compile-time options are set. In the
2057 case of LDAP, NIS, and NIS+, the settings for &_Local/Makefile_& are:
2058 .code
2059 LOOKUP_LDAP=yes
2060 LOOKUP_NIS=yes
2062 .endd
2063 and similar settings apply to the other lookup types. They are all listed in
2064 &_src/EDITME_&. In many cases the relevant include files and interface
2065 libraries need to be installed before compiling Exim.
2066 .cindex "cdb" "including support for"
2067 However, there are some optional lookup types (such as cdb) for which
2068 the code is entirely contained within Exim, and no external include
2069 files or libraries are required. When a lookup type is not included in the
2070 binary, attempts to configure Exim to use it cause run time configuration
2071 errors.
2073 .cindex "Perl" "including support for"
2074 Exim can be linked with an embedded Perl interpreter, allowing Perl
2075 subroutines to be called during string expansion. To enable this facility,
2076 .code
2077 EXIM_PERL=perl.o
2078 .endd
2079 must be defined in &_Local/Makefile_&. Details of this facility are given in
2080 chapter &<<CHAPperl>>&.
2082 .cindex "X11 libraries, location of"
2083 The location of the X11 libraries is something that varies a lot between
2084 operating systems, and there may be different versions of X11 to cope
2085 with. Exim itself makes no use of X11, but if you are compiling the Exim
2086 monitor, the X11 libraries must be available.
2087 The following three variables are set in &_OS/Makefile-Default_&:
2088 .code
2089 X11=/usr/X11R6
2090 XINCLUDE=-I$(X11)/include
2091 XLFLAGS=-L$(X11)/lib
2092 .endd
2093 These are overridden in some of the operating-system configuration files. For
2094 example, in &_OS/Makefile-SunOS5_& there is
2095 .code
2096 X11=/usr/openwin
2097 XINCLUDE=-I$(X11)/include
2098 XLFLAGS=-L$(X11)/lib -R$(X11)/lib
2099 .endd
2100 If you need to override the default setting for your operating system, place a
2101 definition of all three of these variables into your
2102 &_Local/Makefile-<ostype>_& file.
2104 .cindex "EXTRALIBS"
2105 If you need to add any extra libraries to the link steps, these can be put in a
2106 variable called EXTRALIBS, which appears in all the link commands, but by
2107 default is not defined. In contrast, EXTRALIBS_EXIM is used only on the
2108 command for linking the main Exim binary, and not for any associated utilities.
2110 .cindex "DBM libraries" "configuration for building"
2111 There is also DBMLIB, which appears in the link commands for binaries that
2112 use DBM functions (see also section &<<SECTdb>>&). Finally, there is
2113 EXTRALIBS_EXIMON, which appears only in the link step for the Exim monitor
2114 binary, and which can be used, for example, to include additional X11
2115 libraries.
2117 .cindex "configuration file" "editing"
2118 The make file copes with rebuilding Exim correctly if any of the configuration
2119 files are edited. However, if an optional configuration file is deleted, it is
2120 necessary to touch the associated non-optional file (that is,
2121 &_Local/Makefile_& or &_Local/eximon.conf_&) before rebuilding.
2124 .section "OS-specific header files" "SECID30"
2125 .cindex "&_os.h_&"
2126 .cindex "building Exim" "OS-specific C header files"
2127 The &_OS_& directory contains a number of files with names of the form
2128 &_os.h-<ostype>_&. These are system-specific C header files that should not
2129 normally need to be changed. There is a list of macro settings that are
2130 recognized in the file &_OS/os.configuring_&, which should be consulted if you
2131 are porting Exim to a new operating system.
2135 .section "Overriding build-time options for the monitor" "SECID31"
2136 .cindex "building Eximon"
2137 A similar process is used for overriding things when building the Exim monitor,
2138 where the files that are involved are
2139 .display
2140 &_OS/eximon.conf-Default_&
2141 &_OS/eximon.conf-_&<&'ostype'&>
2142 &_Local/eximon.conf_&
2143 &_Local/eximon.conf-_&<&'ostype'&>
2144 &_Local/eximon.conf-_&<&'archtype'&>
2145 &_Local/eximon.conf-_&<&'ostype'&>-<&'archtype'&>
2146 .endd
2147 .cindex "&_Local/eximon.conf_&"
2148 As with Exim itself, the final three files need not exist, and in this case the
2149 &_OS/eximon.conf-<ostype>_& file is also optional. The default values in
2150 &_OS/eximon.conf-Default_& can be overridden dynamically by setting environment
2151 variables of the same name, preceded by EXIMON_. For example, setting
2152 EXIMON_LOG_DEPTH in the environment overrides the value of
2153 LOG_DEPTH at run time.
2154 .ecindex IIDbuex
2157 .section "Installing Exim binaries and scripts" "SECID32"
2158 .cindex "installing Exim"
2159 .cindex "BIN_DIRECTORY"
2160 The command &`make install`& runs the &(exim_install)& script with no
2161 arguments. The script copies binaries and utility scripts into the directory
2162 whose name is specified by the BIN_DIRECTORY setting in &_Local/Makefile_&.
2163 .cindex "setuid" "installing Exim with"
2164 The install script copies files only if they are newer than the files they are
2165 going to replace. The Exim binary is required to be owned by root and have the
2166 &'setuid'& bit set, for normal configurations. Therefore, you must run &`make
2167 install`& as root so that it can set up the Exim binary in this way. However, in
2168 some special situations (for example, if a host is doing no local deliveries)
2169 it may be possible to run Exim without making the binary setuid root (see
2170 chapter &<<CHAPsecurity>>& for details).
2172 .cindex "CONFIGURE_FILE"
2173 Exim's run time configuration file is named by the CONFIGURE_FILE setting
2174 in &_Local/Makefile_&. If this names a single file, and the file does not
2175 exist, the default configuration file &_src/configure.default_& is copied there
2176 by the installation script. If a run time configuration file already exists, it
2177 is left alone. If CONFIGURE_FILE is a colon-separated list, naming several
2178 alternative files, no default is installed.
2180 .cindex "system aliases file"
2181 .cindex "&_/etc/aliases_&"
2182 One change is made to the default configuration file when it is installed: the
2183 default configuration contains a router that references a system aliases file.
2184 The path to this file is set to the value specified by
2185 SYSTEM_ALIASES_FILE in &_Local/Makefile_& (&_/etc/aliases_& by default).
2186 If the system aliases file does not exist, the installation script creates it,
2187 and outputs a comment to the user.
2189 The created file contains no aliases, but it does contain comments about the
2190 aliases a site should normally have. Mail aliases have traditionally been
2191 kept in &_/etc/aliases_&. However, some operating systems are now using
2192 &_/etc/mail/aliases_&. You should check if yours is one of these, and change
2193 Exim's configuration if necessary.
2195 The default configuration uses the local host's name as the only local domain,
2196 and is set up to do local deliveries into the shared directory &_/var/mail_&,
2197 running as the local user. System aliases and &_.forward_& files in users' home
2198 directories are supported, but no NIS or NIS+ support is configured. Domains
2199 other than the name of the local host are routed using the DNS, with delivery
2200 over SMTP.
2202 It is possible to install Exim for special purposes (such as building a binary
2203 distribution) in a private part of the file system. You can do this by a
2204 command such as
2205 .code
2206 make DESTDIR=/some/directory/ install
2207 .endd
2208 This has the effect of pre-pending the specified directory to all the file
2209 paths, except the name of the system aliases file that appears in the default
2210 configuration. (If a default alias file is created, its name &'is'& modified.)
2211 For backwards compatibility, ROOT is used if DESTDIR is not set,
2212 but this usage is deprecated.
2214 .cindex "installing Exim" "what is not installed"
2215 Running &'make install'& does not copy the Exim 4 conversion script
2216 &'convert4r4'&, or the &'pcretest'& test program. You will probably run the
2217 first of these only once (if you are upgrading from Exim 3), and the second
2218 isn't really part of Exim. None of the documentation files in the &_doc_&
2219 directory are copied, except for the info files when you have set
2220 INFO_DIRECTORY, as described in section &<<SECTinsinfdoc>>& below.
2222 For the utility programs, old versions are renamed by adding the suffix &_.O_&
2223 to their names. The Exim binary itself, however, is handled differently. It is
2224 installed under a name that includes the version number and the compile number,
2225 for example &_exim-&version;-1_&. The script then arranges for a symbolic link
2226 called &_exim_& to point to the binary. If you are updating a previous version
2227 of Exim, the script takes care to ensure that the name &_exim_& is never absent
2228 from the directory (as seen by other processes).
2230 .cindex "installing Exim" "testing the script"
2231 If you want to see what the &'make install'& will do before running it for
2232 real, you can pass the &%-n%& option to the installation script by this
2233 command:
2234 .code
2235 make INSTALL_ARG=-n install
2236 .endd
2237 The contents of the variable INSTALL_ARG are passed to the installation
2238 script. You do not need to be root to run this test. Alternatively, you can run
2239 the installation script directly, but this must be from within the build
2240 directory. For example, from the top-level Exim directory you could use this
2241 command:
2242 .code
2243 (cd build-SunOS5-5.5.1-sparc; ../scripts/exim_install -n)
2244 .endd
2245 .cindex "installing Exim" "install script options"
2246 There are two other options that can be supplied to the installation script.
2248 .ilist
2249 &%-no_chown%& bypasses the call to change the owner of the installed binary
2250 to root, and the call to make it a setuid binary.
2251 .next
2252 &%-no_symlink%& bypasses the setting up of the symbolic link &_exim_& to the
2253 installed binary.
2254 .endlist
2256 INSTALL_ARG can be used to pass these options to the script. For example:
2257 .code
2258 make INSTALL_ARG=-no_symlink install
2259 .endd
2260 The installation script can also be given arguments specifying which files are
2261 to be copied. For example, to install just the Exim binary, and nothing else,
2262 without creating the symbolic link, you could use:
2263 .code
2264 make INSTALL_ARG='-no_symlink exim' install
2265 .endd
2269 .section "Installing info documentation" "SECTinsinfdoc"
2270 .cindex "installing Exim" "&'info'& documentation"
2271 Not all systems use the GNU &'info'& system for documentation, and for this
2272 reason, the Texinfo source of Exim's documentation is not included in the main
2273 distribution. Instead it is available separately from the ftp site (see section
2274 &<<SECTavail>>&).
2276 If you have defined INFO_DIRECTORY in &_Local/Makefile_& and the Texinfo
2277 source of the documentation is found in the source tree, running &`make
2278 install`& automatically builds the info files and installs them.
2282 .section "Setting up the spool directory" "SECID33"
2283 .cindex "spool directory" "creating"
2284 When it starts up, Exim tries to create its spool directory if it does not
2285 exist. The Exim uid and gid are used for the owner and group of the spool
2286 directory. Sub-directories are automatically created in the spool directory as
2287 necessary.
2292 .section "Testing" "SECID34"
2293 .cindex "testing" "installation"
2294 Having installed Exim, you can check that the run time configuration file is
2295 syntactically valid by running the following command, which assumes that the
2296 Exim binary directory is within your PATH environment variable:
2297 .code
2298 exim -bV
2299 .endd
2300 If there are any errors in the configuration file, Exim outputs error messages.
2301 Otherwise it outputs the version number and build date,
2302 the DBM library that is being used, and information about which drivers and
2303 other optional code modules are included in the binary.
