Initial work removing PCRE from dist. Documentation needs to be updated. Related...
[exim.git] / doc / doc-docbook / spec.xfpt
CommitLineData
207c78ae 1. $Cambridge: exim/doc/doc-docbook/spec.xfpt,v 1.27 2007/12/01 15:53:55 nm4 Exp $
9b371988
PH
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.
595028e4
PH
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.
9b371988
PH
12. /////////////////////////////////////////////////////////////////////////////
13
14.include stdflags
15.include stdmacs
9b371988
PH
16
17. /////////////////////////////////////////////////////////////////////////////
33393583 18. This outputs the standard DocBook boilerplate.
9b371988
PH
19. /////////////////////////////////////////////////////////////////////////////
20
33393583 21.docbook
3cb1b51e
PH
22
23. /////////////////////////////////////////////////////////////////////////////
24. These lines are processing instructions for the Simple DocBook Processor that
f89d2485
PH
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.
3cb1b51e
PH
28. /////////////////////////////////////////////////////////////////////////////
29
30.literal xml
31<?sdop
f89d2485
PH
32 foot_right_recto="&chaptertitle; (&chapternumber;)"
33 foot_right_verso="&chaptertitle; (&chapternumber;)"
3cb1b51e 34 toc_chapter_blanks="yes,yes"
595028e4 35 table_warn_overflow="overprint"
3cb1b51e
PH
36?>
37.literal off
9b371988 38
33393583
PH
39. /////////////////////////////////////////////////////////////////////////////
40. This generate the outermost <book> element that wraps then entire document.
41. /////////////////////////////////////////////////////////////////////////////
42
43.book
44
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. /////////////////////////////////////////////////////////////////////////////
49
207c78ae
NM
50.set previousversion "4.68"
51.set version "4.69"
f89d2485 52
33393583 53.set ACL "access control lists (ACLs)"
f89d2485 54.set I "&nbsp;&nbsp;&nbsp;&nbsp;"
33393583 55
9b371988
PH
56
57. /////////////////////////////////////////////////////////////////////////////
58. Additional xfpt markup used by this document, over and above the default
59. provided in the xfpt library.
60. /////////////////////////////////////////////////////////////////////////////
61
62. --- Override the &$ flag to automatically insert a $ with the variable name
63
64.flag &$ $& "<varname>$" "</varname>"
65
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.
68
69.flag &!! "</emphasis>&dagger;<emphasis>"
70.flag &!? "</emphasis>&Dagger;<emphasis>"
71
72. --- A macro for an Exim option definition heading, generating a one-line
0a4e3112
PH
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.
9b371988
PH
76
77.macro option
0a4e3112
PH
78.arg 5
79.oindex "&%$5%&"
80.endarg
81.arg -5
3cb1b51e 82.oindex "&%$1%&"
0a4e3112 83.endarg
f89d2485 84.itable all 0 0 4 8* left 6* center 6* center 6* right
9b371988
PH
85.row "&%$1%&" "Use: &'$2'&" "Type: &'$3'&" "Default: &'$4'&"
86.endtable
87.endmacro
88
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.
92
db9452a9 93.macro table2 196pt 254pt
9b371988
PH
94.itable none 0 0 2 $1 left $2 left
95.endmacro
96
f89d2485
PH
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.
100
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
114
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.
9b371988
PH
119
120.macro cindex
121&<indexterm role="concept">&
122&<primary>&$1&</primary>&
123.arg 2
124&<secondary>&$2&</secondary>&
125.endarg
126&</indexterm>&
127.endmacro
128
4f578862
PH
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
137
138.macro ecindex
139&<indexterm role="concept" startref="$1" class="endofrange"/>&
140.endmacro
141
9b371988
PH
142.macro oindex
143&<indexterm role="option">&
144&<primary>&$1&</primary>&
145.arg 2
146&<secondary>&$2&</secondary>&
147.endarg
148&</indexterm>&
149.endmacro
150
f89d2485
PH
151.macro vindex
152&<indexterm role="variable">&
153&<primary>&$1&</primary>&
154.arg 2
155&<secondary>&$2&</secondary>&
156.endarg
157&</indexterm>&
158.endmacro
159
9b371988 160.macro index
f89d2485 161.echo "** Don't use .index; use .cindex or .oindex or .vindex"
9b371988
PH
162.endmacro
163. ////////////////////////////////////////////////////////////////////////////
164
165
166. ////////////////////////////////////////////////////////////////////////////
167. The <bookinfo> element is removed from the XML before processing for Ascii
168. output formats.
169. ////////////////////////////////////////////////////////////////////////////
170
171.literal xml
172<bookinfo>
173<title>Specification of the Exim Mail Transfer Agent</title>
174<titleabbrev>The Exim MTA</titleabbrev>
595028e4 175<date>23 August 2007</date>
9b371988
PH
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>
595028e4
PH
181 <revnumber>4.68</revnumber>
182 <date>23 August 2007</date>
9b371988
PH
183 <authorinitials>PH</authorinitials>
184</revision></revhistory>
ad268134 185<copyright><year>2007</year><holder>University of Cambridge</holder></copyright>
9b371988
PH
186</bookinfo>
187.literal off
188
189
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. /////////////////////////////////////////////////////////////////////////////
195
f89d2485 196.chapter "Introduction" "CHID1"
9b371988
PH
197.literal xml
198
f89d2485 199<indexterm role="variable">
168e428f
PH
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">
068aaea8
PH
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">
168e428f
PH
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>
595028e4 260 <seealso><emphasis>limit</emphasis></seealso>
168e428f
PH
261</indexterm>
262<indexterm role="concept">
068aaea8
PH
263 <primary>monitor</primary>
264 <see><emphasis>Exim monitor</emphasis></see>
265</indexterm>
266<indexterm role="concept">
168e428f
PH
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>
9b371988
PH
319
320.literal off
168e428f
PH
321
322
9b371988
PH
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. /////////////////////////////////////////////////////////////////////////////
168e428f
PH
328
329Exim is a mail transfer agent (MTA) for hosts that are running Unix or
330Unix-like operating systems. It was designed on the assumption that it would be
331run on hosts that are permanently connected to the Internet. However, it can be
332used on intermittently connected hosts with suitable configuration adjustments.
333
334Configuration files currently exist for the following operating systems: AIX,
068aaea8
PH
335BSD/OS (aka BSDI), Darwin (Mac OS X), DGUX, Dragonfly, FreeBSD, GNU/Hurd,
336GNU/Linux, HI-OSF (Hitachi), HI-UX, HP-UX, IRIX, MIPS RISCOS, NetBSD, OpenBSD,
337OpenUNIX, QNX, SCO, SCO SVR4.2 (aka UNIX-SV), Solaris (aka SunOS5), SunOS4,
338Tru64-Unix (formerly Digital UNIX, formerly DEC-OSF1), Ultrix, and Unixware.
339Some of these operating systems are no longer current and cannot easily be
340tested, so the configuration files may no longer work in practice.
168e428f
PH
341
342There are also configuration files for compiling Exim in the Cygwin environment
343that can be installed on systems running Windows. However, this document does
344not contain any information about running Exim in the Cygwin environment.
345
346The terms and conditions for the use and distribution of Exim are contained in
9b371988
PH
347the file &_NOTICE_&. Exim is distributed under the terms of the GNU General
348Public Licence, a copy of which may be found in the file &_LICENCE_&.
168e428f
PH
349
350The use, supply or promotion of Exim for the purpose of sending bulk,
351unsolicited electronic mail is incompatible with the basic aims of the program,
352which revolve around the free provision of a service that enhances the quality
353of personal communications. The author of Exim regards indiscriminate
354mass-mailing as an antisocial, irresponsible abuse of the Internet.
355
356Exim owes a great deal to Smail 3 and its author, Ron Karr. Without the
357experience of running and working on the Smail 3 code, I could never have
358contemplated starting to write a new MTA. Many of the ideas and user interfaces
359were originally taken from Smail 3, though the actual code of Exim is entirely
360new, and has developed far beyond the initial concept.
361
362Many people, both in Cambridge and around the world, have contributed to the
363development and the testing of Exim, and to porting it to various operating
364systems. I am grateful to them all. The distribution now contains a file called
9b371988 365&_ACKNOWLEDGMENTS_&, in which I have started recording the names of
168e428f
PH
366contributors.
367
368
f89d2485 369.section "Exim documentation" "SECID1"
9b371988
PH
370.new
371.cindex "documentation"
372This edition of the Exim specification applies to version &version; of Exim.
373Substantive changes from the &previousversion; edition are marked in some
168e428f
PH
374renditions of the document; this paragraph is so marked if the rendition is
375capable of showing a change indicator.
9b371988 376.wen
168e428f
PH
377
378This document is very much a reference manual; it is not a tutorial. The reader
379is expected to have some familiarity with the SMTP mail transfer protocol and
380with general Unix system administration. Although there are some discussions
381and examples in places, the information is mostly organized in a way that makes
382it easy to look up, rather than in a natural order for sequential reading.
383Furthermore, the manual aims to cover every aspect of Exim in detail, including
384a number of rarely-used, special-purpose features that are unlikely to be of
385very wide interest.
386
9b371988
PH
387.cindex "books about Exim"
388An &"easier"& discussion of Exim which provides more in-depth explanatory,
389introductory, and tutorial material can be found in a book entitled &'The Exim
595028e4 390SMTP Mail Server'& (second edition, 2007), published by UIT Cambridge
9b371988 391(&url(http://www.uit.co.uk/exim-book/)).
168e428f
PH
392
393This book also contains a chapter that gives a general introduction to SMTP and
394Internet mail. Inevitably, however, the book is unlikely to be fully up-to-date
395with the latest release of Exim. (Note that the earlier book about Exim,
396published by O'Reilly, covers Exim 3, and many things have changed in Exim 4.)
397
9b371988 398.cindex "Debian" "information sources"
068aaea8
PH
399If you are using a Debian distribution of Exim, you will find information about
400Debian-specific features in the file
f89d2485 401&_/usr/share/doc/exim4-base/README.Debian_&.
9b371988 402The command &(man update-exim.conf)& is another source of Debian-specific
068aaea8
PH
403information.
404
9b371988
PH
405.cindex "&_doc/NewStuff_&"
406.cindex "&_doc/ChangeLog_&"
407.cindex "change log"
168e428f
PH
408As the program develops, there may be features in newer versions that have not
409yet made it into this document, which is updated only when the most significant
410digit of the fractional part of the version number changes. Specifications of
411new features that are not yet in this manual are placed in the file
9b371988 412&_doc/NewStuff_& in the Exim distribution.
168e428f 413
9b371988 414Some features may be classified as &"experimental"&. These may change
168e428f
PH
415incompatibly while they are developing, or even be withdrawn. For this reason,
416they are not documented in this manual. Information about experimental features
9b371988 417can be found in the file &_doc/experimental.txt_&.
168e428f
PH
418
419All changes to the program (whether new features, bug fixes, or other kinds of
9b371988 420change) are noted briefly in the file called &_doc/ChangeLog_&.
168e428f 421
9b371988
PH
422.cindex "&_doc/spec.txt_&"
423This specification itself is available as an ASCII file in &_doc/spec.txt_& so
424that it can easily be searched with a text editor. Other files in the &_doc_&
168e428f
PH
425directory are:
426
9b371988
PH
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
168e428f
PH
438
439The main specification and the specification of the filtering language are also
440available in other formats (HTML, PostScript, PDF, and Texinfo). Section
9b371988 441&<<SECTavail>>& below tells you how to get hold of these.
168e428f
PH
442
443
444
f89d2485 445.section "FTP and web sites" "SECID2"
9b371988
PH
446.cindex "web site"
447.cindex "FTP site"
068aaea8 448The primary site for Exim source distributions is currently the University of
9b371988
PH
449Cambridge's FTP site, whose contents are described in &'Where to find the Exim
450distribution'& 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
453Squared, formerly Planet Online Ltd, whose support I gratefully acknowledge.