2304 Some simple routing tests can be done by using the address testing option. For
2305 example,
2306 .display
2307 &`exim -bt`& <&'local username'&>
2308 .endd
2309 should verify that it recognizes a local mailbox, and
2310 .display
2311 &`exim -bt`& <&'remote address'&>
2312 .endd
2313 a remote one. Then try getting it to deliver mail, both locally and remotely.
2314 This can be done by passing messages directly to Exim, without going through a
2315 user agent. For example:
2316 .code
2317 exim -v postmaster@your.domain.example
2318 From: user@your.domain.example
2319 To: postmaster@your.domain.example
2320 Subject: Testing Exim
2322 This is a test message.
2323 ^D
2324 .endd
2325 The &%-v%& option causes Exim to output some verification of what it is doing.
2326 In this case you should see copies of three log lines, one for the message's
2327 arrival, one for its delivery, and one containing &"Completed"&.
2329 .cindex "delivery" "problems with"
2330 If you encounter problems, look at Exim's log files (&'mainlog'& and
2331 &'paniclog'&) to see if there is any relevant information there. Another source
2332 of information is running Exim with debugging turned on, by specifying the
2333 &%-d%& option. If a message is stuck on Exim's spool, you can force a delivery
2334 with debugging turned on by a command of the form
2335 .display
2336 &`exim -d -M`& <&'exim-message-id'&>
2337 .endd
2338 You must be root or an &"admin user"& in order to do this. The &%-d%& option
2339 produces rather a lot of output, but you can cut this down to specific areas.
2340 For example, if you use &%-d-all+route%& only the debugging information
2341 relevant to routing is included. (See the &%-d%& option in chapter
2342 &<<CHAPcommandline>>& for more details.)
2344 .cindex '&"sticky"& bit'
2345 .cindex "lock files"
2346 One specific problem that has shown up on some sites is the inability to do
2347 local deliveries into a shared mailbox directory, because it does not have the
2348 &"sticky bit"& set on it. By default, Exim tries to create a lock file before
2349 writing to a mailbox file, and if it cannot create the lock file, the delivery
2350 is deferred. You can get round this either by setting the &"sticky bit"& on the
2351 directory, or by setting a specific group for local deliveries and allowing
2352 that group to create files in the directory (see the comments above the
2353 &(local_delivery)& transport in the default configuration file). Another
2354 approach is to configure Exim not to use lock files, but just to rely on
2355 &[fcntl()]& locking instead. However, you should do this only if all user
2356 agents also use &[fcntl()]& locking. For further discussion of locking issues,
2357 see chapter &<<CHAPappendfile>>&.
2359 One thing that cannot be tested on a system that is already running an MTA is
2360 the receipt of incoming SMTP mail on the standard SMTP port. However, the
2361 &%-oX%& option can be used to run an Exim daemon that listens on some other
2362 port, or &'inetd'& can be used to do this. The &%-bh%& option and the
2363 &'exim_checkaccess'& utility can be used to check out policy controls on
2364 incoming SMTP mail.
2366 Testing a new version on a system that is already running Exim can most easily
2367 be done by building a binary with a different CONFIGURE_FILE setting. From
2368 within the run time configuration, all other file and directory names
2369 that Exim uses can be altered, in order to keep it entirely clear of the
2370 production version.
2373 .section "Replacing another MTA with Exim" "SECID35"
2374 .cindex "replacing another MTA"
2375 Building and installing Exim for the first time does not of itself put it in
2376 general use. The name by which the system's MTA is called by mail user agents
2377 is either &_/usr/sbin/sendmail_&, or &_/usr/lib/sendmail_& (depending on the
2378 operating system), and it is necessary to make this name point to the &'exim'&
2379 binary in order to get the user agents to pass messages to Exim. This is
2380 normally done by renaming any existing file and making &_/usr/sbin/sendmail_&
2381 or &_/usr/lib/sendmail_&
2382 .cindex "symbolic link" "to &'exim'& binary"
2383 a symbolic link to the &'exim'& binary. It is a good idea to remove any setuid
2384 privilege and executable status from the old MTA. It is then necessary to stop
2385 and restart the mailer daemon, if one is running.
2387 .cindex "FreeBSD, MTA indirection"
2388 .cindex "&_/etc/mail/mailer.conf_&"
2389 Some operating systems have introduced alternative ways of switching MTAs. For
2390 example, if you are running FreeBSD, you need to edit the file
2391 &_/etc/mail/mailer.conf_& instead of setting up a symbolic link as just
2392 described. A typical example of the contents of this file for running Exim is
2393 as follows:
2394 .code
2395 sendmail /usr/exim/bin/exim
2396 send-mail /usr/exim/bin/exim
2397 mailq /usr/exim/bin/exim -bp
2398 newaliases /usr/bin/true
2399 .endd
2400 Once you have set up the symbolic link, or edited &_/etc/mail/mailer.conf_&,
2401 your Exim installation is &"live"&. Check it by sending a message from your
2402 favourite user agent.
2404 You should consider what to tell your users about the change of MTA. Exim may
2405 have different capabilities to what was previously running, and there are
2406 various operational differences such as the text of messages produced by
2407 command line options and in bounce messages. If you allow your users to make
2408 use of Exim's filtering capabilities, you should make the document entitled
2409 &'Exim's interface to mail filtering'& available to them.
2413 .section "Upgrading Exim" "SECID36"
2414 .cindex "upgrading Exim"
2415 If you are already running Exim on your host, building and installing a new
2416 version automatically makes it available to MUAs, or any other programs that
2417 call the MTA directly. However, if you are running an Exim daemon, you do need
2418 to send it a HUP signal, to make it re-execute itself, and thereby pick up the
2419 new binary. You do not need to stop processing mail in order to install a new
2420 version of Exim. The install script does not modify an existing runtime
2421 configuration file.
2426 .section "Stopping the Exim daemon on Solaris" "SECID37"
2427 .cindex "Solaris" "stopping Exim on"
2428 The standard command for stopping the mailer daemon on Solaris is
2429 .code
2430 /etc/init.d/sendmail stop
2431 .endd
2432 If &_/usr/lib/sendmail_& has been turned into a symbolic link, this script
2433 fails to stop Exim because it uses the command &'ps -e'& and greps the output
2434 for the text &"sendmail"&; this is not present because the actual program name
2435 (that is, &"exim"&) is given by the &'ps'& command with these options. A
2436 solution is to replace the line that finds the process id with something like
2437 .code
2438 pid=`cat /var/spool/exim/exim-daemon.pid`
2439 .endd
2440 to obtain the daemon's pid directly from the file that Exim saves it in.
2442 Note, however, that stopping the daemon does not &"stop Exim"&. Messages can
2443 still be received from local processes, and if automatic delivery is configured
2444 (the normal case), deliveries will still occur.
2449 . ////////////////////////////////////////////////////////////////////////////
2450 . ////////////////////////////////////////////////////////////////////////////
2452 .chapter "The Exim command line" "CHAPcommandline"
2453 .scindex IIDclo1 "command line" "options"
2454 .scindex IIDclo2 "options" "command line"
2455 Exim's command line takes the standard Unix form of a sequence of options,
2456 each starting with a hyphen character, followed by a number of arguments. The
2457 options are compatible with the main options of Sendmail, and there are also
2458 some additional options, some of which are compatible with Smail 3. Certain
2459 combinations of options do not make sense, and provoke an error if used.
2460 The form of the arguments depends on which options are set.
2463 .section "Setting options by program name" "SECID38"
2464 .cindex "&'mailq'&"
2465 If Exim is called under the name &'mailq'&, it behaves as if the option &%-bp%&
2466 were present before any other options.
2467 The &%-bp%& option requests a listing of the contents of the mail queue on the
2468 standard output.
2469 This feature is for compatibility with some systems that contain a command of
2470 that name in one of the standard libraries, symbolically linked to
2471 &_/usr/sbin/sendmail_& or &_/usr/lib/sendmail_&.
2473 .cindex "&'rsmtp'&"
2474 If Exim is called under the name &'rsmtp'& it behaves as if the option &%-bS%&
2475 were present before any other options, for compatibility with Smail. The
2476 &%-bS%& option is used for reading in a number of messages in batched SMTP
2477 format.
2479 .cindex "&'rmail'&"
2480 If Exim is called under the name &'rmail'& it behaves as if the &%-i%& and
2481 &%-oee%& options were present before any other options, for compatibility with
2482 Smail. The name &'rmail'& is used as an interface by some UUCP systems.
2484 .cindex "&'runq'&"
2485 .cindex "queue runner"
2486 If Exim is called under the name &'runq'& it behaves as if the option &%-q%&
2487 were present before any other options, for compatibility with Smail. The &%-q%&
2488 option causes a single queue runner process to be started.
2490 .cindex "&'newaliases'&"
2491 .cindex "alias file" "building"
2492 .cindex "Sendmail compatibility" "calling Exim as &'newaliases'&"
2493 If Exim is called under the name &'newaliases'& it behaves as if the option
2494 &%-bi%& were present before any other options, for compatibility with Sendmail.
2495 This option is used for rebuilding Sendmail's alias file. Exim does not have
2496 the concept of a single alias file, but can be configured to run a given
2497 command if called with the &%-bi%& option.
2500 .section "Trusted and admin users" "SECTtrustedadmin"
2501 Some Exim options are available only to &'trusted users'& and others are
2502 available only to &'admin users'&. In the description below, the phrases &"Exim
2503 user"& and &"Exim group"& mean the user and group defined by EXIM_USER and
2504 EXIM_GROUP in &_Local/Makefile_& or set by the &%exim_user%& and
2505 &%exim_group%& options. These do not necessarily have to use the name &"exim"&.
2507 .ilist
2508 .cindex "trusted users" "definition of"
2509 .cindex "user" "trusted definition of"
2510 The trusted users are root, the Exim user, any user listed in the
2511 &%trusted_users%& configuration option, and any user whose current group or any
2512 supplementary group is one of those listed in the &%trusted_groups%&
2513 configuration option. Note that the Exim group is not automatically trusted.
2515 .cindex '&"From"& line'
2516 .cindex "envelope sender"
2517 Trusted users are always permitted to use the &%-f%& option or a leading
2518 &"From&~"& line to specify the envelope sender of a message that is passed to
2519 Exim through the local interface (see the &%-bm%& and &%-f%& options below).
2520 See the &%untrusted_set_sender%& option for a way of permitting non-trusted
2521 users to set envelope senders.
2523 .cindex "&'From:'& header line"
2524 .cindex "&'Sender:'& header line"
2525 For a trusted user, there is never any check on the contents of the &'From:'&
2526 header line, and a &'Sender:'& line is never added. Furthermore, any existing
2527 &'Sender:'& line in incoming local (non-TCP/IP) messages is not removed.
2529 Trusted users may also specify a host name, host address, interface address,
2530 protocol name, ident value, and authentication data when submitting a message
2531 locally. Thus, they are able to insert messages into Exim's queue locally that
2532 have the characteristics of messages received from a remote host. Untrusted
2533 users may in some circumstances use &%-f%&, but can never set the other values
2534 that are available to trusted users.
2535 .next
2536 .cindex "user" "admin definition of"
2537 .cindex "admin user" "definition of"
2538 The admin users are root, the Exim user, and any user that is a member of the
2539 Exim group or of any group listed in the &%admin_groups%& configuration option.
2540 The current group does not have to be one of these groups.
2542 Admin users are permitted to list the queue, and to carry out certain
2543 operations on messages, for example, to force delivery failures. It is also
2544 necessary to be an admin user in order to see the full information provided by
2545 the Exim monitor, and full debugging output.