454
455.cindex "wiki"
456.cindex "FAQ"
168e428f 457As well as Exim distribution tar files, the Exim web site contains a number of
f89d2485 458differently formatted versions of the documentation. A recent addition to the
595028e4 459online information is the Exim wiki &new("(&url(http://wiki.exim.org))"),
f89d2485
PH
460which contains what used to be a separate FAQ, as well as various other
461examples, tips, and know-how that have been contributed by Exim users.
462
463.cindex Bugzilla
595028e4 464An Exim Bugzilla exists at &new("&url(http://bugs.exim.org)"). You can use
f89d2485
PH
465this to report bugs, and also to add items to the wish list. Please search
466first to check that you are not duplicating a previous entry.
168e428f
PH
467
468
469
f89d2485 470.section "Mailing lists" "SECID3"
9b371988 471.cindex "mailing lists" "for Exim users"
f89d2485 472The following Exim mailing lists exist:
168e428f 473
9b371988 474.table2 140pt
f89d2485
PH
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"
9b371988 479.endtable
168e428f
PH
480
481You can subscribe to these lists, change your existing subscriptions, and view
9b371988
PH
482or search the archives via the mailing lists link on the Exim home page.
483.cindex "Debian" "mailing list for"
4f578862 484If you are using a Debian distribution of Exim, you may wish to subscribe to
db9452a9
PH
485the Debian-specific mailing list &'pkg-exim4-users@lists.alioth.debian.org'&
486via this web page:
487.display
488&url(http://lists.alioth.debian.org/mailman/listinfo/pkg-exim4-users)
489.endd
490Please ask Debian-specific questions on this list and not on the general Exim
491lists.
9b371988 492
f89d2485 493.section "Exim training" "SECID4"
9b371988 494.cindex "training courses"
595028e4
PH
495Training courses in Cambridge (UK) used to be run annually by the author of
496Exim, before he retired. At the time of writing, there are no plans to run
497further Exim courses in Cambridge. However, if that changes, relevant
498information will be posted at &url(http://www-tus.csx.cam.ac.uk/courses/exim/).
168e428f 499
f89d2485 500.section "Bug reports" "SECID5"
9b371988
PH
501.cindex "bug reports"
502.cindex "reporting bugs"
595028e4
PH
503Reports of obvious bugs &new("can be emailed to &'bugs@exim.org'& or reported
504via the Bugzilla (&url(http://bugs.exim.org)).") However, if you are unsure
505whether some behaviour is a bug or not, the best thing to do is to post a
506message to the &'exim-dev'& mailing list and have it discussed.
168e428f
PH
507
508
509
9b371988
PH
510.section "Where to find the Exim distribution" "SECTavail"
511.cindex "FTP site"
512.cindex "distribution" "ftp site"
168e428f 513The master ftp site for the Exim distribution is
9b371988
PH
514.display
515&*ftp://ftp.csx.cam.ac.uk/pub/software/email/exim*&
516.endd
168e428f 517This is mirrored by
9b371988
PH
518.display
519&*ftp://ftp.exim.org/pub/exim*&
520.endd
521The file references that follow are relative to the &_exim_& directories at
522these sites. There are now quite a number of independent mirror sites around
523the world. Those that I know about are listed in the file called &_Mirrors_&.
524
525Within the &_exim_& directory there are subdirectories called &_exim3_& (for
526previous Exim 3 distributions), &_exim4_& (for the latest Exim 4
527distributions), and &_Testing_& for testing versions. In the &_exim4_&
168e428f 528subdirectory, the current release can always be found in files called
9b371988
PH
529.display
530&_exim-n.nn.tar.gz_&
531&_exim-n.nn.tar.bz2_&
532.endd
533where &'n.nn'& is the highest such version number in the directory. The two
168e428f 534files contain identical data; the only difference is the type of compression.
9b371988 535The &_.bz2_& file is usually a lot smaller than the &_.gz_& file.
168e428f 536
9b371988
PH
537.cindex "distribution" "signing details"
538.cindex "distribution" "public key"
539.cindex "public key for signed distribution"
168e428f
PH
540The distributions are currently signed with Philip Hazel's GPG key. The
541corresponding public key is available from a number of keyservers, and there is
9b371988 542also a copy in the file &_Public-Key_&. The signatures for the tar bundles are
168e428f 543in:
9b371988
PH
544.display
545&_exim-n.nn.tar.gz.sig_&
546&_exim-n.nn.tar.bz2.sig_&
547.endd
168e428f 548For each released version, the log of changes is made separately available in a
9b371988 549separate file in the directory &_ChangeLogs_& so that it is possible to
168e428f
PH
550find out what has changed without having to download the entire distribution.
551
9b371988 552.cindex "documentation" "available formats"
168e428f
PH
553The main distribution contains ASCII versions of this specification and other
554documentation; other formats of the documents are available in separate files
9b371988
PH
555inside 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
562These tar files contain only the &_doc_& directory, not the complete
563distribution, and are also available in &_.bz2_& as well as &_.gz_& forms.
168e428f 564
168e428f 565
f89d2485 566.section "Limitations" "SECID6"
9b371988
PH
567.ilist
568.cindex "limitations of Exim"
569.cindex "bang paths" "not handled by Exim"
570Exim is designed for use as an Internet MTA, and therefore handles addresses in
571RFC 2822 domain format only. It cannot handle UUCP &"bang paths"&, though
572simple two-component bang paths can be converted by a straightforward rewriting
573configuration. This restriction does not prevent Exim from being interfaced to
574UUCP as a transport mechanism, provided that domain addresses are used.
575.next
576.cindex "domainless addresses"
577.cindex "address" "without domain"
168e428f
PH
578Exim insists that every address it handles has a domain attached. For incoming
579local messages, domainless addresses are automatically qualified with a
580configured domain value. Configuration options specify from which remote
581systems unqualified addresses are acceptable. These are then qualified on
582arrival.
9b371988
PH
583.next
584.cindex "transport" "external"
585.cindex "external transports"
586The only external transport mechanisms that are currently implemented are SMTP
587and LMTP over a TCP/IP network (including support for IPv6). However, a pipe
168e428f 588transport is available, and there are facilities for writing messages to files
9b371988
PH
589and pipes, optionally in &'batched SMTP'& format; these facilities can be used
590to send messages to other transport mechanisms such as UUCP, provided they can
591handle domain-style addresses. Batched SMTP input is also catered for.
592.next
593Exim is not designed for storing mail for dial-in hosts. When the volumes of
594such mail are large, it is better to get the messages &"delivered"& into files
168e428f
PH
595(that is, off Exim's queue) and subsequently passed on to the dial-in hosts by
596other means.
9b371988
PH
597.next
598Although Exim does have basic facilities for scanning incoming messages, these
168e428f
PH
599are not comprehensive enough to do full virus or spam scanning. Such operations
600are best carried out using additional specialized software packages. If you
601compile Exim with the content-scanning extension, straightforward interfaces to
602a number of common scanners are provided.
9b371988 603.endlist
168e428f
PH
604
605
f89d2485 606.section "Run time configuration" "SECID7"
168e428f
PH
607Exim's run time configuration is held in a single text file that is divided
608into a number of sections. The entries in this file consist of keywords and
609values, in the style of Smail 3 configuration files. A default configuration
610file which is suitable for simple online installations is provided in the
9b371988 611distribution, and is described in chapter &<<CHAPdefconfil>>& below.
168e428f
PH
612
613
f89d2485 614.section "Calling interface" "SECID8"
9b371988 615.cindex "Sendmail compatibility" "command line interface"
168e428f 616Like many MTAs, Exim has adopted the Sendmail command line interface so that it
9b371988
PH
617can be a straight replacement for &_/usr/lib/sendmail_& or
618&_/usr/sbin/sendmail_& when sending mail, but you do not need to know anything
168e428f
PH
619about Sendmail in order to run Exim. For actions other than sending messages,
620Sendmail-compatible options also exist, but those that produce output (for
9b371988 621example, &%-bp%&, which lists the messages on the queue) do so in Exim's own
168e428f 622format. There are also some additional options that are compatible with Smail
9b371988 6233, and some further options that are new to Exim. Chapter &<<CHAPcommandline>>&
168e428f
PH
624documents all Exim's command line options. This information is automatically
625made into the man page that forms part of the Exim distribution.
626
627Control of messages on the queue can be done via certain privileged command
9b371988
PH
628line options. There is also an optional monitor program called &'eximon'&,
629which displays current information in an X window, and which contains a menu
168e428f
PH
630interface to Exim's command line administration options.
631
632
633
f89d2485 634.section "Terminology" "SECID9"
9b371988
PH
635.cindex "terminology definitions"
636.cindex "body of message" "definition of"
637The &'body'& of a message is the actual data that the sender wants to transmit.
638It is the last part of a message, and is separated from the &'header'& (see
168e428f
PH
639below) by a blank line.
640
9b371988 641.cindex "bounce message" "definition of"
168e428f 642When a message cannot be delivered, it is normally returned to the sender in a
9b371988
PH
643delivery failure message or a &"non-delivery report"& (NDR). The term
644&'bounce'& is commonly used for this action, and the error reports are often
645called &'bounce messages'&. This is a convenient shorthand for &"delivery
646failure error report"&. Such messages have an empty sender address in the
647message's &'envelope'& (see below) to ensure that they cannot themselves give
648rise to further bounce messages.
649
650The term &'default'& appears frequently in this manual. It is used to qualify a
168e428f
PH
651value which is used in the absence of any setting in the configuration. It may
652also qualify an action which is taken unless a configuration setting specifies
653otherwise.
654
9b371988 655The term &'defer'& is used when the delivery of a message to a specific
168e428f 656destination cannot immediately take place for some reason (a remote host may be
9b371988 657down, or a user's local mailbox may be full). Such deliveries are &'deferred'&
168e428f
PH
658until a later time.
659
9b371988
PH
660The word &'domain'& is sometimes used to mean all but the first component of a
661host's name. It is &'not'& used in that sense here, where it normally refers to
662the part of an email address following the @ sign.
168e428f 663
f89d2485 664.cindex "envelope, definition of"
9b371988
PH
665.cindex "sender" "definition of"
666A message in transit has an associated &'envelope'&, as well as a header and a
168e428f
PH
667body. The envelope contains a sender address (to which bounce messages should
668be delivered), and any number of recipient addresses. References to the
669sender or the recipients of a message usually mean the addresses in the
670envelope. An MTA uses these addresses for delivery, and for returning bounce
671messages, not the addresses that appear in the header lines.
672
f89d2485 673.cindex "message" "header, definition of"
9b371988
PH
674.cindex "header section" "definition of"
675The &'header'& of a message is the first part of a message's text, consisting
676of 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
168e428f
PH
678indenting the continuations. The header is separated from the body by a blank
679line.
680
9b371988
PH
681.cindex "local part" "definition of"
682.cindex "domain" "definition of"
683The term &'local part'&, which is taken from RFC 2822, is used to refer to that
168e428f 684part of an email address that precedes the @ sign. The part that follows the
9b371988 685@ sign is called the &'domain'& or &'mail domain'&.
168e428f 686
9b371988 687.cindex "local delivery" "definition of"
f89d2485 688.cindex "remote delivery, definition of"
9b371988 689The terms &'local delivery'& and &'remote delivery'& are used to distinguish
168e428f 690delivery to a file or a pipe on the local host from delivery by SMTP over
068aaea8 691TCP/IP to another host. As far as Exim is concerned, all hosts other than the
9b371988 692host it is running on are &'remote'&.
168e428f 693
9b371988
PH
694.cindex "return path" "definition of"
695&'Return path'& is another name that is used for the sender address in a
168e428f
PH
696message's envelope.
697
9b371988
PH
698.cindex "queue" "definition of"
699The term &'queue'& is used to refer to the set of messages awaiting delivery,
168e428f
PH
700because this term is in widespread use in the context of MTAs. However, in
701Exim's case the reality is more like a pool than a queue, because there is
702normally no ordering of waiting messages.
703
9b371988
PH
704.cindex "queue runner" "definition of"
705The term &'queue runner'& is used to describe a process that scans the queue
168e428f 706and attempts to deliver those messages whose retry times have come. This term
9b371988 707is used by other MTAs, and also relates to the command &%runq%&, but in Exim
168e428f
PH
708the waiting messages are normally processed in an unpredictable order.
709
9b371988
PH
710.cindex "spool directory" "definition of"
711The term &'spool directory'& is used for a directory in which Exim keeps the
712messages on its queue &-- that is, those that it is in the process of
168e428f 713delivering. This should not be confused with the directory in which local
9b371988
PH
714mailboxes are stored, which is called a &"spool directory"& by some people. In
715the Exim documentation, &"spool"& is always used in the first sense.
168e428f
PH
716
717
718
719
720
721
9b371988
PH
722. ////////////////////////////////////////////////////////////////////////////
723. ////////////////////////////////////////////////////////////////////////////
168e428f 724
f89d2485 725.chapter "Incorporated code" "CHID2"
9b371988
PH
726.cindex "incorporated code"
727.cindex "regular expressions" "library"
728.cindex "PCRE"
168e428f
PH
729A number of pieces of external code are included in the Exim distribution.
730
9b371988
PH
731.ilist
732Regular expressions are supported in the main Exim program and in the Exim
733monitor using the freely-distributable PCRE library, copyright &copy;
734University 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
736the PCRE library in other programs, you should obtain and install the full
f89d2485
PH
737version of the library from
738&url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre).
9b371988 739.next
f89d2485 740.cindex "cdb" "acknowledgment"
168e428f
PH
741Support for the cdb (Constant DataBase) lookup method is provided by code
742contributed by Nigel Metheringham of (at the time he contributed it) Planet
9b371988
PH
743Online Ltd. The implementation is completely contained within the code of Exim.
744It does not link against an external cdb library. The code contains the
745following statements:
746
747.blockquote
748Copyright &copy; 1998 Nigel Metheringham, Planet Online Ltd
749
168e428f
PH
750This program is free software; you can redistribute it and/or modify it under
751the terms of the GNU General Public License as published by the Free Software
752Foundation; either version 2 of the License, or (at your option) any later
753version.
168e428f
PH
754This code implements Dan Bernstein's Constant DataBase (cdb) spec. Information,
755the spec and sample code for cdb can be obtained from
f89d2485
PH
756&url(http://www.pobox.com/~djb/cdb.html). This implementation borrows
757some code from Dan Bernstein's implementation (which has no license
758restrictions applied to it).
9b371988
PH
759.endblockquote
760.next
761.cindex "SPA authentication"
762.cindex "Samba project"
763.cindex "Microsoft Secure Password Authentication"
764Client support for Microsoft's &'Secure Password Authentication'& is provided
168e428f
PH
765by code contributed by Marc Prud'hommeaux. Server support was contributed by
766Tom Kistner. This includes code taken from the Samba project, which is released
767under the Gnu GPL.
9b371988
PH
768.next
769.cindex "Cyrus"
770.cindex "&'pwcheck'& daemon"
771.cindex "&'pwauthd'& daemon"
772Support for calling the Cyrus &'pwcheck'& and &'saslauthd'& daemons is provided
168e428f
PH
773by code taken from the Cyrus-SASL library and adapted by Alexander S.
774Sabourenkov. The permission notice appears below, in accordance with the
775conditions expressed therein.
9b371988
PH
776
777.blockquote
778Copyright &copy; 2001 Carnegie Mellon University. All rights reserved.
779
168e428f
PH
780Redistribution and use in source and binary forms, with or without
781modification, are permitted provided that the following conditions
782are met:
168e428f 783
9b371988
PH
784.olist
785Redistributions of source code must retain the above copyright
786notice, this list of conditions and the following disclaimer.
787.next
788Redistributions in binary form must reproduce the above copyright
168e428f
PH
789notice, this list of conditions and the following disclaimer in
790the documentation and/or other materials provided with the
791distribution.
9b371988
PH
792.next
793The name &"Carnegie Mellon University"& must not be used to
168e428f
PH
794endorse or promote products derived from this software without
795prior written permission. For permission or any other legal
796details, please contact
9b371988 797.display
068aaea8
PH
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
9b371988
PH
804.endd
805.next
806Redistributions of any form whatsoever must retain the following
168e428f 807acknowledgment:
9b371988
PH
808
809&"This product includes software developed by Computing Services
810at Carnegie Mellon University (&url(http://www.cmu.edu/computing/)."&
811
168e428f
PH
812CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
813THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
814AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
815FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
816WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
817AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
818OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
9b371988
PH
819.endlist
820.endblockquote
168e428f 821
9b371988 822.next
f89d2485 823.cindex "Exim monitor" "acknowledgment"
9b371988
PH
824.cindex "X-windows"
825.cindex "Athena"
168e428f
PH
826The Exim Monitor program, which is an X-Window application, includes
827modified versions of the Athena StripChart and TextPop widgets.
828This code is copyright by DEC and MIT, and their permission notice appears
829below, in accordance with the conditions expressed therein.
9b371988
PH
830
831.blockquote
168e428f
PH
832Copyright 1987, 1988 by Digital Equipment Corporation, Maynard, Massachusetts,
833and the Massachusetts Institute of Technology, Cambridge, Massachusetts.
9b371988 834
168e428f 835All Rights Reserved
9b371988 836
168e428f
PH
837Permission to use, copy, modify, and distribute this software and its
838documentation for any purpose and without fee is hereby granted,
839provided that the above copyright notice appear in all copies and that
840both that copyright notice and this permission notice appear in
841supporting documentation, and that the names of Digital or MIT not be
842used in advertising or publicity pertaining to distribution of the
843software without specific, written prior permission.
9b371988 844
168e428f
PH
845DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
846ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
847DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
848ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
849WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
850ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
851SOFTWARE.
9b371988 852.endblockquote
168e428f 853
9b371988
PH
854.next
855Many people have contributed code fragments, some large, some small, that were
168e428f 856not covered by any specific licence requirements. It is assumed that the
f89d2485 857contributors are happy to see their code incorporated into Exim under the GPL.
9b371988 858.endlist
168e428f
PH
859
860
861
862
863
9b371988
PH
864. ////////////////////////////////////////////////////////////////////////////
865. ////////////////////////////////////////////////////////////////////////////
168e428f 866
f89d2485 867.chapter "How Exim receives and delivers mail" "CHID11" &&&
9b371988 868 "Receiving and delivering mail"
168e428f
PH
869
870
f89d2485 871.section "Overall philosophy" "SECID10"
9b371988 872.cindex "design philosophy"
168e428f
PH
873Exim is designed to work efficiently on systems that are permanently connected
874to the Internet and are handling a general mix of mail. In such circumstances,
875most messages can be delivered immediately. Consequently, Exim does not
876maintain independent queues of messages for specific domains or hosts, though
877it does try to send several messages in a single SMTP connection after a host
878has been down, and it also maintains per-host retry information.
879
880
f89d2485 881.section "Policy control" "SECID11"
9b371988 882.cindex "policy control" "overview"
168e428f
PH
883Policy controls are now an important feature of MTAs that are connected to the
884Internet. Perhaps their most important job is to stop MTAs being abused as
9b371988
PH
885&"open relays"& by misguided individuals who send out vast amounts of
886unsolicited junk, and want to disguise its source. Exim provides flexible
887facilities for specifying policy controls on incoming mail:
168e428f 888
9b371988
PH
889.ilist
890.cindex "&ACL;" "introduction"
168e428f 891Exim 4 (unlike previous versions of Exim) implements policy controls on
9b371988 892incoming mail by means of &'Access Control Lists'& (ACLs). Each list is a
168e428f
PH
893series of statements that may either grant or deny access. ACLs can be used at
894several places in the SMTP dialogue while receiving a message from a remote
9b371988
PH
895host. However, the most common places are after each RCPT command, and at the
896very end of the message. The sysadmin can specify conditions for accepting or
897rejecting individual recipients or the entire message, respectively, at these
898two points (see chapter &<<CHAPACL>>&). Denial of access results in an SMTP
168e428f 899error code.
9b371988
PH
900.next
901An ACL is also available for locally generated, non-SMTP messages. In this
168e428f 902case, the only available actions are to accept or deny the entire message.
9b371988
PH
903.next
904When Exim is compiled with the content-scanning extension, facilities are
168e428f
PH
905provided in the ACL mechanism for passing the message to external virus and/or
906spam scanning software. The result of such a scan is passed back to the ACL,
907which can then use it to decide what to do with the message.
9b371988
PH
908.next
909When a message has been received, either from a remote host or from the local
f89d2485 910host, but before the final acknowledgment has been sent, a locally supplied C
9b371988
PH
911function called &[local_scan()]& can be run to inspect the message and decide
912whether to accept it or not (see chapter &<<CHAPlocalscan>>&). If the message
913is accepted, the list of recipients can be modified by the function.
914.next
915Using the &[local_scan()]& mechanism is another way of calling external scanner
916software. The &%SA-Exim%& add-on package works this way. It does not require
917Exim to be compiled with the content-scanning extension.
918.next
919After a message has been accepted, a further checking mechanism is available in
920the form of the &'system filter'& (see chapter &<<CHAPsystemfilter>>&). This
921runs at the start of every delivery process.
922.endlist
923
924
925
f89d2485 926.section "User filters" "SECID12"
9b371988
PH
927.cindex "filter" "introduction"
928.cindex "Sieve filter"
168e428f 929In a conventional Exim configuration, users are able to run private filters by
9b371988
PH
930setting up appropriate &_.forward_& files in their home directories. See
931chapter &<<CHAPredirect>>& (about the &(redirect)& router) for the
932configuration needed to support this, and the separate document entitled
933&'Exim's interfaces to mail filtering'& for user details. Two different kinds
934of filtering are available:
935
936.ilist
937Sieve filters are written in the standard filtering language that is defined
168e428f 938by RFC 3028.
9b371988
PH
939.next
940Exim filters are written in a syntax that is unique to Exim, but which is more
168e428f 941powerful than Sieve, which it pre-dates.
9b371988 942.endlist
168e428f
PH
943
944User filters are run as part of the routing process, described below.
945
946
947
9b371988
PH
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"
956Every message handled by Exim is given a &'message id'& which is sixteen
168e428f 957characters long. It is divided into three parts, separated by hyphens, for
9b371988 958example &`16VDhn-0001bo-D3`&. Each part is a sequence of letters and digits,
168e428f
PH
959normally encoding numbers in base 62. However, in the Darwin operating
960system (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
962id is used to construct file names, and the names of files in those systems are
068aaea8 963not always case-sensitive.
168e428f 964
9b371988 965.cindex "pid (process id)" "re-use of"
168e428f
PH
966The detail of the contents of the message id have changed as Exim has evolved.
967Earlier versions relied on the operating system not re-using a process id (pid)
968within one second. On modern operating systems, this assumption can no longer
969be made, so the algorithm had to be changed. To retain backward compatibility,
970the format of the message id was retained, which is why the following rules are
971somewhat eccentric:
972
9b371988
PH
973.ilist
974The first six characters of the message id are the time at which the message
168e428f
PH
975started to be received, to a granularity of one second. That is, this field
976contains the number of seconds since the start of the epoch (the normal Unix
977way of representing the date and time of day).
9b371988
PH
978.next
979After the first hyphen, the next six characters are the id of the process that
168e428f 980received the message.
9b371988
PH
981.next
982There are two different possibilities for the final two characters:
983.olist
0a4e3112 984.oindex "&%localhost_number%&"
9b371988 985If &%localhost_number%& is not set, this value is the fractional part of the
168e428f
PH
986time of reception, normally in units of 1/2000 of a second, but for systems
987that must use base 36 instead of base 62 (because of case-insensitive file
988systems), the units are 1/1000 of a second.
9b371988
PH
989.next
990If &%localhost_number%& is set, it is multiplied by 200 (100) and added to
168e428f
PH
991the fractional part of the time, which in this case is in units of 1/200
992(1/100) of a second.