2547 By default, the use of the &%-M%&, &%-q%&, &%-R%&, and &%-S%& options to cause
2548 Exim to attempt delivery of messages on its queue is restricted to admin users.
2549 However, this restriction can be relaxed by setting the &%prod_requires_admin%&
2550 option false (that is, specifying &%no_prod_requires_admin%&).
2552 Similarly, the use of the &%-bp%& option to list all the messages in the queue
2553 is restricted to admin users unless &%queue_list_requires_admin%& is set
2554 false.
2555 .endlist
2558 &*Warning*&: If you configure your system so that admin users are able to
2559 edit Exim's configuration file, you are giving those users an easy way of
2560 getting root. There is further discussion of this issue at the start of chapter
2561 &<<CHAPconf>>&.
2566 .section "Command line options" "SECID39"
2567 Exim's command line options are described in alphabetical order below. If none
2568 of the options that specifies a specific action (such as starting the daemon or
2569 a queue runner, or testing an address, or receiving a message in a specific
2570 format, or listing the queue) are present, and there is at least one argument
2571 on the command line, &%-bm%& (accept a local message on the standard input,
2572 with the arguments specifying the recipients) is assumed. Otherwise, Exim
2573 outputs a brief message about itself and exits.
2575 . ////////////////////////////////////////////////////////////////////////////
2576 . Insert a stylized XML comment here, to identify the start of the command line
2577 . options. This is for the benefit of the Perl script that automatically
2578 . creates a man page for the options.
2579 . ////////////////////////////////////////////////////////////////////////////
2581 .literal xml
2582 <!-- === Start of command line options === -->
2583 .literal off
2586 .vlist
2587 .vitem &%--%&
2588 .oindex "--"
2589 .cindex "options" "command line; terminating"
2590 This is a pseudo-option whose only purpose is to terminate the options and
2591 therefore to cause subsequent command line items to be treated as arguments
2592 rather than options, even if they begin with hyphens.
2594 .vitem &%--help%&
2595 .oindex "&%--help%&"
2596 This option causes Exim to output a few sentences stating what it is.
2597 The same output is generated if the Exim binary is called with no options and
2598 no arguments.
2600 .vitem &%-B%&<&'type'&>
2601 .oindex "&%-B%&"
2602 .cindex "8-bit characters"
2603 .cindex "Sendmail compatibility" "8-bit characters"
2604 This is a Sendmail option for selecting 7 or 8 bit processing. Exim is 8-bit
2605 clean; it ignores this option.
2607 .vitem &%-bd%&
2608 .oindex "&%-bd%&"
2609 .cindex "daemon"
2610 .cindex "SMTP" "listener"
2611 .cindex "queue runner"
2612 This option runs Exim as a daemon, awaiting incoming SMTP connections. Usually
2613 the &%-bd%& option is combined with the &%-q%&<&'time'&> option, to specify
2614 that the daemon should also initiate periodic queue runs.
2616 The &%-bd%& option can be used only by an admin user. If either of the &%-d%&
2617 (debugging) or &%-v%& (verifying) options are set, the daemon does not
2618 disconnect from the controlling terminal. When running this way, it can be
2619 stopped by pressing ctrl-C.
2621 By default, Exim listens for incoming connections to the standard SMTP port on
2622 all the host's running interfaces. However, it is possible to listen on other
2623 ports, on multiple ports, and only on specific interfaces. Chapter
2624 &<<CHAPinterfaces>>& contains a description of the options that control this.
2626 When a listening daemon
2627 .cindex "daemon" "process id (pid)"
2628 .cindex "pid (process id)" "of daemon"
2629 is started without the use of &%-oX%& (that is, without overriding the normal
2630 configuration), it writes its process id to a file called &_exim-daemon.pid_&
2631 in Exim's spool directory. This location can be overridden by setting
2632 PID_FILE_PATH in &_Local/Makefile_&. The file is written while Exim is still
2633 running as root.
2635 When &%-oX%& is used on the command line to start a listening daemon, the
2636 process id is not written to the normal pid file path. However, &%-oP%& can be
2637 used to specify a path on the command line if a pid file is required.
2639 The SIGHUP signal
2640 .cindex "SIGHUP"
2641 .cindex "daemon" "restarting"
2642 can be used to cause the daemon to re-execute itself. This should be done
2643 whenever Exim's configuration file, or any file that is incorporated into it by
2644 means of the &%.include%& facility, is changed, and also whenever a new version
2645 of Exim is installed. It is not necessary to do this when other files that are
2646 referenced from the configuration (for example, alias files) are changed,
2647 because these are reread each time they are used.
2649 .vitem &%-bdf%&
2650 .oindex "&%-bdf%&"
2651 This option has the same effect as &%-bd%& except that it never disconnects
2652 from the controlling terminal, even when no debugging is specified.
2654 .vitem &%-be%&
2655 .oindex "&%-be%&"
2656 .cindex "testing" "string expansion"
2657 .cindex "expansion" "testing"
2658 Run Exim in expansion testing mode. Exim discards its root privilege, to
2659 prevent ordinary users from using this mode to read otherwise inaccessible
2660 files. If no arguments are given, Exim runs interactively, prompting for lines
2661 of data. Otherwise, it processes each argument in turn.
2663 If Exim was built with USE_READLINE=yes in &_Local/Makefile_&, it tries
2664 to load the &%libreadline%& library dynamically whenever the &%-be%& option is
2665 used without command line arguments. If successful, it uses the &[readline()]&
2666 function, which provides extensive line-editing facilities, for reading the
2667 test data. A line history is supported.
2669 Long expansion expressions can be split over several lines by using backslash
2670 continuations. As in Exim's run time configuration, white space at the start of
2671 continuation lines is ignored. Each argument or data line is passed through the
2672 string expansion mechanism, and the result is output. Variable values from the
2673 configuration file (for example, &$qualify_domain$&) are available, but no
2674 message-specific values (such as &$sender_domain$&) are set, because no message
2675 is being processed (but see &%-bem%& and &%-Mset%&).
2677 &*Note*&: If you use this mechanism to test lookups, and you change the data
2678 files or databases you are using, you must exit and restart Exim before trying
2679 the same lookup again. Otherwise, because each Exim process caches the results
2680 of lookups, you will just get the same result as before.
2682 .vitem &%-bem%&&~<&'filename'&>
2683 .oindex "&%-bem%&"
2684 .cindex "testing" "string expansion"
2685 .cindex "expansion" "testing"
2686 This option operates like &%-be%& except that it must be followed by the name
2687 of a file. For example:
2688 .code
2689 exim -bem /tmp/testmessage
2690 .endd
2691 The file is read as a message (as if receiving a locally-submitted non-SMTP
2692 message) before any of the test expansions are done. Thus, message-specific
2693 variables such as &$message_size$& and &$header_from:$& are available. However,
2694 no &'Received:'& header is added to the message. If the &%-t%& option is set,
2695 recipients are read from the headers in the normal way, and are shown in the
2696 &$recipients$& variable. Note that recipients cannot be given on the command
2697 line, because further arguments are taken as strings to expand (just like
2698 &%-be%&).
2700 .vitem &%-bF%&&~<&'filename'&>
2701 .oindex "&%-bF%&"
2702 .cindex "system filter" "testing"
2703 .cindex "testing" "system filter"
2704 This option is the same as &%-bf%& except that it assumes that the filter being
2705 tested is a system filter. The additional commands that are available only in
2706 system filters are recognized.
2708 .vitem &%-bf%&&~<&'filename'&>
2709 .oindex "&%-bf%&"
2710 .cindex "filter" "testing"
2711 .cindex "testing" "filter file"
2712 .cindex "forward file" "testing"
2713 .cindex "testing" "forward file"
2714 .cindex "Sieve filter" "testing"
2715 This option runs Exim in user filter testing mode; the file is the filter file
2716 to be tested, and a test message must be supplied on the standard input. If
2717 there are no message-dependent tests in the filter, an empty file can be
2718 supplied.
2720 If you want to test a system filter file, use &%-bF%& instead of &%-bf%&. You
2721 can use both &%-bF%& and &%-bf%& on the same command, in order to test a system
2722 filter and a user filter in the same run. For example:
2723 .code
2724 exim -bF /system/filter -bf /user/filter </test/message
2725 .endd
2726 This is helpful when the system filter adds header lines or sets filter
2727 variables that are used by the user filter.
2729 If the test filter file does not begin with one of the special lines
2730 .code
2731 # Exim filter
2732 # Sieve filter
2733 .endd
2734 it is taken to be a normal &_.forward_& file, and is tested for validity under
2735 that interpretation. See sections &<<SECTitenonfilred>>& to
2736 &<<SECTspecitredli>>& for a description of the possible contents of non-filter
2737 redirection lists.
2739 The result of an Exim command that uses &%-bf%&, provided no errors are
2740 detected, is a list of the actions that Exim would try to take if presented
2741 with the message for real. More details of filter testing are given in the
2742 separate document entitled &'Exim's interfaces to mail filtering'&.
2744 When testing a filter file,
2745 .cindex "&""From""& line"
2746 .cindex "envelope sender"
2747 .oindex "&%-f%&" "for filter testing"
2748 the envelope sender can be set by the &%-f%& option,
2749 or by a &"From&~"& line at the start of the test message. Various parameters
2750 that would normally be taken from the envelope recipient address of the message
2751 can be set by means of additional command line options (see the next four
2752 options).
2754 .vitem &%-bfd%&&~<&'domain'&>
2755 .oindex "&%-bfd%&"
2756 .vindex "&$qualify_domain$&"
2757 This sets the domain of the recipient address when a filter file is being
2758 tested by means of the &%-bf%& option. The default is the value of
2759 &$qualify_domain$&.
2761 .vitem &%-bfl%&&~<&'local&~part'&>
2762 .oindex "&%-bfl%&"
2763 This sets the local part of the recipient address when a filter file is being
2764 tested by means of the &%-bf%& option. The default is the username of the
2765 process that calls Exim. A local part should be specified with any prefix or
2766 suffix stripped, because that is how it appears to the filter when a message is
2767 actually being delivered.
2769 .vitem &%-bfp%&&~<&'prefix'&>
2770 .oindex "&%-bfp%&"
2771 This sets the prefix of the local part of the recipient address when a filter
2772 file is being tested by means of the &%-bf%& option. The default is an empty
2773 prefix.
2775 .vitem &%-bfs%&&~<&'suffix'&>
2776 .oindex "&%-bfs%&"
2777 This sets the suffix of the local part of the recipient address when a filter
2778 file is being tested by means of the &%-bf%& option. The default is an empty
2779 suffix.
2781 .vitem &%-bh%&&~<&'IP&~address'&>
2782 .oindex "&%-bh%&"
2783 .cindex "testing" "incoming SMTP"
2784 .cindex "SMTP" "testing incoming"
2785 .cindex "testing" "relay control"
2786 .cindex "relaying" "testing configuration"
2787 .cindex "policy control" "testing"
2788 .cindex "debugging" "&%-bh%& option"
2789 This option runs a fake SMTP session as if from the given IP address, using the
2790 standard input and output. The IP address may include a port number at the end,
2791 after a full stop. For example:
2792 .code
2793 exim -bh
2794 exim -bh fe80::a00:20ff:fe86:a061.5678
2795 .endd
2796 When an IPv6 address is given, it is converted into canonical form. In the case
2797 of the second example above, the value of &$sender_host_address$& after
2798 conversion to the canonical form is
2799 &`fe80:0000:0000:0a00:20ff:fe86:a061.5678`&.
2801 Comments as to what is going on are written to the standard error file. These
2802 include lines beginning with &"LOG"& for anything that would have been logged.