9b371988
PH
993.endlist
994.endlist
168e428f
PH
995
996After a message has been received, Exim waits for the clock to tick at the
997appropriate resolution before proceeding, so that if another message is
998received by the same process, or by another process with the same (re-used)
999pid, it is guaranteed that the time will be different. In most cases, the clock
1000will already have ticked while the message was being received.
1001
1002
f89d2485 1003.section "Receiving mail" "SECID13"
9b371988
PH
1004.cindex "receiving mail"
1005.cindex "message" "reception"
068aaea8
PH
1006The only way Exim can receive mail from another host is using SMTP over
1007TCP/IP, in which case the sender and recipient addresses are transferred using
168e428f
PH
1008SMTP commands. However, from a locally running process (such as a user's MUA),
1009there are several possibilities:
1010
9b371988
PH
1011.ilist
1012If the process runs Exim with the &%-bm%& option, the message is read
168e428f 1013non-interactively (usually via a pipe), with the recipients taken from the
9b371988
PH
1014command line, or from the body of the message if &%-t%& is also used.
1015.next
1016If the process runs Exim with the &%-bS%& option, the message is also read
168e428f
PH
1017non-interactively, but in this case the recipients are listed at the start of
1018the message in a series of SMTP RCPT commands, terminated by a DATA
9b371988 1019command. This is so-called &"batch SMTP"& format,
168e428f
PH
1020but it isn't really SMTP. The SMTP commands are just another way of passing
1021envelope addresses in a non-interactive submission.
9b371988
PH
1022.next
1023If the process runs Exim with the &%-bs%& option, the message is read
168e428f
PH
1024interactively, using the SMTP protocol. A two-way pipe is normally used for
1025passing data between the local process and the Exim process.
9b371988 1026This is &"real"& SMTP and is handled in the same way as SMTP over TCP/IP. For
168e428f 1027example, the ACLs for SMTP commands are used for this form of submission.
9b371988
PH
1028.next
1029A local process may also make a TCP/IP call to the host's loopback address
168e428f
PH
1030(127.0.0.1) or any other of its IP addresses. When receiving messages, Exim
1031does not treat the loopback address specially. It treats all such connections
1032in the same way as connections from other hosts.
9b371988 1033.endlist
168e428f
PH
1034
1035
f89d2485 1036.cindex "message sender, constructed by Exim"
9b371988 1037.cindex "sender" "constructed by Exim"
168e428f
PH
1038In the three cases that do not involve TCP/IP, the sender address is
1039constructed from the login name of the user that called Exim and a default
9b371988 1040qualification domain (which can be set by the &%qualify_domain%& configuration
168e428f
PH
1041option). For local or batch SMTP, a sender address that is passed using the
1042SMTP MAIL command is ignored. However, the system administrator may allow
9b371988 1043certain users (&"trusted users"&) to specify a different sender address
168e428f 1044unconditionally, or all users to specify certain forms of different sender
9b371988
PH
1045address. The &%-f%& option or the SMTP MAIL command is used to specify these
1046different addresses. See section &<<SECTtrustedadmin>>& for details of trusted
1047users, and the &%untrusted_set_sender%& option for a way of allowing untrusted
168e428f
PH
1048users to change sender addresses.
1049
1050Messages received by either of the non-interactive mechanisms are subject to
1051checking 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
1053number of ACLs that operate at different times during the SMTP session. Either
1054individual recipients, or the entire message, can be rejected if local policy
9b371988
PH
1055requirements are not met. The &[local_scan()]& function (see chapter
1056&<<CHAPlocalscan>>&) is run for all incoming messages.
168e428f
PH
1057
1058Exim can be configured not to start a delivery process when a message is
1059received; this can be unconditional, or depend on the number of incoming SMTP
1060connections or the system load. In these situations, new messages wait on the
1061queue until a queue runner process picks them up. However, in standard
1062configurations under normal conditions, delivery is started as soon as a
1063message is received.
1064
1065
1066
1067
1068
f89d2485 1069.section "Handling an incoming message" "SECID14"
9b371988
PH
1070.cindex "spool directory" "files that hold a message"
1071.cindex "file" "how a message is held"
168e428f
PH
1072When Exim accepts a message, it writes two files in its spool directory. The
1073first contains the envelope information, the current status of the message, and
1074the header lines, and the second contains the body of the message. The names of
9b371988
PH
1075the two spool files consist of the message id, followed by &`-H`& for the
1076file containing the envelope and header, and &`-D`& for the data file.
168e428f 1077
9b371988 1078.cindex "spool directory" "&_input_& sub-directory"
168e428f 1079By default all these message files are held in a single directory called
9b371988 1080&_input_& inside the general Exim spool directory. Some operating systems do
c0712871 1081not perform very well if the number of files in a directory gets large; to
9b371988 1082improve performance in such cases, the &%split_spool_directory%& option can be
168e428f 1083used. This causes Exim to split up the input files into 62 sub-directories
db9452a9 1084whose names are single letters or digits. When this is done, the queue is
c0712871
PH
1085processed one sub-directory at a time instead of all at once, which can improve
1086overall performance even when there are not enough files in each directory to
db9452a9 1087affect file system performance.
168e428f
PH
1088
1089The envelope information consists of the address of the message's sender and
1090the addresses of the recipients. This information is entirely separate from
1091any addresses contained in the header lines. The status of the message includes
1092a list of recipients who have already received the message. The format of the
9b371988 1093first spool file is described in chapter &<<CHAPspool>>&.
168e428f 1094
9b371988 1095.cindex "rewriting" "addresses"
168e428f 1096Address rewriting that is specified in the rewrite section of the configuration
9b371988 1097(see chapter &<<CHAPrewrite>>&) is done once and for all on incoming addresses,
168e428f
PH
1098both in the header lines and the envelope, at the time the message is accepted.
1099If during the course of delivery additional addresses are generated (for
1100example, via aliasing), these new addresses are rewritten as soon as they are
1101generated. At the time a message is actually delivered (transported) further
1102rewriting can take place; because this is a transport option, it can be
1103different for different forms of delivery. It is also possible to specify the
1104addition or removal of certain header lines at the time the message is
9b371988
PH
1105delivered (see chapters &<<CHAProutergeneric>>& and
1106&<<CHAPtransportgeneric>>&).
168e428f
PH
1107
1108
1109
f89d2485 1110.section "Life of a message" "SECID15"
9b371988
PH
1111.cindex "message" "life of"
1112.cindex "message" "frozen"
168e428f
PH
1113A message remains in the spool directory until it is completely delivered to
1114its recipients or to an error address, or until it is deleted by an
1115administrator or by the user who originally created it. In cases when delivery
9b371988
PH
1116cannot proceed &-- for example, when a message can neither be delivered to its
1117recipients nor returned to its sender, the message is marked &"frozen"& on the
168e428f
PH
1118spool, and no more deliveries are attempted.
1119
9b371988
PH
1120.cindex "frozen messages" "thawing"
1121.cindex "message" "thawing frozen"
1122An administrator can &"thaw"& such messages when the problem has been
1123corrected, and can also freeze individual messages by hand if necessary. In
1124addition, an administrator can force a delivery error, causing a bounce message
1125to be sent.
1126
0a4e3112
PH
1127.oindex "&%timeout_frozen_after%&"
1128.oindex "&%ignore_bounce_errors_after%&"
9b371988
PH
1129There are options called &%ignore_bounce_errors_after%& and
1130&%timeout_frozen_after%&, which discard frozen messages after a certain time.
068aaea8 1131The first applies only to frozen bounces, the second to any frozen messages.
168e428f 1132
9b371988
PH
1133.cindex "message" "log file for"
1134.cindex "log" "file for each message"
168e428f 1135While Exim is working on a message, it writes information about each delivery
068aaea8 1136attempt to its main log file. This includes successful, unsuccessful, and
9b371988
PH
1137delayed deliveries for each recipient (see chapter &<<CHAPlog>>&). The log
1138lines are also written to a separate &'message log'& file for each message.
1139These logs are solely for the benefit of the administrator, and are normally
1140deleted along with the spool files when processing of a message is complete.
168e428f 1141The use of individual message logs can be disabled by setting
9b371988
PH
1142&%no_message_logs%&; this might give an improvement in performance on very busy
1143systems.
168e428f 1144
9b371988
PH
1145.cindex "journal file"
1146.cindex "file" "journal"
168e428f
PH
1147All the information Exim itself needs to set up a delivery is kept in the first
1148spool file, along with the header lines. When a successful delivery occurs, the
1149address is immediately written at the end of a journal file, whose name is the
9b371988
PH
1150message id followed by &`-J`&. At the end of a delivery run, if there are some
1151addresses left to be tried again later, the first spool file (the &`-H`& file)
168e428f
PH
1152is updated to indicate which these are, and the journal file is then deleted.
1153Updating the spool file is done by writing a new file and renaming it, to
1154minimize the possibility of data loss.
1155
1156Should the system or the program crash after a successful delivery but before
1157the spool file has been updated, the journal is left lying around. The next
1158time Exim attempts to deliver the message, it reads the journal file and
1159updates the spool file before proceeding. This minimizes the chances of double
1160deliveries caused by crashes.
1161
1162
1163
9b371988
PH
1164.section "Processing an address for delivery" "SECTprocaddress"
1165.cindex "drivers" "definition of"
1166.cindex "router" "definition of"
1167.cindex "transport" "definition of"
1168The main delivery processing elements of Exim are called &'routers'& and
1169&'transports'&, and collectively these are known as &'drivers'&. Code for a
168e428f
PH
1170number of them is provided in the source distribution, and compile-time options
1171specify which ones are included in the binary. Run time options specify which
1172ones are actually used for delivering messages.
1173
9b371988
PH
1174.cindex "drivers" "instance definition"
1175Each driver that is specified in the run time configuration is an &'instance'&
168e428f 1176of that particular driver type. Multiple instances are allowed; for example,
9b371988 1177you can set up several different &(smtp)& transports, each with different
168e428f
PH
1178option values that might specify different ports or different timeouts. Each
1179instance has its own identifying name. In what follows we will normally use the
1180instance name when discussing one particular instance (that is, one specific
1181configuration of the driver), and the generic driver name when discussing
1182the driver's features in general.
1183
9b371988 1184A &'router'& is a driver that operates on an address, either determining how
068aaea8 1185its delivery should happen, by assigning it to a specific transport, or
168e428f
PH
1186converting the address into one or more new addresses (for example, via an
1187alias file). A router may also explicitly choose to fail an address, causing it
1188to be bounced.
1189
9b371988
PH
1190A &'transport'& is a driver that transmits a copy of the message from Exim's
1191spool to some destination. There are two kinds of transport: for a &'local'&
168e428f 1192transport, the destination is a file or a pipe on the local host, whereas for a
9b371988 1193&'remote'& transport the destination is some other host. A message is passed
168e428f
PH
1194to a specific transport as a result of successful routing. If a message has
1195several recipients, it may be passed to a number of different transports.
1196
9b371988 1197.cindex "preconditions" "definition of"
168e428f
PH
1198An address is processed by passing it to each configured router instance in
1199turn, subject to certain preconditions, until a router accepts the address or
1200specifies that it should be bounced. We will describe this process in more
068aaea8
PH
1201detail shortly. First, as a simple example, we consider how each recipient
1202address in a message is processed in a small configuration of three routers.
168e428f 1203
068aaea8 1204To make this a more concrete example, it is described in terms of some actual
168e428f
PH
1205routers, but remember, this is only an example. You can configure Exim's
1206routers in many different ways, and there may be any number of routers in a
1207configuration.
1208
1209The first router that is specified in a configuration is often one that handles
1210addresses in domains that are not recognized specially by the local host. These
1211are typically addresses for arbitrary domains on the Internet. A precondition
1212is set up which looks for the special domains known to the host (for example,
9b371988 1213its own domain name), and the router is run for addresses that do &'not'&
168e428f
PH
1214match. Typically, this is a router that looks up domains in the DNS in order to
1215find the hosts to which this address routes. If it succeeds, the address is
068aaea8 1216assigned to a suitable SMTP transport; if it does not succeed, the router is
168e428f
PH
1217configured to fail the address.
1218
068aaea8 1219The second router is reached only when the domain is recognized as one that
9b371988 1220&"belongs"& to the local host. This router does redirection &-- also known as
068aaea8
PH
1221aliasing and forwarding. When it generates one or more new addresses from the
1222original, each of them is routed independently from the start. Otherwise, the
1223router may cause an address to fail, or it may simply decline to handle the
1224address, in which case the address is passed to the next router.
168e428f
PH
1225
1226The final router in many configurations is one that checks to see if the
1227address belongs to a local mailbox. The precondition may involve a check to
1228see if the local part is the name of a login account, or it may look up the
1229local part in a file or a database. If its preconditions are not met, or if
1230the router declines, we have reached the end of the routers. When this happens,
1231the address is bounced.
1232
1233
1234
f89d2485 1235.section "Processing an address for verification" "SECID16"
9b371988
PH
1236.cindex "router" "for verification"
1237.cindex "verifying address" "overview"
168e428f 1238As well as being used to decide how to deliver to an address, Exim's routers
9b371988 1239are also used for &'address verification'&. Verification can be requested as
168e428f 1240one of the checks to be performed in an ACL for incoming messages, on both
9b371988
PH
1241sender and recipient addresses, and it can be tested using the &%-bv%& and
1242&%-bvs%& command line options.
168e428f 1243
9b371988 1244When an address is being verified, the routers are run in &"verify mode"&. This
168e428f
PH
1245does not affect the way the routers work, but it is a state that can be
1246detected. By this means, a router can be skipped or made to behave differently
1247when verifying. A common example is a configuration in which the first router
1248sends all messages to a message-scanning program, unless they have been
1249previously scanned. Thus, the first router accepts all addresses without any
9b371988 1250checking, making it useless for verifying. Normally, the &%no_verify%& option
168e428f
PH
1251would be set for such a router, causing it to be skipped in verify mode.
1252
1253
1254
1255
9b371988
PH
1256.section "Running an individual router" "SECTrunindrou"
1257.cindex "router" "running details"
1258.cindex "preconditions" "checking"
1259.cindex "router" "result of running"
168e428f
PH
1260As explained in the example above, a number of preconditions are checked before
1261running a router. If any are not met, the router is skipped, and the address is
9b371988 1262passed to the next router. When all the preconditions on a router &'are'& met,
168e428f
PH
1263the router is run. What happens next depends on the outcome, which is one of
1264the following:
1265
9b371988
PH
1266.ilist
1267&'accept'&: The router accepts the address, and either assigns it to a
1268transport, or generates one or more &"child"& addresses. Processing the
1269original address ceases,
0a4e3112 1270.oindex "&%unseen%&"
9b371988 1271unless the &%unseen%& option is set on the router. This option
168e428f 1272can be used to set up multiple deliveries with different routing (for example,
9b371988
PH
1273for keeping archive copies of messages). When &%unseen%& is set, the address is
1274passed to the next router. Normally, however, an &'accept'& return marks the
168e428f 1275end of routing.
9b371988 1276
068aaea8
PH
1277Any child addresses generated by the router are processed independently,
1278starting with the first router by default. It is possible to change this by
9b371988
PH
1279setting the &%redirect_router%& option to specify which router to start at for
1280child 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
168e428f
PH
1284requests that the address be passed to another router. By default the address
1285is passed to the next router, but this can be changed by setting the
9b371988 1286&%pass_router%& option. However, (unlike &%redirect_router%&) the named router
168e428f 1287must be below the current router (to avoid loops).
9b371988
PH
1288.next
1289&'decline'&: The router declines to accept the address because it does not
168e428f 1290recognize it at all. By default, the address is passed to the next router, but
9b371988
PH
1291this can be prevented by setting the &%no_more%& option. When &%no_more%& is
1292set, 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
168e428f 1296the generation of a bounce message. There is no further processing of the
9b371988
PH
1297original address unless &%unseen%& is set on the router.
1298.next
1299&'defer'&: The router cannot handle the address at the present time. (A
068aaea8
PH
1300database may be offline, or a DNS lookup may have timed out.) No further
1301processing of the address happens in this delivery attempt. It is tried again
1302next time the message is considered for delivery.
9b371988
PH
1303.next
1304&'error'&: There is some error in the router (for example, a syntax error in
168e428f 1305its configuration). The action is as for defer.
9b371988 1306.endlist
168e428f
PH
1307
1308If an address reaches the end of the routers without having been accepted by
068aaea8 1309any of them, it is bounced as unrouteable. The default error message in this
9b371988
PH
1310situation is &"unrouteable address"&, but you can set your own message by
1311making use of the &%cannot_route_message%& option. This can be set for any
1312router; the value from the last router that &"saw"& the address is used.
168e428f
PH
1313
1314Sometimes while routing you want to fail a delivery when some conditions are
1315met but others are not, instead of passing the address on for further routing.
1316You can do this by having a second router that explicitly fails the delivery
9b371988 1317when the relevant conditions are met. The &(redirect)& router has a &"fail"&
168e428f
PH
1318facility for this purpose.
1319
1320
f89d2485 1321.section "Duplicate addresses" "SECID17"
9b371988 1322.cindex "case of local parts"
f89d2485 1323.cindex "address duplicate, discarding"
db9452a9 1324.cindex "duplicate addresses"
068aaea8
PH
1325Once routing is complete, Exim scans the addresses that are assigned to local
1326and remote transports, and discards any duplicates that it finds. During this
3cb1b51e 1327check, local parts are treated as case-sensitive. This happens only when
db9452a9 1328actually delivering a message; when testing routers with &%-bt%&, all the
3cb1b51e 1329routed addresses are shown.
db9452a9 1330
068aaea8 1331
168e428f 1332
9b371988 1333.section "Router preconditions" "SECTrouprecon"
f89d2485 1334.cindex "router" "preconditions, order of processing"
9b371988 1335.cindex "preconditions" "order of processing"
168e428f
PH
1336The preconditions that are tested for each router are listed below, in the
1337order in which they are tested. The individual configuration options are
9b371988 1338described in more detail in chapter &<<CHAProutergeneric>>&.
168e428f 1339
9b371988
PH
1340.ilist
1341The &%local_part_prefix%& and &%local_part_suffix%& options can specify that
168e428f
PH
1342the local parts handled by the router may or must have certain prefixes and/or
1343suffixes. If a mandatory affix (prefix or suffix) is not present, the router is
1344skipped. These conditions are tested first. When an affix is present, it is
1345removed from the local part before further processing, including the evaluation
1346of any other conditions.
9b371988
PH
1347.next
1348Routers can be designated for use only when not verifying an address, that is,
168e428f 1349only when routing it for delivery (or testing its delivery routing). If the
9b371988 1350&%verify%& option is set false, the router is skipped when Exim is verifying an
168e428f 1351address.
9b371988
PH
1352Setting the &%verify%& option actually sets two options, &%verify_sender%& and
1353&%verify_recipient%&, which independently control the use of the router for
168e428f
PH
1354sender and recipient verification. You can set these options directly if
1355you want a router to be used for only one type of verification.
9b371988
PH
1356.next
1357If the &%address_test%& option is set false, the router is skipped when Exim is
1358run with the &%-bt%& option to test an address routing. This can be helpful
1359when the first router sends all new messages to a scanner of some sort; it
1360makes it possible to use &%-bt%& to test subsequent delivery routing without
1361having to simulate the effect of the scanner.
1362.next
1363Routers can be designated for use only when verifying an address, as
1364opposed to routing it for delivery. The &%verify_only%& option controls this.
1365.next
1366Individual routers can be explicitly skipped when running the routers to
1367check an address given in the SMTP EXPN command (see the &%expn%& option).
1368.next
1369If the &%domains%& option is set, the domain of the address must be in the set
068aaea8 1370of domains that it defines.
9b371988 1371.next
f89d2485
PH
1372.vindex "&$local_part_prefix$&"
1373.vindex "&$local_part$&"
1374.vindex "&$local_part_suffix$&"
9b371988
PH
1375If the &%local_parts%& option is set, the local part of the address must be in
1376the set of local parts that it defines. If &%local_part_prefix%& or
1377&%local_part_suffix%& is in use, the prefix or suffix is removed from the local
168e428f 1378part before this check. If you want to do precondition tests on local parts
9b371988
PH
1379that include affixes, you can do so by using a &%condition%& option (see below)
1380that uses the variables &$local_part$&, &$local_part_prefix$&, and
1381&$local_part_suffix$& as necessary.
1382.next
f89d2485
PH
1383.vindex "&$local_user_uid$&"
1384.vindex "&$local_user_gid$&"
1385.vindex "&$home$&"
9b371988 1386If the &%check_local_user%& option is set, the local part must be the name of
068aaea8 1387an account on the local host. If this check succeeds, the uid and gid of the
9b371988
PH
1388local user are placed in &$local_user_uid$& and &$local_user_gid$& and the
1389user's home directory is placed in &$home$&; these values can be used in the
1390remaining preconditions.
1391.next
1392If the &%router_home_directory%& option is set, it is expanded at this point,
1393because it overrides the value of &$home$&. If this expansion were left till
1394later, the value of &$home$& as set by &%check_local_user%& would be used in
1395subsequent tests. Having two different values of &$home$& in the same router
168e428f 1396could lead to confusion.
9b371988
PH
1397.next
1398If the &%senders%& option is set, the envelope sender address must be in the
1399set of addresses that it defines.
1400.next
1401If the &%require_files%& option is set, the existence or non-existence of
168e428f 1402specified files is tested.
9b371988
PH
1403.next
1404.cindex "customizing" "precondition"
1405If the &%condition%& option is set, it is evaluated and tested. This option
1406uses an expanded string to allow you to set up your own custom preconditions.
1407Expanded strings are described in chapter &<<CHAPexpand>>&.
1408.endlist
168e428f 1409
168e428f 1410
9b371988
PH
1411Note that &%require_files%& comes near the end of the list, so you cannot use
1412it to check for the existence of a file in which to lookup up a domain, local
168e428f 1413part, or sender. However, as these options are all expanded, you can use the
9b371988
PH
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
168e428f 1416going to use internally, or which are needed by a specific transport (for
9b371988 1417example, &_.procmailrc_&).
168e428f
PH
1418
1419
1420
f89d2485 1421.section "Delivery in detail" "SECID18"
9b371988 1422.cindex "delivery" "in detail"
168e428f
PH
1423When a message is to be delivered, the sequence of events is as follows:
1424
9b371988
PH
1425.ilist
1426If a system-wide filter file is specified, the message is passed to it. The
168e428f
PH
1427filter may add recipients to the message, replace the recipients, discard the
1428message, cause a new message to be generated, or cause the message delivery to
1429fail. The format of the system filter file is the same as for Exim user filter
9b371988
PH
1430files, described in the separate document entitled &'Exim's interfaces to mail
1431filtering'&.
1432.cindex "Sieve filter" "not available for system filter"
1433(&*Note*&: Sieve cannot be used for system filter files.)
1434
1435Some additional features are available in system filters &-- see chapter
1436&<<CHAPsystemfilter>>& for details. Note that a message is passed to the system
168e428f
PH
1437filter only once per delivery attempt, however many recipients it has. However,
1438if there are several delivery attempts because one or more addresses could not
1439be immediately delivered, the system filter is run each time. The filter
9b371988 1440condition &%first_delivery%& can be used to detect the first run of the system
168e428f 1441filter.
9b371988
PH
1442.next
1443Each recipient address is offered to each configured router in turn, subject to
1444its preconditions, until one is able to handle it. If no router can handle the
1445address, that is, if they all decline, the address is failed. Because routers
1446can be targeted at particular domains, several locally handled domains can be
1447processed entirely independently of each other.
1448.next
1449.cindex "routing" "loops in"
1450.cindex "loop" "while routing"
1451A router that accepts an address may assign it to a local or a remote
1452transport. However, the transport is not run at this time. Instead, the address
1453is placed on a list for the particular transport, which will be run later.