2803 This facility is provided for testing configuration options for incoming
2804 messages, to make sure they implement the required policy. For example, you can
2805 test your relay controls using &%-bh%&.
2807 &*Warning 1*&:
2808 .cindex "RFC 1413"
2809 You can test features of the configuration that rely on ident (RFC 1413)
2810 information by using the &%-oMt%& option. However, Exim cannot actually perform
2811 an ident callout when testing using &%-bh%& because there is no incoming SMTP
2812 connection.
2814 &*Warning 2*&: Address verification callouts (see section &<<SECTcallver>>&)
2815 are also skipped when testing using &%-bh%&. If you want these callouts to
2816 occur, use &%-bhc%& instead.
2818 Messages supplied during the testing session are discarded, and nothing is
2819 written to any of the real log files. There may be pauses when DNS (and other)
2820 lookups are taking place, and of course these may time out. The &%-oMi%& option
2821 can be used to specify a specific IP interface and port if this is important,
2822 and &%-oMaa%& and &%-oMai%& can be used to set parameters as if the SMTP
2823 session were authenticated.
2825 The &'exim_checkaccess'& utility is a &"packaged"& version of &%-bh%& whose
2826 output just states whether a given recipient address from a given host is
2827 acceptable or not. See section &<<SECTcheckaccess>>&.
2829 Features such as authentication and encryption, where the client input is not
2830 plain text, cannot easily be tested with &%-bh%&. Instead, you should use a
2831 specialized SMTP test program such as
2832 &url(http://jetmore.org/john/code/#swaks,swaks).
2834 .vitem &%-bhc%&&~<&'IP&~address'&>
2835 .oindex "&%-bhc%&"
2836 This option operates in the same way as &%-bh%&, except that address
2837 verification callouts are performed if required. This includes consulting and
2838 updating the callout cache database.
2840 .vitem &%-bi%&
2841 .oindex "&%-bi%&"
2842 .cindex "alias file" "building"
2843 .cindex "building alias file"
2844 .cindex "Sendmail compatibility" "&%-bi%& option"
2845 Sendmail interprets the &%-bi%& option as a request to rebuild its alias file.
2846 Exim does not have the concept of a single alias file, and so it cannot mimic
2847 this behaviour. However, calls to &_/usr/lib/sendmail_& with the &%-bi%& option
2848 tend to appear in various scripts such as NIS make files, so the option must be
2849 recognized.
2851 If &%-bi%& is encountered, the command specified by the &%bi_command%&
2852 configuration option is run, under the uid and gid of the caller of Exim. If
2853 the &%-oA%& option is used, its value is passed to the command as an argument.
2854 The command set by &%bi_command%& may not contain arguments. The command can
2855 use the &'exim_dbmbuild'& utility, or some other means, to rebuild alias files
2856 if this is required. If the &%bi_command%& option is not set, calling Exim with
2857 &%-bi%& is a no-op.
2859 .vitem &%-bm%&
2860 .oindex "&%-bm%&"
2861 .cindex "local message reception"
2862 This option runs an Exim receiving process that accepts an incoming,
2863 locally-generated message on the current input. The recipients are given as the
2864 command arguments (except when &%-t%& is also present &-- see below). Each
2865 argument can be a comma-separated list of RFC 2822 addresses. This is the
2866 default option for selecting the overall action of an Exim call; it is assumed
2867 if no other conflicting option is present.
2869 If any addresses in the message are unqualified (have no domain), they are
2870 qualified by the values of the &%qualify_domain%& or &%qualify_recipient%&
2871 options, as appropriate. The &%-bnq%& option (see below) provides a way of
2872 suppressing this for special cases.
2874 Policy checks on the contents of local messages can be enforced by means of
2875 the non-SMTP ACL. See chapter &<<CHAPACL>>& for details.
2877 .cindex "return code" "for &%-bm%&"
2878 The return code is zero if the message is successfully accepted. Otherwise, the
2879 action is controlled by the &%-oe%&&'x'& option setting &-- see below.
2881 The format
2882 .cindex "message" "format"
2883 .cindex "format" "message"
2884 .cindex "&""From""& line"
2885 .cindex "UUCP" "&""From""& line"
2886 .cindex "Sendmail compatibility" "&""From""& line"
2887 of the message must be as defined in RFC 2822, except that, for
2888 compatibility with Sendmail and Smail, a line in one of the forms
2889 .code
2890 From sender Fri Jan 5 12:55 GMT 1997
2891 From sender Fri, 5 Jan 97 12:55:01
2892 .endd
2893 (with the weekday optional, and possibly with additional text after the date)
2894 is permitted to appear at the start of the message. There appears to be no
2895 authoritative specification of the format of this line. Exim recognizes it by
2896 matching against the regular expression defined by the &%uucp_from_pattern%&
2897 option, which can be changed if necessary.
2899 .oindex "&%-f%&" "overriding &""From""& line"
2900 The specified sender is treated as if it were given as the argument to the
2901 &%-f%& option, but if a &%-f%& option is also present, its argument is used in
2902 preference to the address taken from the message. The caller of Exim must be a
2903 trusted user for the sender of a message to be set in this way.
2905 .vitem &%-bnq%&
2906 .oindex "&%-bnq%&"
2907 .cindex "address qualification, suppressing"
2908 By default, Exim automatically qualifies unqualified addresses (those
2909 without domains) that appear in messages that are submitted locally (that
2910 is, not over TCP/IP). This qualification applies both to addresses in
2911 envelopes, and addresses in header lines. Sender addresses are qualified using
2912 &%qualify_domain%&, and recipient addresses using &%qualify_recipient%& (which
2913 defaults to the value of &%qualify_domain%&).
2915 Sometimes, qualification is not wanted. For example, if &%-bS%& (batch SMTP) is
2916 being used to re-submit messages that originally came from remote hosts after
2917 content scanning, you probably do not want to qualify unqualified addresses in
2918 header lines. (Such lines will be present only if you have not enabled a header
2919 syntax check in the appropriate ACL.)
2921 The &%-bnq%& option suppresses all qualification of unqualified addresses in
2922 messages that originate on the local host. When this is used, unqualified
2923 addresses in the envelope provoke errors (causing message rejection) and
2924 unqualified addresses in header lines are left alone.
2927 .vitem &%-bP%&
2928 .oindex "&%-bP%&"
2929 .cindex "configuration options" "extracting"
2930 .cindex "options" "configuration &-- extracting"
2931 If this option is given with no arguments, it causes the values of all Exim's
2932 main configuration options to be written to the standard output. The values
2933 of one or more specific options can be requested by giving their names as
2934 arguments, for example:
2935 .code
2936 exim -bP qualify_domain hold_domains
2937 .endd
2938 .cindex "hiding configuration option values"
2939 .cindex "configuration options" "hiding value of"
2940 .cindex "options" "hiding value of"
2941 However, any option setting that is preceded by the word &"hide"& in the
2942 configuration file is not shown in full, except to an admin user. For other
2943 users, the output is as in this example:
2944 .code
2945 mysql_servers = <value not displayable>
2946 .endd
2947 If &%configure_file%& is given as an argument, the name of the run time
2948 configuration file is output.
2949 If a list of configuration files was supplied, the value that is output here
2950 is the name of the file that was actually used.
2952 .cindex "daemon" "process id (pid)"
2953 .cindex "pid (process id)" "of daemon"
2954 If &%log_file_path%& or &%pid_file_path%& are given, the names of the
2955 directories where log files and daemon pid files are written are output,
2956 respectively. If these values are unset, log files are written in a
2957 sub-directory of the spool directory called &%log%&, and the pid file is
2958 written directly into the spool directory.
2960 If &%-bP%& is followed by a name preceded by &`+`&, for example,
2961 .code
2962 exim -bP +local_domains
2963 .endd
2964 it searches for a matching named list of any type (domain, host, address, or
2965 local part) and outputs what it finds.
2967 .cindex "options" "router &-- extracting"
2968 .cindex "options" "transport &-- extracting"
2969 If one of the words &%router%&, &%transport%&, or &%authenticator%& is given,
2970 followed by the name of an appropriate driver instance, the option settings for
2971 that driver are output. For example:
2972 .code
2973 exim -bP transport local_delivery
2974 .endd
2975 The generic driver options are output first, followed by the driver's private
2976 options. A list of the names of drivers of a particular type can be obtained by
2977 using one of the words &%router_list%&, &%transport_list%&, or
2978 &%authenticator_list%&, and a complete list of all drivers with their option
2979 settings can be obtained by using &%routers%&, &%transports%&, or
2980 &%authenticators%&.
2983 .vitem &%-bp%&
2984 .oindex "&%-bp%&"
2985 .cindex "queue" "listing messages on"
2986 .cindex "listing" "messages on the queue"
2987 This option requests a listing of the contents of the mail queue on the
2988 standard output. If the &%-bp%& option is followed by a list of message ids,
2989 just those messages are listed. By default, this option can be used only by an
2990 admin user. However, the &%queue_list_requires_admin%& option can be set false
2991 to allow any user to see the queue.
2993 Each message on the queue is displayed as in the following example:
2994 .code
2995 25m 2.9K 0t5C6f-0000c8-00 <alice@wonderland.fict.example>
2996 red.king@looking-glass.fict.example
2997 <other addresses>
2998 .endd
2999 .cindex "message" "size in queue listing"
3000 .cindex "size" "of message"
3001 The first line contains the length of time the message has been on the queue
3002 (in this case 25 minutes), the size of the message (2.9K), the unique local
3003 identifier for the message, and the message sender, as contained in the
3004 envelope. For bounce messages, the sender address is empty, and appears as
3005 &"<>"&. If the message was submitted locally by an untrusted user who overrode
3006 the default sender address, the user's login name is shown in parentheses
3007 before the sender address.
3009 .cindex "frozen messages" "in queue listing"
3010 If the message is frozen (attempts to deliver it are suspended) then the text
3011 &"*** frozen ***"& is displayed at the end of this line.
3013 The recipients of the message (taken from the envelope, not the headers) are
3014 displayed on subsequent lines. Those addresses to which the message has already
3015 been delivered are marked with the letter D. If an original address gets
3016 expanded into several addresses via an alias or forward file, the original is
3017 displayed with a D only when deliveries for all of its child addresses are
3018 complete.
3021 .vitem &%-bpa%&
3022 .oindex "&%-bpa%&"
3023 This option operates like &%-bp%&, but in addition it shows delivered addresses
3024 that were generated from the original top level address(es) in each message by
3025 alias or forwarding operations. These addresses are flagged with &"+D"& instead
3026 of just &"D"&.
3029 .vitem &%-bpc%&
3030 .oindex "&%-bpc%&"
3031 .cindex "queue" "count of messages on"
3032 This option counts the number of messages on the queue, and writes the total
3033 to the standard output. It is restricted to admin users, unless
3034 &%queue_list_requires_admin%& is set false.
3037 .vitem &%-bpr%&
3038 .oindex "&%-bpr%&"
3039 This option operates like &%-bp%&, but the output is not sorted into
3040 chronological order of message arrival. This can speed it up when there are
3041 lots of messages on the queue, and is particularly useful if the output is
3042 going to be post-processed in a way that doesn't need the sorting.
3044 .vitem &%-bpra%&
3045 .oindex "&%-bpra%&"
3046 This option is a combination of &%-bpr%& and &%-bpa%&.
3048 .vitem &%-bpru%&
3049 .oindex "&%-bpru%&"
3050 This option is a combination of &%-bpr%& and &%-bpu%&.
3053 .vitem &%-bpu%&
3054 .oindex "&%-bpu%&"
3055 This option operates like &%-bp%& but shows only undelivered top-level
3056 addresses for each message displayed. Addresses generated by aliasing or
3057 forwarding are not shown, unless the message was deferred after processing by a
3058 router with the &%one_time%& option set.
3061 .vitem &%-brt%&
3062 .oindex "&%-brt%&"
3063 .cindex "testing" "retry configuration"
3064 .cindex "retry" "configuration testing"
3065 This option is for testing retry rules, and it must be followed by up to three
3066 arguments. It causes Exim to look for a retry rule that matches the values
3067 and to write it to the standard output. For example:
3068 .code
3069 exim -brt bach.comp.mus.example
3070 Retry rule: *.comp.mus.example F,2h,15m; F,4d,30m;
3071 .endd
3072 See chapter &<<CHAPretry>>& for a description of Exim's retry rules. The first
3073 argument, which is required, can be a complete address in the form
3074 &'local_part@domain'&, or it can be just a domain name. If the second argument
3075 contains a dot, it is interpreted as an optional second domain name; if no
3076 retry rule is found for the first argument, the second is tried. This ties in
3077 with Exim's behaviour when looking for retry rules for remote hosts &-- if no
3078 rule is found that matches the host, one that matches the mail domain is
3079 sought. Finally, an argument that is the name of a specific delivery error, as
3080 used in setting up retry rules, can be given. For example:
3081 .code
3082 exim -brt haydn.comp.mus.example quota_3d
3083 Retry rule: *@haydn.comp.mus.example quota_3d F,1h,15m
3084 .endd
3086 .vitem &%-brw%&
3087 .oindex "&%-brw%&"
3088 .cindex "testing" "rewriting"
3089 .cindex "rewriting" "testing"
3090 This option is for testing address rewriting rules, and it must be followed by
3091 a single argument, consisting of either a local part without a domain, or a
3092 complete address with a fully qualified domain. Exim outputs how this address
3093 would be rewritten for each possible place it might appear. See chapter
3094 &<<CHAPrewrite>>& for further details.
3096 .vitem &%-bS%&
3097 .oindex "&%-bS%&"
3098 .cindex "SMTP" "batched incoming"
3099 .cindex "batched SMTP input"
3100 This option is used for batched SMTP input, which is an alternative interface
3101 for non-interactive local message submission. A number of messages can be
3102 submitted in a single run. However, despite its name, this is not really SMTP
3103 input. Exim reads each message's envelope from SMTP commands on the standard
3104 input, but generates no responses. If the caller is trusted, or
3105 &%untrusted_set_sender%& is set, the senders in the SMTP MAIL commands are
3106 believed; otherwise the sender is always the caller of Exim.
3108 The message itself is read from the standard input, in SMTP format (leading
3109 dots doubled), terminated by a line containing just a single dot. An error is
3110 provoked if the terminating dot is missing. A further message may then follow.
3112 As for other local message submissions, the contents of incoming batch SMTP
3113 messages can be checked using the non-SMTP ACL (see chapter &<<CHAPACL>>&).
3114 Unqualified addresses are automatically qualified using &%qualify_domain%& and
3115 &%qualify_recipient%&, as appropriate, unless the &%-bnq%& option is used.
3117 Some other SMTP commands are recognized in the input. HELO and EHLO act
3118 as RSET; VRFY, EXPN, ETRN, and HELP act as NOOP;
3119 QUIT quits, ignoring the rest of the standard input.
3121 .cindex "return code" "for &%-bS%&"
3122 If any error is encountered, reports are written to the standard output and
3123 error streams, and Exim gives up immediately. The return code is 0 if no error
3124 was detected; it is 1 if one or more messages were accepted before the error
3125 was detected; otherwise it is 2.
3127 More details of input using batched SMTP are given in section
3128 &<<SECTincomingbatchedSMTP>>&.
3130 .vitem &%-bs%&
3131 .oindex "&%-bs%&"
3132 .cindex "SMTP" "local input"
3133 .cindex "local SMTP input"
3134 This option causes Exim to accept one or more messages by reading SMTP commands
3135 on the standard input, and producing SMTP replies on the standard output. SMTP
3136 policy controls, as defined in ACLs (see chapter &<<CHAPACL>>&) are applied.
3137 Some user agents use this interface as a way of passing locally-generated
3138 messages to the MTA.
3140 In
3141 .cindex "sender" "source of"
3142 this usage, if the caller of Exim is trusted, or &%untrusted_set_sender%& is
3143 set, the senders of messages are taken from the SMTP MAIL commands.
3144 Otherwise the content of these commands is ignored and the sender is set up as
3145 the calling user. Unqualified addresses are automatically qualified using
3146 &%qualify_domain%& and &%qualify_recipient%&, as appropriate, unless the
3147 &%-bnq%& option is used.
3149 .cindex "inetd"
3150 The
3151 &%-bs%& option is also used to run Exim from &'inetd'&, as an alternative to
3152 using a listening daemon. Exim can distinguish the two cases by checking
3153 whether the standard input is a TCP/IP socket. When Exim is called from
3154 &'inetd'&, the source of the mail is assumed to be remote, and the comments
3155 above concerning senders and qualification do not apply. In this situation,
3156 Exim behaves in exactly the same way as it does when receiving a message via
3157 the listening daemon.
3159 .vitem &%-bt%&
3160 .oindex "&%-bt%&"
3161 .cindex "testing" "addresses"
3162 .cindex "address" "testing"
3163 This option runs Exim in address testing mode, in which each argument is taken
3164 as a recipient address to be tested for deliverability. The results are
3165 written to the standard output. If a test fails, and the caller is not an admin
3166 user, no details of the failure are output, because these might contain
3167 sensitive information such as usernames and passwords for database lookups.
3169 If no arguments are given, Exim runs in an interactive manner, prompting with a
3170 right angle bracket for addresses to be tested.
3172 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3173 &[readline()]& function, because it is running as &'root'& and there are
3174 security issues.
3176 Each address is handled as if it were the recipient address of a message
3177 (compare the &%-bv%& option). It is passed to the routers and the result is
3178 written to the standard output. However, any router that has
3179 &%no_address_test%& set is bypassed. This can make &%-bt%& easier to use for
3180 genuine routing tests if your first router passes everything to a scanner
3181 program.
3183 .cindex "return code" "for &%-bt%&"
3184 The return code is 2 if any address failed outright; it is 1 if no address
3185 failed outright but at least one could not be resolved for some reason. Return
3186 code 0 is given only when all addresses succeed.
3188 .cindex "duplicate addresses"
3189 &*Note*&: When actually delivering a message, Exim removes duplicate recipient
3190 addresses after routing is complete, so that only one delivery takes place.
3191 This does not happen when testing with &%-bt%&; the full results of routing are
3192 always shown.
3194 &*Warning*&: &%-bt%& can only do relatively simple testing. If any of the
3195 routers in the configuration makes any tests on the sender address of a
3196 message,
3197 .oindex "&%-f%&" "for address testing"
3198 you can use the &%-f%& option to set an appropriate sender when running
3199 &%-bt%& tests. Without it, the sender is assumed to be the calling user at the
3200 default qualifying domain. However, if you have set up (for example) routers
3201 whose behaviour depends on the contents of an incoming message, you cannot test
3202 those conditions using &%-bt%&. The &%-N%& option provides a possible way of
3203 doing such tests.
3205 .vitem &%-bV%&
3206 .oindex "&%-bV%&"
3207 .cindex "version number of Exim"
3208 This option causes Exim to write the current version number, compilation
3209 number, and compilation date of the &'exim'& binary to the standard output.
3210 It also lists the DBM library this is being used, the optional modules (such as
3211 specific lookup types), the drivers that are included in the binary, and the
3212 name of the run time configuration file that is in use.
3214 As part of its operation, &%-bV%& causes Exim to read and syntax check its
3215 configuration file. However, this is a static check only. It cannot check
3216 values that are to be expanded. For example, although a misspelt ACL verb is
3217 detected, an error in the verb's arguments is not. You cannot rely on &%-bV%&
3218 alone to discover (for example) all the typos in the configuration; some
3219 realistic testing is needed. The &%-bh%& and &%-N%& options provide more
3220 dynamic testing facilities.
3222 .vitem &%-bv%&
3223 .oindex "&%-bv%&"
3224 .cindex "verifying address" "using &%-bv%&"
3225 .cindex "address" "verification"
3226 This option runs Exim in address verification mode, in which each argument is
3227 taken as a recipient address to be verified by the routers. (This does
3228 not involve any verification callouts). During normal operation, verification
3229 happens mostly as a consequence processing a &%verify%& condition in an ACL
3230 (see chapter &<<CHAPACL>>&). If you want to test an entire ACL, possibly
3231 including callouts, see the &%-bh%& and &%-bhc%& options.
3233 If verification fails, and the caller is not an admin user, no details of the
3234 failure are output, because these might contain sensitive information such as
3235 usernames and passwords for database lookups.
3237 If no arguments are given, Exim runs in an interactive manner, prompting with a
3238 right angle bracket for addresses to be verified.
3240 Unlike the &%-be%& test option, you cannot arrange for Exim to use the
3241 &[readline()]& function, because it is running as &'exim'& and there are
3242 security issues.
3244 Verification differs from address testing (the &%-bt%& option) in that routers
3245 that have &%no_verify%& set are skipped, and if the address is accepted by a
3246 router that has &%fail_verify%& set, verification fails. The address is
3247 verified as a recipient if &%-bv%& is used; to test verification for a sender
3248 address, &%-bvs%& should be used.
3250 If the &%-v%& option is not set, the output consists of a single line for each
3251 address, stating whether it was verified or not, and giving a reason in the
3252 latter case. Without &%-v%&, generating more than one address by redirection
3253 causes verification to end successfully, without considering the generated
3254 addresses. However, if just one address is generated, processing continues,
3255 and the generated address must verify successfully for the overall verification
3256 to succeed.
3258 When &%-v%& is set, more details are given of how the address has been handled,
3259 and in the case of address redirection, all the generated addresses are also
3260 considered. Verification may succeed for some and fail for others.
3262 The
3263 .cindex "return code" "for &%-bv%&"
3264 return code is 2 if any address failed outright; it is 1 if no address
3265 failed outright but at least one could not be resolved for some reason. Return
3266 code 0 is given only when all addresses succeed.
3268 If any of the routers in the configuration makes any tests on the sender
3269 address of a message, you should use the &%-f%& option to set an appropriate
3270 sender when running &%-bv%& tests. Without it, the sender is assumed to be the
3271 calling user at the default qualifying domain.
3273 .vitem &%-bvs%&
3274 .oindex "&%-bvs%&"
3275 This option acts like &%-bv%&, but verifies the address as a sender rather
3276 than a recipient address. This affects any rewriting and qualification that
3277 might happen.
3279 .vitem &%-C%&&~<&'filelist'&>
3280 .oindex "&%-C%&"
3281 .cindex "configuration file" "alternate"
3282 .cindex "CONFIGURE_FILE"
3283 .cindex "alternate configuration file"
3284 This option causes Exim to find the run time configuration file from the given
3285 list instead of from the list specified by the CONFIGURE_FILE
3286 compile-time setting. Usually, the list will consist of just a single file
3287 name, but it can be a colon-separated list of names. In this case, the first
3288 file that exists is used. Failure to open an existing file stops Exim from
3289 proceeding any further along the list, and an error is generated.