068aaea8
PH
1454Alternatively, the router may generate one or more new addresses (typically
1455from alias, forward, or filter files). New addresses are fed back into this
1456process from the top, but in order to avoid loops, a router ignores any address
1457which has an identically-named ancestor that was processed by itself.
9b371988
PH
1458.next
1459When all the routing has been done, addresses that have been successfully
168e428f
PH
1460handled are passed to their assigned transports. When local transports are
1461doing real local deliveries, they handle only one address at a time, but if a
1462local transport is being used as a pseudo-remote transport (for example, to
1463collect batched SMTP messages for transmission by some other means) multiple
1464addresses can be handled. Remote transports can always handle more than one
1465address at a time, but can be configured not to do so, or to restrict multiple
1466addresses to the same domain.
9b371988
PH
1467.next
1468Each local delivery to a file or a pipe runs in a separate process under a
168e428f
PH
1469non-privileged uid, and these deliveries are run one at a time. Remote
1470deliveries also run in separate processes, normally under a uid that is private
9b371988 1471to Exim (&"the Exim user"&), but in this case, several remote deliveries can be
168e428f 1472run in parallel. The maximum number of simultaneous remote deliveries for any
9b371988 1473one message is set by the &%remote_max_parallel%& option.
168e428f
PH
1474The order in which deliveries are done is not defined, except that all local
1475deliveries happen before any remote deliveries.
9b371988
PH
1476.next
1477.cindex "queue runner"
168e428f
PH
1478When it encounters a local delivery during a queue run, Exim checks its retry
1479database to see if there has been a previous temporary delivery failure for the
1480address before running the local transport. If there was a previous failure,
1481Exim does not attempt a new delivery until the retry time for the address is
1482reached. However, this happens only for delivery attempts that are part of a
1483queue run. Local deliveries are always attempted when delivery immediately
1484follows message reception, even if retry times are set for them. This makes for
1485better behaviour if one particular message is causing problems (for example,
1486causing quota overflow, or provoking an error in a filter file).
9b371988
PH
1487.next
1488.cindex "delivery" "retry in remote transports"
168e428f
PH
1489Remote transports do their own retry handling, since an address may be
1490deliverable to one of a number of hosts, each of which may have a different
1491retry time. If there have been previous temporary failures and no host has
1492reached its retry time, no delivery is attempted, whether in a queue run or
9b371988
PH
1493not. See chapter &<<CHAPretry>>& for details of retry strategies.
1494.next
1495If there were any permanent errors, a bounce message is returned to an
168e428f
PH
1496appropriate address (the sender in the common case), with details of the error
1497for each failing address. Exim can be configured to send copies of bounce
1498messages to other addresses.
9b371988
PH
1499.next
1500.cindex "delivery" "deferral"
168e428f
PH
1501If one or more addresses suffered a temporary failure, the message is left on
1502the queue, to be tried again later. Delivery of these addresses is said to be
9b371988
PH
1503&'deferred'&.
1504.next
1505When all the recipient addresses have either been delivered or bounced,
168e428f
PH
1506handling of the message is complete. The spool files and message log are
1507deleted, though the message log can optionally be preserved if required.
9b371988 1508.endlist
168e428f
PH
1509
1510
1511
1512
f89d2485 1513.section "Retry mechanism" "SECID19"
9b371988
PH
1514.cindex "delivery" "retry mechanism"
1515.cindex "retry" "description of mechanism"
1516.cindex "queue runner"
168e428f
PH
1517Exim's mechanism for retrying messages that fail to get delivered at the first
1518attempt is the queue runner process. You must either run an Exim daemon that
9b371988
PH
1519uses the &%-q%& option with a time interval to start queue runners at regular
1520intervals, or use some other means (such as &'cron'&) to start them. If you do
168e428f
PH
1521not arrange for queue runners to be run, messages that fail temporarily at the
1522first attempt will remain on your queue for ever. A queue runner process works
068aaea8 1523its way through the queue, one message at a time, trying each delivery that has
168e428f
PH
1524passed its retry time.
1525You can run several queue runners at once.
1526
1527Exim uses a set of configured rules to determine when next to retry the failing
9b371988
PH
1528address (see chapter &<<CHAPretry>>&). These rules also specify when Exim
1529should give up trying to deliver to the address, at which point it generates a
1530bounce message. If no retry rules are set for a particular host, address, and
1531error combination, no retries are attempted, and temporary errors are treated
1532as permanent.
168e428f
PH
1533
1534
1535
f89d2485 1536.section "Temporary delivery failure" "SECID20"
9b371988 1537.cindex "delivery" "temporary failure"
168e428f
PH
1538There are many reasons why a message may not be immediately deliverable to a
1539particular address. Failure to connect to a remote machine (because it, or the
1540connection to it, is down) is one of the most common. Temporary failures may be
1541detected during routing as well as during the transport stage of delivery.
1542Local deliveries may be delayed if NFS files are unavailable, or if a mailbox
1543is on a file system where the user is over quota. Exim can be configured to
1544impose its own quotas on local mailboxes; where system quotas are set they will
1545also apply.
1546
1547If a host is unreachable for a period of time, a number of messages may be
1548waiting for it by the time it recovers, and sending them in a single SMTP
1549connection is clearly beneficial. Whenever a delivery to a remote host is
1550deferred,
1551
9b371988 1552.cindex "hints database"
168e428f
PH
1553Exim makes a note in its hints database, and whenever a successful
1554SMTP delivery has happened, it looks to see if any other messages are waiting
1555for the same host. If any are found, they are sent over the same SMTP
1556connection, subject to a configuration limit as to the maximum number in any
1557one connection.
1558
1559
1560
1561
f89d2485 1562.section "Permanent delivery failure" "SECID21"
9b371988
PH
1563.cindex "delivery" "permanent failure"
1564.cindex "bounce message" "when generated"
168e428f
PH
1565When a message cannot be delivered to some or all of its intended recipients, a
1566bounce message is generated. Temporary delivery failures turn into permanent
1567errors when their timeout expires. All the addresses that fail in a given
1568delivery attempt are listed in a single message. If the original message has
1569many recipients, it is possible for some addresses to fail in one delivery
1570attempt and others to fail subsequently, giving rise to more than one bounce
1571message. The wording of bounce messages can be customized by the administrator.
9b371988 1572See chapter &<<CHAPemsgcust>>& for details.
168e428f 1573
9b371988
PH
1574.cindex "&'X-Failed-Recipients:'& header line"
1575Bounce messages contain an &'X-Failed-Recipients:'& header line that lists the
168e428f
PH
1576failed addresses, for the benefit of programs that try to analyse such messages
1577automatically.
1578
9b371988 1579.cindex "bounce message" "recipient of"
168e428f
PH
1580A bounce message is normally sent to the sender of the original message, as
1581obtained from the message's envelope. For incoming SMTP messages, this is the
9b371988
PH
1582address given in the MAIL command. However, when an address is expanded via a
1583forward or alias file, an alternative address can be specified for delivery
1584failures of the generated addresses. For a mailing list expansion (see section
1585&<<SECTmailinglists>>&) it is common to direct bounce messages to the manager
1586of the list.
168e428f
PH
1587
1588
1589
f89d2485 1590.section "Failures to deliver bounce messages" "SECID22"
9b371988 1591.cindex "bounce message" "failure to deliver"
168e428f
PH
1592If a bounce message (either locally generated or received from a remote host)
1593itself suffers a permanent delivery failure, the message is left on the queue,
1594but it is frozen, awaiting the attention of an administrator. There are options
068aaea8 1595that can be used to make Exim discard such failed messages, or to keep them
9b371988
PH
1596for only a short time (see &%timeout_frozen_after%& and
1597&%ignore_bounce_errors_after%&).
168e428f
PH
1598
1599
1600
1601
1602
9b371988
PH
1603. ////////////////////////////////////////////////////////////////////////////
1604. ////////////////////////////////////////////////////////////////////////////
168e428f 1605
f89d2485 1606.chapter "Building and installing Exim" "CHID3"
4f578862 1607.scindex IIDbuex "building Exim"
168e428f 1608
f89d2485
PH
1609.section "Unpacking" "SECID23"
1610Exim is distributed as a gzipped or bzipped tar file which, when unpacked,
168e428f 1611creates a directory with the name of the current release (for example,
9b371988
PH
1612&_exim-&version;_&) into which the following files are placed:
1613
1614.table2 140pt
f89d2485
PH
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"
9b371988
PH
1623.endtable
1624
1625Other files whose names begin with &_README_& may also be present. The
168e428f
PH
1626following subdirectories are created:
1627
9b371988 1628.table2 140pt
f89d2485
PH
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"
9b371988
PH
1636.endtable
1637
1638The main utility programs are contained in the &_src_& directory, and are built
1639with the Exim binary. The &_util_& directory contains a few optional scripts
168e428f
PH
1640that may be useful to some sites.
1641
1642
f89d2485 1643.section "Multiple machine architectures and operating systems" "SECID24"
9b371988 1644.cindex "building Exim" "multiple OS/architectures"
168e428f
PH
1645The building process for Exim is arranged to make it easy to build binaries for
1646a number of different architectures and operating systems from the same set of
9b371988
PH
1647source files. Compilation does not take place in the &_src_& directory.
1648Instead, a &'build directory'& is created for each architecture and operating
1649system.
1650.cindex "symbolic link" "to build directory"
168e428f 1651Symbolic links to the sources are installed in this directory, which is where
9b371988
PH
1652the actual building takes place. In most cases, Exim can discover the machine
1653architecture and operating system for itself, but the defaults can be
1654overridden if necessary.
168e428f 1655
168e428f 1656
9b371988
PH
1657.section "DBM libraries" "SECTdb"
1658.cindex "DBM libraries" "discussion of"
1659.cindex "hints database" "DBM files used for"
168e428f
PH
1660Even if you do not use any DBM files in your configuration, Exim still needs a
1661DBM library in order to operate, because it uses indexed files for its hints
1662databases. Unfortunately, there are a number of DBM libraries in existence, and
1663different operating systems often have different ones installed.
1664
9b371988 1665.cindex "Solaris" "DBM library for"
f89d2485
PH
1666.cindex "IRIX, DBM library for"
1667.cindex "BSD, DBM library for"
1668.cindex "Linux, DBM library for"
168e428f
PH
1669If you are using Solaris, IRIX, one of the modern BSD systems, or a modern
1670Linux distribution, the DBM configuration should happen automatically, and you
1671may be able to ignore this section. Otherwise, you may have to learn more than
1672you would like about DBM libraries from what follows.
1673
9b371988 1674.cindex "&'ndbm'& DBM library"
168e428f 1675Licensed versions of Unix normally contain a library of DBM functions operating
9b371988 1676via the &'ndbm'& interface, and this is what Exim expects by default. Free
168e428f
PH
1677versions of Unix seem to vary in what they contain as standard. In particular,
1678some early versions of Linux have no default DBM library, and different
1679distributors have chosen to bundle different libraries with their packaged
f89d2485 1680versions. However, the more recent releases seem to have standardized on the
168e428f
PH
1681Berkeley DB library.
1682
1683Different DBM libraries have different conventions for naming the files they
9b371988 1684use. When a program opens a file called &_dbmfile_&, there are several
168e428f
PH
1685possibilities:
1686
9b371988
PH
1687.olist
1688A traditional &'ndbm'& implementation, such as that supplied as part of
1689Solaris, operates on two files called &_dbmfile.dir_& and &_dbmfile.pag_&.
1690.next
1691.cindex "&'gdbm'& DBM library"
1692The GNU library, &'gdbm'&, operates on a single file. If used via its &'ndbm'&
168e428f 1693compatibility interface it makes two different hard links to it with names
9b371988 1694&_dbmfile.dir_& and &_dbmfile.pag_&, but if used via its native interface, the
168e428f 1695file name is used unmodified.
9b371988
PH
1696.next
1697.cindex "Berkeley DB library"
1698The Berkeley DB package, if called via its &'ndbm'& compatibility interface,
1699operates on a single file called &_dbmfile.db_&, but otherwise looks to the
1700programmer exactly the same as the traditional &'ndbm'& implementation.