3291 When this option is used by a caller other than root or the Exim user, and the
3292 list is different from the compiled-in list, Exim gives up its root privilege
3293 immediately, and runs with the real and effective uid and gid set to those of
3294 the caller. However, if ALT_CONFIG_ROOT_ONLY is defined in
3295 &_Local/Makefile_&, root privilege is retained for &%-C%& only if the caller of
3296 Exim is root.
3298 That is, the Exim user is no longer privileged in this regard. This build-time
3299 option is not set by default in the Exim source distribution tarbundle.
3300 However, if you are using a &"packaged"& version of Exim (source or binary),
3301 the packagers might have enabled it.
3303 Setting ALT_CONFIG_ROOT_ONLY locks out the possibility of testing a
3304 configuration using &%-C%& right through message reception and delivery, even
3305 if the caller is root. The reception works, but by that time, Exim is running
3306 as the Exim user, so when it re-executes to regain privilege for the delivery,
3307 the use of &%-C%& causes privilege to be lost. However, root can test reception
3308 and delivery using two separate commands (one to put a message on the queue,
3309 using &%-odq%&, and another to do the delivery, using &%-M%&).
3311 If ALT_CONFIG_PREFIX is defined &_in Local/Makefile_&, it specifies a
3312 prefix string with which any file named in a &%-C%& command line option
3313 must start. In addition, the file name must not contain the sequence &`/../`&.
3314 However, if the value of the &%-C%& option is identical to the value of
3315 CONFIGURE_FILE in &_Local/Makefile_&, Exim ignores &%-C%& and proceeds as
3316 usual. There is no default setting for ALT_CONFIG_PREFIX; when it is
3317 unset, any file name can be used with &%-C%&.
3319 ALT_CONFIG_PREFIX can be used to confine alternative configuration files
3320 to a directory to which only root has access. This prevents someone who has
3321 broken into the Exim account from running a privileged Exim with an arbitrary
3322 configuration file.
3324 The &%-C%& facility is useful for ensuring that configuration files are
3325 syntactically correct, but cannot be used for test deliveries, unless the
3326 caller is privileged, or unless it is an exotic configuration that does not
3327 require privilege. No check is made on the owner or group of the files
3328 specified by this option.
3330 .vitem &%-D%&<&'macro'&>=<&'value'&>
3331 .oindex "&%-D%&"
3332 .cindex "macro" "setting on command line"
3333 This option can be used to override macro definitions in the configuration file
3334 (see section &<<SECTmacrodefs>>&). However, like &%-C%&, if it is used by an
3335 unprivileged caller, it causes Exim to give up its root privilege.
3336 If DISABLE_D_OPTION is defined in &_Local/Makefile_&, the use of &%-D%& is
3337 completely disabled, and its use causes an immediate error exit.
3339 The entire option (including equals sign if present) must all be within one
3340 command line item. &%-D%& can be used to set the value of a macro to the empty
3341 string, in which case the equals sign is optional. These two commands are
3342 synonymous:
3343 .code
3344 exim -DABC ...
3345 exim -DABC= ...
3346 .endd
3347 To include spaces in a macro definition item, quotes must be used. If you use
3348 quotes, spaces are permitted around the macro name and the equals sign. For
3349 example:
3350 .code
3351 exim '-D ABC = something' ...
3352 .endd
3353 &%-D%& may be repeated up to 10 times on a command line.
3355 .vitem &%-d%&<&'debug&~options'&>
3356 .oindex "&%-d%&"
3357 .cindex "debugging" "list of selectors"
3358 .cindex "debugging" "&%-d%& option"
3359 This option causes debugging information to be written to the standard
3360 error stream. It is restricted to admin users because debugging output may show
3361 database queries that contain password information. Also, the details of users'
3362 filter files should be protected. If a non-admin user uses &%-d%&, Exim
3363 writes an error message to the standard error stream and exits with a non-zero
3364 return code.
3366 When &%-d%& is used, &%-v%& is assumed. If &%-d%& is given on its own, a lot of
3367 standard debugging data is output. This can be reduced, or increased to include
3368 some more rarely needed information, by directly following &%-d%& with a string
3369 made up of names preceded by plus or minus characters. These add or remove sets
3370 of debugging data, respectively. For example, &%-d+filter%& adds filter
3371 debugging, whereas &%-d-all+filter%& selects only filter debugging. Note that
3372 no spaces are allowed in the debug setting. The available debugging categories
3373 are:
3374 .display
3375 &`acl `& ACL interpretation
3376 &`auth `& authenticators
3377 &`deliver `& general delivery logic
3378 &`dns `& DNS lookups (see also resolver)
3379 &`dnsbl `& DNS black list (aka RBL) code
3380 &`exec `& arguments for &[execv()]& calls
3381 &`expand `& detailed debugging for string expansions
3382 &`filter `& filter handling
3383 &`hints_lookup `& hints data lookups
3384 &`host_lookup `& all types of name-to-IP address handling
3385 &`ident `& ident lookup
3386 &`interface `& lists of local interfaces
3387 &`lists `& matching things in lists
3388 &`load `& system load checks
3389 &`local_scan `& can be used by &[local_scan()]& (see chapter &&&
3390 &<<CHAPlocalscan>>&)
3391 &`lookup `& general lookup code and all lookups
3392 &`memory `& memory handling
3393 &`pid `& add pid to debug output lines
3394 &`process_info `& setting info for the process log
3395 &`queue_run `& queue runs
3396 &`receive `& general message reception logic
3397 &`resolver `& turn on the DNS resolver's debugging output
3398 &`retry `& retry handling
3399 &`rewrite `& address rewriting
3400 &`route `& address routing
3401 &`timestamp `& add timestamp to debug output lines
3402 &`tls `& TLS logic
3403 &`transport `& transports
3404 &`uid `& changes of uid/gid and looking up uid/gid
3405 &`verify `& address verification logic
3406 &`all `& almost all of the above (see below), and also &%-v%&
3407 .endd
3408 The &`all`& option excludes &`memory`& when used as &`+all`&, but includes it
3409 for &`-all`&. The reason for this is that &`+all`& is something that people
3410 tend to use when generating debug output for Exim maintainers. If &`+memory`&
3411 is included, an awful lot of output that is very rarely of interest is
3412 generated, so it now has to be explicitly requested. However, &`-all`& does
3413 turn everything off.
3415 .cindex "resolver, debugging output"
3416 .cindex "DNS resolver, debugging output"
3417 The &`resolver`& option produces output only if the DNS resolver was compiled
3418 with DEBUG enabled. This is not the case in some operating systems. Also,
3419 unfortunately, debugging output from the DNS resolver is written to stdout
3420 rather than stderr.
3422 The default (&%-d%& with no argument) omits &`expand`&, &`filter`&,
3423 &`interface`&, &`load`&, &`memory`&, &`pid`&, &`resolver`&, and &`timestamp`&.
3424 However, the &`pid`& selector is forced when debugging is turned on for a
3425 daemon, which then passes it on to any re-executed Exims. Exim also
3426 automatically adds the pid to debug lines when several remote deliveries are
3427 run in parallel.
3429 The &`timestamp`& selector causes the current time to be inserted at the start
3430 of all debug output lines. This can be useful when trying to track down delays
3431 in processing.
3433 If the &%debug_print%& option is set in any driver, it produces output whenever
3434 any debugging is selected, or if &%-v%& is used.
3436 .vitem &%-dd%&<&'debug&~options'&>
3437 .oindex "&%-dd%&"
3438 This option behaves exactly like &%-d%& except when used on a command that
3439 starts a daemon process. In that case, debugging is turned off for the
3440 subprocesses that the daemon creates. Thus, it is useful for monitoring the
3441 behaviour of the daemon without creating as much output as full debugging does.
3443 .vitem &%-dropcr%&
3444 .oindex "&%-dropcr%&"
3445 This is an obsolete option that is now a no-op. It used to affect the way Exim
3446 handled CR and LF characters in incoming messages. What happens now is
3447 described in section &<<SECTlineendings>>&.
3449 .vitem &%-E%&
3450 .oindex "&%-E%&"
3451 .cindex "bounce message" "generating"
3452 This option specifies that an incoming message is a locally-generated delivery
3453 failure report. It is used internally by Exim when handling delivery failures
3454 and is not intended for external use. Its only effect is to stop Exim
3455 generating certain messages to the postmaster, as otherwise message cascades
3456 could occur in some situations. As part of the same option, a message id may
3457 follow the characters &%-E%&. If it does, the log entry for the receipt of the
3458 new message contains the id, following &"R="&, as a cross-reference.
3460 .vitem &%-e%&&'x'&
3461 .oindex "&%-e%&&'x'&"
3462 There are a number of Sendmail options starting with &%-oe%& which seem to be
3463 called by various programs without the leading &%o%& in the option. For
3464 example, the &%vacation%& program uses &%-eq%&. Exim treats all options of the
3465 form &%-e%&&'x'& as synonymous with the corresponding &%-oe%&&'x'& options.
3467 .vitem &%-F%&&~<&'string'&>
3468 .oindex "&%-F%&"
3469 .cindex "sender" "name"
3470 .cindex "name" "of sender"
3471 This option sets the sender's full name for use when a locally-generated
3472 message is being accepted. In the absence of this option, the user's &'gecos'&
3473 entry from the password data is used. As users are generally permitted to alter
3474 their &'gecos'& entries, no security considerations are involved. White space
3475 between &%-F%& and the <&'string'&> is optional.
3477 .vitem &%-f%&&~<&'address'&>
3478 .oindex "&%-f%&"
3479 .cindex "sender" "address"
3480 .cindex "address" "sender"
3481 .cindex "trusted users"
3482 .cindex "envelope sender"
3483 .cindex "user" "trusted"
3484 This option sets the address of the envelope sender of a locally-generated
3485 message (also known as the return path). The option can normally be used only
3486 by a trusted user, but &%untrusted_set_sender%& can be set to allow untrusted
3487 users to use it.
3489 Processes running as root or the Exim user are always trusted. Other
3490 trusted users are defined by the &%trusted_users%& or &%trusted_groups%&
3491 options. In the absence of &%-f%&, or if the caller is not trusted, the sender
3492 of a local message is set to the caller's login name at the default qualify
3493 domain.
3495 There is one exception to the restriction on the use of &%-f%&: an empty sender
3496 can be specified by any user, trusted or not, to create a message that can
3497 never provoke a bounce. An empty sender can be specified either as an empty
3498 string, or as a pair of angle brackets with nothing between them, as in these
3499 examples of shell commands:
3500 .code
3501 exim -f '<>' user@domain
3502 exim -f "" user@domain
3503 .endd
3504 In addition, the use of &%-f%& is not restricted when testing a filter file
3505 with &%-bf%& or when testing or verifying addresses using the &%-bt%& or
3506 &%-bv%& options.
3508 Allowing untrusted users to change the sender address does not of itself make
3509 it possible to send anonymous mail. Exim still checks that the &'From:'& header
3510 refers to the local user, and if it does not, it adds a &'Sender:'& header,
3511 though this can be overridden by setting &%no_local_from_check%&.
3513 White
3514 .cindex "&""From""& line"
3515 space between &%-f%& and the <&'address'&> is optional (that is, they can be
3516 given as two arguments or one combined argument). The sender of a
3517 locally-generated message can also be set (when permitted) by an initial
3518 &"From&~"& line in the message &-- see the description of &%-bm%& above &-- but
3519 if &%-f%& is also present, it overrides &"From&~"&.
3521 .vitem &%-G%&
3522 .oindex "&%-G%&"
3523 .cindex "Sendmail compatibility" "&%-G%& option ignored"
3524 This is a Sendmail option which is ignored by Exim.
3526 .vitem &%-h%&&~<&'number'&>
3527 .oindex "&%-h%&"
3528 .cindex "Sendmail compatibility" "&%-h%& option ignored"
3529 This option is accepted for compatibility with Sendmail, but has no effect. (In
3530 Sendmail it overrides the &"hop count"& obtained by counting &'Received:'&
3531 headers.)
3533 .vitem &%-i%&
3534 .oindex "&%-i%&"
3535 .cindex "Solaris" "&'mail'& command"
3536 .cindex "dot" "in incoming non-SMTP message"
3537 This option, which has the same effect as &%-oi%&, specifies that a dot on a
3538 line by itself should not terminate an incoming, non-SMTP message. I can find
3539 no documentation for this option in Solaris 2.4 Sendmail, but the &'mailx'&
3540 command in Solaris 2.4 uses it. See also &%-ti%&.
3542 .vitem &%-M%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3543 .oindex "&%-M%&"
3544 .cindex "forcing delivery"
3545 .cindex "delivery" "forcing attempt"
3546 .cindex "frozen messages" "forcing delivery"
3547 This option requests Exim to run a delivery attempt on each message in turn. If
3548 any of the messages are frozen, they are automatically thawed before the
3549 delivery attempt. The settings of &%queue_domains%&, &%queue_smtp_domains%&,
3550 and &%hold_domains%& are ignored.
3552 Retry
3553 .cindex "hints database" "overriding retry hints"
3554 hints for any of the addresses are overridden &-- Exim tries to deliver even if
3555 the normal retry time has not yet been reached. This option requires the caller
3556 to be an admin user. However, there is an option called &%prod_requires_admin%&
3557 which can be set false to relax this restriction (and also the same requirement
3558 for the &%-q%&, &%-R%&, and &%-S%& options).
3560 The deliveries happen synchronously, that is, the original Exim process does
3561 not terminate until all the delivery attempts have finished. No output is
3562 produced unless there is a serious error. If you want to see what is happening,
3563 use the &%-v%& option as well, or inspect Exim's main log.
3565 .vitem &%-Mar%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
3566 .oindex "&%-Mar%&"
3567 .cindex "message" "adding recipients"
3568 .cindex "recipient" "adding"
3569 This option requests Exim to add the addresses to the list of recipients of the
3570 message (&"ar"& for &"add recipients"&). The first argument must be a message
3571 id, and the remaining ones must be email addresses. However, if the message is
3572 active (in the middle of a delivery attempt), it is not altered. This option
3573 can be used only by an admin user.
3575 .vitem "&%-MC%&&~<&'transport'&>&~<&'hostname'&>&~<&'sequence&~number'&>&&&
3576 &~<&'message&~id'&>"
3577 .oindex "&%-MC%&"
3578 .cindex "SMTP" "passed connection"
3579 .cindex "SMTP" "multiple deliveries"
3580 .cindex "multiple SMTP deliveries"
3581 This option is not intended for use by external callers. It is used internally
3582 by Exim to invoke another instance of itself to deliver a waiting message using
3583 an existing SMTP connection, which is passed as the standard input. Details are
3584 given in chapter &<<CHAPSMTP>>&. This must be the final option, and the caller
3585 must be root or the Exim user in order to use it.
3587 .vitem &%-MCA%&
3588 .oindex "&%-MCA%&"
3589 This option is not intended for use by external callers. It is used internally
3590 by Exim in conjunction with the &%-MC%& option. It signifies that the
3591 connection to the remote host has been authenticated.
3593 .vitem &%-MCP%&
3594 .oindex "&%-MCP%&"
3595 This option is not intended for use by external callers. It is used internally
3596 by Exim in conjunction with the &%-MC%& option. It signifies that the server to
3597 which Exim is connected supports pipelining.
3599 .vitem &%-MCQ%&&~<&'process&~id'&>&~<&'pipe&~fd'&>
3600 .oindex "&%-MCQ%&"
3601 This option is not intended for use by external callers. It is used internally
3602 by Exim in conjunction with the &%-MC%& option when the original delivery was
3603 started by a queue runner. It passes on the process id of the queue runner,
3604 together with the file descriptor number of an open pipe. Closure of the pipe
3605 signals the final completion of the sequence of processes that are passing
3606 messages through the same SMTP connection.
3608 .vitem &%-MCS%&
3609 .oindex "&%-MCS%&"
3610 This option is not intended for use by external callers. It is used internally
3611 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3612 SMTP SIZE option should be used on messages delivered down the existing
3613 connection.
3615 .vitem &%-MCT%&
3616 .oindex "&%-MCT%&"
3617 This option is not intended for use by external callers. It is used internally
3618 by Exim in conjunction with the &%-MC%& option, and passes on the fact that the
3619 host to which Exim is connected supports TLS encryption.
3621 .vitem &%-Mc%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3622 .oindex "&%-Mc%&"
3623 .cindex "hints database" "not overridden by &%-Mc%&"
3624 .cindex "delivery" "manually started &-- not forced"
3625 This option requests Exim to run a delivery attempt on each message in turn,
3626 but unlike the &%-M%& option, it does check for retry hints, and respects any
3627 that are found. This option is not very useful to external callers. It is
3628 provided mainly for internal use by Exim when it needs to re-invoke itself in
3629 order to regain root privilege for a delivery (see chapter &<<CHAPsecurity>>&).
3630 However, &%-Mc%& can be useful when testing, in order to run a delivery that
3631 respects retry times and other options such as &%hold_domains%& that are
3632 overridden when &%-M%& is used. Such a delivery does not count as a queue run.
3633 If you want to run a specific delivery as if in a queue run, you should use
3634 &%-q%& with a message id argument. A distinction between queue run deliveries
3635 and other deliveries is made in one or two places.
3637 .vitem &%-Mes%&&~<&'message&~id'&>&~<&'address'&>
3638 .oindex "&%-Mes%&"
3639 .cindex "message" "changing sender"
3640 .cindex "sender" "changing"
3641 This option requests Exim to change the sender address in the message to the
3642 given address, which must be a fully qualified address or &"<>"& (&"es"& for
3643 &"edit sender"&). There must be exactly two arguments. The first argument must
3644 be a message id, and the second one an email address. However, if the message
3645 is active (in the middle of a delivery attempt), its status is not altered.
3646 This option can be used only by an admin user.
3648 .vitem &%-Mf%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3649 .oindex "&%-Mf%&"
3650 .cindex "freezing messages"
3651 .cindex "message" "manually freezing"
3652 This option requests Exim to mark each listed message as &"frozen"&. This
3653 prevents any delivery attempts taking place until the message is &"thawed"&,
3654 either manually or as a result of the &%auto_thaw%& configuration option.
3655 However, if any of the messages are active (in the middle of a delivery
3656 attempt), their status is not altered. This option can be used only by an admin
3657 user.
3659 .vitem &%-Mg%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3660 .oindex "&%-Mg%&"
3661 .cindex "giving up on messages"
3662 .cindex "message" "abandoning delivery attempts"
3663 .cindex "delivery" "abandoning further attempts"
3664 This option requests Exim to give up trying to deliver the listed messages,
3665 including any that are frozen. However, if any of the messages are active,
3666 their status is not altered. For non-bounce messages, a delivery error message
3667 is sent to the sender, containing the text &"cancelled by administrator"&.
3668 Bounce messages are just discarded. This option can be used only by an admin
3669 user.
3671 .vitem &%-Mmad%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3672 .oindex "&%-Mmad%&"
3673 .cindex "delivery" "cancelling all"
3674 This option requests Exim to mark all the recipient addresses in the messages
3675 as already delivered (&"mad"& for &"mark all delivered"&). However, if any
3676 message is active (in the middle of a delivery attempt), its status is not
3677 altered. This option can be used only by an admin user.
3679 .vitem &%-Mmd%&&~<&'message&~id'&>&~<&'address'&>&~<&'address'&>&~...
3680 .oindex "&%-Mmd%&"
3681 .cindex "delivery" "cancelling by address"
3682 .cindex "recipient" "removing"
3683 .cindex "removing recipients"
3684 This option requests Exim to mark the given addresses as already delivered
3685 (&"md"& for &"mark delivered"&). The first argument must be a message id, and
3686 the remaining ones must be email addresses. These are matched to recipient
3687 addresses in the message in a case-sensitive manner. If the message is active
3688 (in the middle of a delivery attempt), its status is not altered. This option
3689 can be used only by an admin user.
3691 .vitem &%-Mrm%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3692 .oindex "&%-Mrm%&"
3693 .cindex "removing messages"
3694 .cindex "abandoning mail"
3695 .cindex "message" "manually discarding"
3696 This option requests Exim to remove the given messages from the queue. No
3697 bounce messages are sent; each message is simply forgotten. However, if any of
3698 the messages are active, their status is not altered. This option can be used
3699 only by an admin user or by the user who originally caused the message to be
3700 placed on the queue.
3702 .vitem &%-Mset%&&~<&'message&~id'&>
3703 .oindex "&%-Mset%&
3704 .cindex "testing" "string expansion"
3705 .cindex "expansion" "testing"
3706 This option is useful only in conjunction with &%-be%& (that is, when testing
3707 string expansions). Exim loads the given message from its spool before doing
3708 the test expansions, thus setting message-specific variables such as
3709 &$message_size$& and the header variables. The &$recipients$& variable is made
3710 available. This feature is provided to make it easier to test expansions that
3711 make use of these variables. However, this option can be used only by an admin
3712 user. See also &%-bem%&.
3714 .vitem &%-Mt%&&~<&'message&~id'&>&~<&'message&~id'&>&~...
3715 .oindex "&%-Mt%&"
3716 .cindex "thawing messages"
3717 .cindex "unfreezing messages"
3718 .cindex "frozen messages" "thawing"
3719 .cindex "message" "thawing frozen"
3720 This option requests Exim to &"thaw"& any of the listed messages that are
3721 &"frozen"&, so that delivery attempts can resume. However, if any of the
3722 messages are active, their status is not altered. This option can be used only
3723 by an admin user.
3725 .vitem &%-Mvb%&&~<&'message&~id'&>
3726 .oindex "&%-Mvb%&"
3727 .cindex "listing" "message body"
3728 .cindex "message" "listing body of"
3729 This option causes the contents of the message body (-D) spool file to be
3730 written to the standard output. This option can be used only by an admin user.
3732 .vitem &%-Mvc%&&~<&'message&~id'&>
3733 .oindex "&%-Mvc%&"
3734 .cindex "message" "listing in RFC 2822 format"
3735 .cindex "listing" "message in RFC 2922 format"
3736 This option causes a copy of the complete message (header lines plus body) to
3737 be written to the standard output in RFC 2822 format. This option can be used
3738 only by an admin user.
3740 .vitem &%-Mvh%&&~<&'message&~id'&>
3741 .oindex "&%-Mvh%&"
3742 .cindex "listing" "message headers"
3743 .cindex "header lines" "listing"
3744 .cindex "message" "listing header lines"
3745 This option causes the contents of the message headers (-H) spool file to be
3746 written to the standard output. This option can be used only by an admin user.
3748 .vitem &%-Mvl%&&~<&'message&~id'&>
3749 .oindex "&%-Mvl%&"
3750 .cindex "listing" "message log"
3751 .cindex "message" "listing message log"
3752 This option causes the contents of the message log spool file to be written to
3753 the standard output. This option can be used only by an admin user.
3755 .vitem &%-m%&
3756 .oindex "&%-m%&"
3757 This is apparently a synonym for &%-om%& that is accepted by Sendmail, so Exim
3758 treats it that way too.