1701.next
1702If the Berkeley package is used in its native mode, it operates on a single
1703file called &_dbmfile_&; the programmer's interface is somewhat different to
1704the traditional &'ndbm'& interface.
1705.next
1706To complicate things further, there are several very different versions of the
168e428f 1707Berkeley DB package. Version 1.85 was stable for a very long time, releases
9b371988
PH
17082.&'x'& and 3.&'x'& were current for a while, but the latest versions are now
1709numbered 4.&'x'&. Maintenance of some of the earlier releases has ceased. All
168e428f 1710versions of Berkeley DB can be obtained from
9b371988
PH
1711&url(http://www.sleepycat.com/).
1712.next
1713.cindex "&'tdb'& DBM library"
1714Yet another DBM library, called &'tdb'&, is available from
1715&url(http://download.sourceforge.net/tdb). It has its own interface, and also
1716operates on a single file.
1717.endlist
1718
1719.cindex "USE_DB"
1720.cindex "DBM libraries" "configuration for building"
168e428f
PH
1721Exim and its utilities can be compiled to use any of these interfaces. In order
1722to use any version of the Berkeley DB package in native mode, you must set
1723USE_DB in an appropriate configuration file (typically
9b371988
PH
1724&_Local/Makefile_&). For example:
1725.code
1726USE_DB=yes
1727.endd
168e428f
PH
1728Similarly, for gdbm you set USE_GDBM, and for tdb you set USE_TDB. An
1729error is diagnosed if you set more than one of these.
1730
1731At the lowest level, the build-time configuration sets none of these options,
1732thereby assuming an interface of type (1). However, some operating system
1733configuration files (for example, those for the BSD operating systems and
1734Linux) assume type (4) by setting USE_DB as their default, and the
1735configuration files for Cygwin set USE_GDBM. Anything you set in
9b371988 1736&_Local/Makefile_&, however, overrides these system defaults.
168e428f
PH
1737
1738As well as setting USE_DB, USE_GDBM, or USE_TDB, it may also be
1739necessary to set DBMLIB, to cause inclusion of the appropriate library, as
1740in one of these lines:
9b371988
PH
1741.code
1742DBMLIB = -ldb
1743DBMLIB = -ltdb
1744.endd
168e428f
PH
1745Settings like that will work if the DBM library is installed in the standard
1746place. Sometimes it is not, and the library's header file may also not be in
1747the default path. You may need to set INCLUDE to specify where the header
1748file is, and to specify the path to the library more fully in DBMLIB, as in
1749this example:
9b371988
PH
1750.code
1751INCLUDE=-I/usr/local/include/db-4.1
1752DBMLIB=/usr/local/lib/db-4.1/libdb.a
1753.endd
168e428f 1754There is further detailed discussion about the various DBM libraries in the
9b371988 1755file &_doc/dbm.discuss.txt_& in the Exim distribution.
168e428f
PH
1756
1757
1758
f89d2485 1759.section "Pre-building configuration" "SECID25"
9b371988
PH
1760.cindex "building Exim" "pre-building configuration"
1761.cindex "configuration for building Exim"
1762.cindex "&_Local/Makefile_&"
1763.cindex "&_src/EDITME_&"
168e428f
PH
1764Before building Exim, a local configuration file that specifies options
1765independent of any operating system has to be created with the name
9b371988
PH
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
168e428f
PH
1768therein. These descriptions are therefore not repeated here. If you are
1769building Exim for the first time, the simplest thing to do is to copy
9b371988 1770&_src/EDITME_& to &_Local/Makefile_&, then read it and edit it appropriately.
168e428f
PH
1771
1772There are three settings that you must supply, because Exim will not build
1773without 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
1776maybe EXIM_GROUP as well). The value of CONFIGURE_FILE can in fact be
1777a colon-separated list of file names; Exim uses the first of them that exists.
1778
1779There are a few other parameters that can be specified either at build time or
1780at run time, to enable the same binary to be used on a number of different
1781machines. However, if the locations of Exim's spool directory and log file
1782directory (if not within the spool directory) are fixed, it is recommended that
9b371988 1783you specify them in &_Local/Makefile_& instead of at run time, so that errors
168e428f
PH
1784detected early in Exim's execution (such as a malformed configuration file) can
1785be logged.
1786
9b371988 1787.cindex "content scanning" "specifying at build time"
068aaea8 1788Exim's interfaces for calling virus and spam scanning software directly from
168e428f
PH
1789access control lists are not compiled by default. If you want to include these
1790facilities, you need to set
9b371988
PH
1791.code
1792WITH_CONTENT_SCAN=yes
1793.endd
1794in your &_Local/Makefile_&. For details of the facilities themselves, see
1795chapter &<<CHAPexiscan>>&.
168e428f
PH
1796
1797
9b371988 1798.cindex "&_Local/eximon.conf_&"
3cb1b51e 1799.cindex "&_exim_monitor/EDITME_&"
168e428f 1800If you are going to build the Exim monitor, a similar configuration process is
9b371988
PH
1801required. The file &_exim_monitor/EDITME_& must be edited appropriately for
1802your installation and saved under the name &_Local/eximon.conf_&. If you are
1803happy with the default settings described in &_exim_monitor/EDITME_&,
1804&_Local/eximon.conf_& can be empty, but it must exist.
168e428f
PH
1805
1806This is all the configuration that is needed in straightforward cases for known
1807operating systems. However, the building process is set up so that it is easy
1808to override options that are set by default or by operating-system-specific
1809configuration files, for example to change the name of the C compiler, which
9b371988
PH
1810defaults to &%gcc%&. See section &<<SECToverride>>& below for details of how to
1811do this.
168e428f
PH
1812
1813
1814
f89d2485 1815.section "Support for iconv()" "SECID26"
9b371988
PH
1816.cindex "&[iconv()]& support"
1817.cindex "RFC 2047"
168e428f
PH
1818The contents of header lines in messages may be encoded according to the rules
1819described RFC 2047. This makes it possible to transmit characters that are not
1820in the ASCII character set, and to label them as being in a particular
9b371988 1821character set. When Exim is inspecting header lines by means of the &%$h_%&
168e428f
PH
1822mechanism, 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
9b371988
PH
1824supports the &[iconv()]& function.
1825
1826However, some of the operating systems that supply &[iconv()]& do not support
1827very many conversions. The GNU &%libiconv%& library (available from
1828&url(http://www.gnu.org/software/libiconv/)) can be installed on such
1829systems 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
1832HAVE_ICONV=yes
1833.endd
1834to your &_Local/Makefile_& and rebuild Exim.
1835
1836
1837
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"
168e428f
PH
1844Exim can be built to support encrypted SMTP connections, using the STARTTLS
1845command as per RFC 2487. It can also support legacy clients that expect to
1846start a TLS session immediately on connection to a non-standard port (see the
9b371988 1847&%tls_on_connect_ports%& runtime option and the &%-tls-on-connect%& command
168e428f
PH
1848line option).
1849
1850If you want to build Exim with TLS support, you must first install either the
1851OpenSSL or GnuTLS library. There is no cryptographic code in Exim itself for
1852implementing SSL.
1853
1854If OpenSSL is installed, you should set
9b371988
PH
1855.code
1856SUPPORT_TLS=yes
1857TLS_LIBS=-lssl -lcrypto
1858.endd
1859in &_Local/Makefile_&. You may also need to specify the locations of the
168e428f 1860OpenSSL library and include files. For example:
9b371988
PH
1861.code
1862SUPPORT_TLS=yes
1863TLS_LIBS=-L/usr/local/openssl/lib -lssl -lcrypto
1864TLS_INCLUDE=-I/usr/local/openssl/include/
1865.endd
1866.cindex "USE_GNUTLS"
168e428f 1867If GnuTLS is installed, you should set
9b371988
PH
1868.code
1869SUPPORT_TLS=yes
1870USE_GNUTLS=yes
1871TLS_LIBS=-lgnutls -ltasn1 -lgcrypt
1872.endd
1873in &_Local/Makefile_&, and again you may need to specify the locations of the
168e428f 1874library and include files. For example:
9b371988
PH
1875.code
1876SUPPORT_TLS=yes
1877USE_GNUTLS=yes
1878TLS_LIBS=-L/usr/gnu/lib -lgnutls -ltasn1 -lgcrypt
1879TLS_INCLUDE=-I/usr/gnu/include
1880.endd
168e428f 1881You do not need to set TLS_INCLUDE if the relevant directory is already
9b371988
PH
1882specified in INCLUDE. Details of how to configure Exim to make use of TLS are
1883given in chapter &<<CHAPTLS>>&.
168e428f
PH
1884
1885
1886
1887
f89d2485
PH
1888.section "Use of tcpwrappers" "SECID27"
1889.cindex "tcpwrappers, building Exim to support"
9b371988
PH
1890.cindex "USE_TCP_WRAPPERS"
1891Exim can be linked with the &'tcpwrappers'& library in order to check incoming
1892SMTP calls using the &'tcpwrappers'& control files. This may be a convenient
168e428f 1893alternative to Exim's own checking facilities for installations that are
9b371988
PH
1894already making use of &'tcpwrappers'& for other purposes. To do this, you
1895should 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
1898EXTRALIBS_EXIM. For example, if &'tcpwrappers'& is installed in &_/usr/local_&,
1899you might have
1900.code
1901USE_TCP_WRAPPERS=yes
1902CFLAGS=-O -I/usr/local/include
1903EXTRALIBS_EXIM=-L/usr/local/lib -lwrap
1904.endd
1905in &_Local/Makefile_&. The name to use in the &'tcpwrappers'& control files is
1906&"exim"&. For example, the line
1907.code
1908exim : LOCAL 192.168.1. .friendly.domain.example
1909.endd
1910in your &_/etc/hosts.allow_& file allows connections from the local host, from
1911the subnet 192.168.1.0/24, and from all hosts in &'friendly.domain.example'&.
1912All other connections are denied. Consult the &'tcpwrappers'& documentation for
168e428f
PH
1913further details.
1914
1915
1916
f89d2485 1917.section "Including support for IPv6" "SECID28"
9b371988 1918.cindex "IPv6" "including support for"
168e428f 1919Exim contains code for use on systems that have IPv6 support. Setting
9b371988 1920&`HAVE_IPV6=YES`& in &_Local/Makefile_& causes the IPv6 code to be included;
168e428f
PH
1921it may also be necessary to set IPV6_INCLUDE and IPV6_LIBS on systems
1922where the IPv6 support is not fully integrated into the normal include and
1923library files.
1924
1925Two different types of DNS record for handling IPv6 addresses have been
f89d2485 1926defined. AAAA records (analogous to A records for IPv4) are in use, and are
168e428f
PH
1927currently seen as the mainstream. Another record type called A6 was proposed
1928as better than AAAA because it had more flexibility. However, it was felt to be
9b371988 1929over-complex, and its status was reduced to &"experimental"&. It is not known
168e428f 1930if anyone is actually using A6 records. Exim has support for A6 records, but
9b371988 1931this is included only if you set &`SUPPORT_A6=YES`& in &_Local/Makefile_&. The
168e428f
PH
1932support has not been tested for some time.
1933
1934
1935
f89d2485 1936.section "The building process" "SECID29"
9b371988
PH
1937.cindex "build directory"
1938Once &_Local/Makefile_& (and &_Local/eximon.conf_&, if required) have been
1939created, run &'make'& at the top level. It determines the architecture and
168e428f
PH
1940operating system types, and creates a build directory if one does not exist.
1941For example, on a Sun system running Solaris 8, the directory
9b371988
PH
1942&_build-SunOS5-5.8-sparc_& is created.
1943.cindex "symbolic link" "to source files"
168e428f
PH
1944Symbolic links to relevant source files are installed in the build directory.
1945
9b371988 1946&*Warning*&: The &%-j%& (parallel) flag must not be used with &'make'&; the
168e428f
PH
1947building process fails if it is set.