3760 .vitem &%-N%&
3761 .oindex "&%-N%&"
3762 .cindex "debugging" "&%-N%& option"
3763 .cindex "debugging" "suppressing delivery"
3764 This is a debugging option that inhibits delivery of a message at the transport
3765 level. It implies &%-v%&. Exim goes through many of the motions of delivery &--
3766 it just doesn't actually transport the message, but instead behaves as if it
3767 had successfully done so. However, it does not make any updates to the retry
3768 database, and the log entries for deliveries are flagged with &"*>"& rather
3769 than &"=>"&.
3771 Because &%-N%& discards any message to which it applies, only root or the Exim
3772 user are allowed to use it with &%-bd%&, &%-q%&, &%-R%& or &%-M%&. In other
3773 words, an ordinary user can use it only when supplying an incoming message to
3774 which it will apply. Although transportation never fails when &%-N%& is set, an
3775 address may be deferred because of a configuration problem on a transport, or a
3776 routing problem. Once &%-N%& has been used for a delivery attempt, it sticks to
3777 the message, and applies to any subsequent delivery attempts that may happen
3778 for that message.
3780 .vitem &%-n%&
3781 .oindex "&%-n%&"
3782 .cindex "Sendmail compatibility" "&%-n%& option ignored"
3783 This option is interpreted by Sendmail to mean &"no aliasing"&. It is ignored
3784 by Exim.
3786 .vitem &%-O%&&~<&'data'&>
3787 .oindex "&%-O%&"
3788 This option is interpreted by Sendmail to mean &`set option`&. It is ignored by
3789 Exim.
3791 .vitem &%-oA%&&~<&'file&~name'&>
3792 .oindex "&%-oA%&"
3793 .cindex "Sendmail compatibility" "&%-oA%& option"
3794 This option is used by Sendmail in conjunction with &%-bi%& to specify an
3795 alternative alias file name. Exim handles &%-bi%& differently; see the
3796 description above.
3798 .vitem &%-oB%&&~<&'n'&>
3799 .oindex "&%-oB%&"
3800 .cindex "SMTP" "passed connection"
3801 .cindex "SMTP" "multiple deliveries"
3802 .cindex "multiple SMTP deliveries"
3803 This is a debugging option which limits the maximum number of messages that can
3804 be delivered down one SMTP connection, overriding the value set in any &(smtp)&
3805 transport. If <&'n'&> is omitted, the limit is set to 1.
3807 .vitem &%-odb%&
3808 .oindex "&%-odb%&"
3809 .cindex "background delivery"
3810 .cindex "delivery" "in the background"
3811 This option applies to all modes in which Exim accepts incoming messages,
3812 including the listening daemon. It requests &"background"& delivery of such
3813 messages, which means that the accepting process automatically starts a
3814 delivery process for each message received, but does not wait for the delivery
3815 processes to finish.
3817 When all the messages have been received, the reception process exits,
3818 leaving the delivery processes to finish in their own time. The standard output
3819 and error streams are closed at the start of each delivery process.
3820 This is the default action if none of the &%-od%& options are present.
3822 If one of the queueing options in the configuration file
3823 (&%queue_only%& or &%queue_only_file%&, for example) is in effect, &%-odb%&
3824 overrides it if &%queue_only_override%& is set true, which is the default
3825 setting. If &%queue_only_override%& is set false, &%-odb%& has no effect.
3827 .vitem &%-odf%&
3828 .oindex "&%-odf%&"
3829 .cindex "foreground delivery"
3830 .cindex "delivery" "in the foreground"
3831 This option requests &"foreground"& (synchronous) delivery when Exim has
3832 accepted a locally-generated message. (For the daemon it is exactly the same as
3833 &%-odb%&.) A delivery process is automatically started to deliver the message,
3834 and Exim waits for it to complete before proceeding.
3836 The original Exim reception process does not finish until the delivery
3837 process for the final message has ended. The standard error stream is left open
3838 during deliveries.
3840 However, like &%-odb%&, this option has no effect if &%queue_only_override%& is
3841 false and one of the queueing options in the configuration file is in effect.
3843 If there is a temporary delivery error during foreground delivery, the
3844 message is left on the queue for later delivery, and the original reception
3845 process exits. See chapter &<<CHAPnonqueueing>>& for a way of setting up a
3846 restricted configuration that never queues messages.
3849 .vitem &%-odi%&
3850 .oindex "&%-odi%&"
3851 This option is synonymous with &%-odf%&. It is provided for compatibility with
3852 Sendmail.
3854 .vitem &%-odq%&
3855 .oindex "&%-odq%&"
3856 .cindex "non-immediate delivery"
3857 .cindex "delivery" "suppressing immediate"
3858 .cindex "queueing incoming messages"
3859 This option applies to all modes in which Exim accepts incoming messages,
3860 including the listening daemon. It specifies that the accepting process should
3861 not automatically start a delivery process for each message received. Messages
3862 are placed on the queue, and remain there until a subsequent queue runner
3863 process encounters them. There are several configuration options (such as
3864 &%queue_only%&) that can be used to queue incoming messages under certain
3865 conditions. This option overrides all of them and also &%-odqs%&. It always
3866 forces queueing.
3868 .vitem &%-odqs%&
3869 .oindex "&%-odqs%&"
3870 .cindex "SMTP" "delaying delivery"
3871 This option is a hybrid between &%-odb%&/&%-odi%& and &%-odq%&.
3872 However, like &%-odb%& and &%-odi%&, this option has no effect if
3873 &%queue_only_override%& is false and one of the queueing options in the
3874 configuration file is in effect.
3876 When &%-odqs%& does operate, a delivery process is started for each incoming
3877 message, in the background by default, but in the foreground if &%-odi%& is
3878 also present. The recipient addresses are routed, and local deliveries are done
3879 in the normal way. However, if any SMTP deliveries are required, they are not
3880 done at this time, so the message remains on the queue until a subsequent queue
3881 runner process encounters it. Because routing was done, Exim knows which
3882 messages are waiting for which hosts, and so a number of messages for the same
3883 host can be sent in a single SMTP connection. The &%queue_smtp_domains%&
3884 configuration option has the same effect for specific domains. See also the
3885 &%-qq%& option.
3887 .vitem &%-oee%&
3888 .oindex "&%-oee%&"
3889 .cindex "error" "reporting"
3890 If an error is detected while a non-SMTP message is being received (for
3891 example, a malformed address), the error is reported to the sender in a mail
3892 message.
3894 .cindex "return code" "for &%-oee%&"
3895 Provided
3896 this error message is successfully sent, the Exim receiving process
3897 exits with a return code of zero. If not, the return code is 2 if the problem
3898 is that the original message has no recipients, or 1 any other error. This is
3899 the default &%-oe%&&'x'& option if Exim is called as &'rmail'&.
3901 .vitem &%-oem%&
3902 .oindex "&%-oem%&"
3903 .cindex "error" "reporting"
3904 .cindex "return code" "for &%-oem%&"
3905 This is the same as &%-oee%&, except that Exim always exits with a non-zero
3906 return code, whether or not the error message was successfully sent.
3907 This is the default &%-oe%&&'x'& option, unless Exim is called as &'rmail'&.
3909 .vitem &%-oep%&
3910 .oindex "&%-oep%&"
3911 .cindex "error" "reporting"
3912 If an error is detected while a non-SMTP message is being received, the
3913 error is reported by writing a message to the standard error file (stderr).
3914 .cindex "return code" "for &%-oep%&"
3915 The return code is 1 for all errors.
3917 .vitem &%-oeq%&
3918 .oindex "&%-oeq%&"
3919 .cindex "error" "reporting"
3920 This option is supported for compatibility with Sendmail, but has the same
3921 effect as &%-oep%&.
3923 .vitem &%-oew%&
3924 .oindex "&%-oew%&"
3925 .cindex "error" "reporting"
3926 This option is supported for compatibility with Sendmail, but has the same
3927 effect as &%-oem%&.
3929 .vitem &%-oi%&
3930 .oindex "&%-oi%&"
3931 .cindex "dot" "in incoming non-SMTP message"
3932 This option, which has the same effect as &%-i%&, specifies that a dot on a
3933 line by itself should not terminate an incoming, non-SMTP message. Otherwise, a
3934 single dot does terminate, though Exim does no special processing for other
3935 lines that start with a dot. This option is set by default if Exim is called as
3936 &'rmail'&. See also &%-ti%&.
3938 .vitem &%-oitrue%&
3939 .oindex "&%-oitrue%&"
3940 This option is treated as synonymous with &%-oi%&.
3942 .vitem &%-oMa%&&~<&'host&~address'&>
3943 .oindex "&%-oMa%&"
3944 .cindex "sender" "host address, specifying for local message"
3945 A number of options starting with &%-oM%& can be used to set values associated
3946 with remote hosts on locally-submitted messages (that is, messages not received
3947 over TCP/IP). These options can be used by any caller in conjunction with the
3948 &%-bh%&, &%-be%&, &%-bf%&, &%-bF%&, &%-bt%&, or &%-bv%& testing options. In
3949 other circumstances, they are ignored unless the caller is trusted.
3951 The &%-oMa%& option sets the sender host address. This may include a port
3952 number at the end, after a full stop (period). For example:
3953 .code
3954 exim -bs -oMa
3955 .endd
3956 An alternative syntax is to enclose the IP address in square brackets,
3957 followed by a colon and the port number:
3958 .code
3959 exim -bs -oMa []:1234
3960 .endd
3961 The IP address is placed in the &$sender_host_address$& variable, and the
3962 port, if present, in &$sender_host_port$&. If both &%-oMa%& and &%-bh%&
3963 are present on the command line, the sender host IP address is taken from
3964 whichever one is last.
3966 .vitem &%-oMaa%&&~<&'name'&>
3967 .oindex "&%-oMaa%&"
3968 .cindex "authentication" "name, specifying for local message"
3969 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMaa%&
3970 option sets the value of &$sender_host_authenticated$& (the authenticator
3971 name). See chapter &<<CHAPSMTPAUTH>>& for a discussion of SMTP authentication.
3972 This option can be used with &%-bh%& and &%-bs%& to set up an
3973 authenticated SMTP session without actually using the SMTP AUTH command.
3975 .vitem &%-oMai%&&~<&'string'&>
3976 .oindex "&%-oMai%&"
3977 .cindex "authentication" "id, specifying for local message"
3978 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMai%&
3979 option sets the value of &$authenticated_id$& (the id that was authenticated).
3980 This overrides the default value (the caller's login id, except with &%-bh%&,
3981 where there is no default) for messages from local sources. See chapter
3982 &<<CHAPSMTPAUTH>>& for a discussion of authenticated ids.
3984 .vitem &%-oMas%&&~<&'address'&>
3985 .oindex "&%-oMas%&"
3986 .cindex "authentication" "sender, specifying for local message"
3987 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMas%&
3988 option sets the authenticated sender value in &$authenticated_sender$&. It
3989 overrides the sender address that is created from the caller's login id for
3990 messages from local sources, except when &%-bh%& is used, when there is no
3991 default. For both &%-bh%& and &%-bs%&, an authenticated sender that is
3992 specified on a MAIL command overrides this value. See chapter
3993 &<<CHAPSMTPAUTH>>& for a discussion of authenticated senders.
3995 .vitem &%-oMi%&&~<&'interface&~address'&>
3996 .oindex "&%-oMi%&"
3997 .cindex "interface" "address, specifying for local message"
3998 See &%-oMa%& above for general remarks about the &%-oM%& options. The &%-oMi%&
3999 option sets the IP interface address value. A port number may be included,
4000 usin