1948
9b371988 1949If this is the first time &'make'& has been run, it calls a script that builds
168e428f 1950a make file inside the build directory, using the configuration files from the
9b371988
PH
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
168e428f 1953then compiling and linking the binaries for the Exim monitor (if configured), a
9b371988
PH
1954number of utility programs, and finally Exim itself. The command &`make
1955makefile`& can be used to force a rebuild of the make file in the build
168e428f
PH
1956directory, should this ever be necessary.
1957
1958If you have problems building Exim, check for any comments there may be in the
9b371988 1959&_README_& file concerning your operating system, and also take a look at the
168e428f
PH
1960FAQ, where some common problems are covered.
1961
1962
1963
f89d2485 1964.section 'Output from &"make"&' "SECID283"
9b371988 1965The output produced by the &'make'& process for compile lines is often very
068aaea8
PH
1966unreadable, because these lines can be very long. For this reason, the normal
1967output is suppressed by default, and instead output similar to that which
1968appears when compiling the 2.6 Linux kernel is generated: just a short line for
1969each module that is being compiled or linked. However, it is still possible to
9b371988
PH
1970get the full output, by calling &'make'& like this:
1971.code
1972FULLECHO='' make -e
1973.endd
1974The value of FULLECHO defaults to &"@"&, the flag character that suppresses
1975command reflection in &'make'&. When you ask for the full output, it is
3cb1b51e 1976given in addition to the short output.
068aaea8
PH
1977
1978
1979
9b371988 1980.section "Overriding build-time options for Exim" "SECToverride"
f89d2485 1981.cindex "build-time options, overriding"
168e428f
PH
1982The main make file that is created at the beginning of the building process
1983consists of the concatenation of a number of files which set configuration
9b371988 1984values, followed by a fixed set of &'make'& instructions. If a value is set
168e428f
PH
1985more than once, the last setting overrides any previous ones. This provides a
1986convenient way of overriding defaults. The files that are concatenated are, in
1987order:
9b371988
PH
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"
2000where <&'ostype'&> is the operating system type and <&'archtype'&> is the
2001architecture type. &_Local/Makefile_& is required to exist, and the building
2002process fails if it is absent. The other three &_Local_& files are optional,
168e428f
PH
2003and are often not needed.
2004
9b371988
PH
2005The values used for <&'ostype'&> and <&'archtype'&> are obtained from scripts
2006called &_scripts/os-type_& and &_scripts/arch-type_& respectively. If either of
168e428f
PH
2007the environment variables EXIM_OSTYPE or EXIM_ARCHTYPE is set, their
2008values are used, thereby providing a means of forcing particular settings.
9b371988 2009Otherwise, the scripts try to get values from the &%uname%& command. If this
168e428f 2010fails, the shell variables OSTYPE and ARCHTYPE are inspected. A number
9b371988 2011of &'ad hoc'& transformations are then applied, to produce the standard names
168e428f
PH
2012that Exim expects. You can run these scripts directly from the shell in order
2013to find out what values are being used on your system.
2014
2015
9b371988 2016&_OS/Makefile-Default_& contains comments about the variables that are set
168e428f
PH
2017therein. Some (but not all) are mentioned below. If there is something that
2018needs changing, review the contents of this file and the contents of the make
9b371988 2019file for your operating system (&_OS/Makefile-<ostype>_&) to see what the
168e428f
PH
2020default values are.
2021
2022
9b371988
PH
2023.cindex "building Exim" "overriding default settings"
2024If you need to change any of the values that are set in &_OS/Makefile-Default_&
2025or in &_OS/Makefile-<ostype>_&, or to add any new definitions, you do not
168e428f 2026need to change the original files. Instead, you should make the changes by
9b371988
PH
2027putting the new values in an appropriate &_Local_& file. For example,
2028.cindex "Tru64-Unix build-time settings"
168e428f
PH
2029when building Exim in many releases of the Tru64-Unix (formerly Digital UNIX,
2030formerly DEC-OSF1) operating system, it is necessary to specify that the C
9b371988
PH
2031compiler is called &'cc'& rather than &'gcc'&. Also, the compiler must be
2032called with the option &%-std1%&, to make it recognize some of the features of
168e428f 2033Standard C that Exim uses. (Most other compilers recognize Standard C by
9b371988 2034default.) To do this, you should create a file called &_Local/Makefile-OSF1_&
168e428f 2035containing the lines
9b371988
PH
2036.code
2037CC=cc
2038CFLAGS=-std1
2039.endd
168e428f 2040If you are compiling for just one operating system, it may be easier to put
9b371988 2041these lines directly into &_Local/Makefile_&.
168e428f
PH
2042
2043Keeping all your local configuration settings separate from the distributed
2044files makes it easy to transfer them to new versions of Exim simply by copying
9b371988 2045the contents of the &_Local_& directory.
168e428f
PH
2046
2047
9b371988
PH
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"
168e428f
PH
2052Exim contains support for doing LDAP, NIS, NIS+, and other kinds of file
2053lookup, but not all systems have these components installed, so the default is
2054not to include the relevant code in the binary. All the different kinds of file
2055and database lookup that Exim supports are implemented as separate code modules
2056which are included only if the relevant compile-time options are set. In the
9b371988
PH
2057case of LDAP, NIS, and NIS+, the settings for &_Local/Makefile_& are:
2058.code
2059LOOKUP_LDAP=yes
2060LOOKUP_NIS=yes
2061LOOKUP_NISPLUS=yes
2062.endd
168e428f 2063and similar settings apply to the other lookup types. They are all listed in
9b371988 2064&_src/EDITME_&. In many cases the relevant include files and interface
168e428f 2065libraries need to be installed before compiling Exim.
9b371988 2066.cindex "cdb" "including support for"
068aaea8
PH
2067However, there are some optional lookup types (such as cdb) for which
2068the code is entirely contained within Exim, and no external include
168e428f
PH
2069files or libraries are required. When a lookup type is not included in the
2070binary, attempts to configure Exim to use it cause run time configuration
2071errors.
2072
9b371988 2073.cindex "Perl" "including support for"
168e428f
PH
2074Exim can be linked with an embedded Perl interpreter, allowing Perl
2075subroutines to be called during string expansion. To enable this facility,
9b371988
PH
2076.code
2077EXIM_PERL=perl.o
2078.endd
2079must be defined in &_Local/Makefile_&. Details of this facility are given in
2080chapter &<<CHAPperl>>&.
168e428f 2081
f89d2485 2082.cindex "X11 libraries, location of"
168e428f 2083The location of the X11 libraries is something that varies a lot between
068aaea8 2084operating systems, and there may be different versions of X11 to cope
168e428f
PH
2085with. Exim itself makes no use of X11, but if you are compiling the Exim
2086monitor, the X11 libraries must be available.
9b371988
PH
2087The following three variables are set in &_OS/Makefile-Default_&:
2088.code
2089X11=/usr/X11R6
2090XINCLUDE=-I$(X11)/include
2091XLFLAGS=-L$(X11)/lib
2092.endd
168e428f 2093These are overridden in some of the operating-system configuration files. For
9b371988
PH
2094example, in &_OS/Makefile-SunOS5_& there is
2095.code
2096X11=/usr/openwin
2097XINCLUDE=-I$(X11)/include
2098XLFLAGS=-L$(X11)/lib -R$(X11)/lib
2099.endd
168e428f
PH
2100If you need to override the default setting for your operating system, place a
2101definition of all three of these variables into your
9b371988 2102&_Local/Makefile-<ostype>_& file.
168e428f 2103
9b371988 2104.cindex "EXTRALIBS"
168e428f
PH
2105If you need to add any extra libraries to the link steps, these can be put in a
2106variable called EXTRALIBS, which appears in all the link commands, but by
2107default is not defined. In contrast, EXTRALIBS_EXIM is used only on the
2108command for linking the main Exim binary, and not for any associated utilities.
2109
9b371988 2110.cindex "DBM libraries" "configuration for building"
168e428f 2111There is also DBMLIB, which appears in the link commands for binaries that
9b371988 2112use DBM functions (see also section &<<SECTdb>>&). Finally, there is
168e428f
PH
2113EXTRALIBS_EXIMON, which appears only in the link step for the Exim monitor
2114binary, and which can be used, for example, to include additional X11
2115libraries.
2116
9b371988 2117.cindex "configuration file" "editing"
168e428f
PH
2118The make file copes with rebuilding Exim correctly if any of the configuration
2119files are edited. However, if an optional configuration file is deleted, it is
9b371988
PH
2120necessary to touch the associated non-optional file (that is,
2121&_Local/Makefile_& or &_Local/eximon.conf_&) before rebuilding.
168e428f
PH
2122
2123
f89d2485 2124.section "OS-specific header files" "SECID30"
9b371988
PH
2125.cindex "&_os.h_&"
2126.cindex "building Exim" "OS-specific C header files"
2127The &_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
168e428f 2129normally need to be changed. There is a list of macro settings that are
9b371988 2130recognized in the file &_OS/os.configuring_&, which should be consulted if you
168e428f
PH
2131are porting Exim to a new operating system.
2132
2133
2134
f89d2485
PH
2135.section "Overriding build-time options for the monitor" "SECID31"
2136.cindex "building Eximon"
168e428f
PH
2137A similar process is used for overriding things when building the Exim monitor,
2138where the files that are involved are
9b371988
PH
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_&"
168e428f 2148As with Exim itself, the final three files need not exist, and in this case the
9b371988
PH
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
168e428f
PH
2151variables of the same name, preceded by EXIMON_. For example, setting
2152EXIMON_LOG_DEPTH in the environment overrides the value of
2153LOG_DEPTH at run time.
4f578862 2154.ecindex IIDbuex
168e428f
PH
2155
2156
f89d2485 2157.section "Installing Exim binaries and scripts" "SECID32"
9b371988
PH
2158.cindex "installing Exim"
2159.cindex "BIN_DIRECTORY"
2160The command &`make install`& runs the &(exim_install)& script with no
2161arguments. The script copies binaries and utility scripts into the directory
2162whose name is specified by the BIN_DIRECTORY setting in &_Local/Makefile_&.
2163.cindex "setuid" "installing Exim with"
068aaea8
PH
2164The install script copies files only if they are newer than the files they are
2165going to replace. The Exim binary is required to be owned by root and have the
9b371988
PH
2166&'setuid'& bit set, for normal configurations. Therefore, you must run &`make
2167install`& as root so that it can set up the Exim binary in this way. However, in
068aaea8
PH
2168some special situations (for example, if a host is doing no local deliveries)
2169it may be possible to run Exim without making the binary setuid root (see
9b371988 2170chapter &<<CHAPsecurity>>& for details).
168e428f 2171
9b371988 2172.cindex "CONFIGURE_FILE"
168e428f 2173Exim's run time configuration file is named by the CONFIGURE_FILE setting
9b371988
PH
2174in &_Local/Makefile_&. If this names a single file, and the file does not
2175exist, the default configuration file &_src/configure.default_& is copied there
168e428f
PH
2176by the installation script. If a run time configuration file already exists, it
2177is left alone. If CONFIGURE_FILE is a colon-separated list, naming several
2178alternative files, no default is installed.
2179
9b371988
PH
2180.cindex "system aliases file"
2181.cindex "&_/etc/aliases_&"
168e428f
PH
2182One change is made to the default configuration file when it is installed: the
2183default configuration contains a router that references a system aliases file.
2184The path to this file is set to the value specified by
9b371988 2185SYSTEM_ALIASES_FILE in &_Local/Makefile_& (&_/etc/aliases_& by default).
168e428f
PH
2186If the system aliases file does not exist, the installation script creates it,
2187and outputs a comment to the user.
2188
2189The created file contains no aliases, but it does contain comments about the
2190aliases a site should normally have. Mail aliases have traditionally been
9b371988
PH
2191kept 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
168e428f
PH
2193Exim's configuration if necessary.
2194
2195The default configuration uses the local host's name as the only local domain,
9b371988
PH
2196and is set up to do local deliveries into the shared directory &_/var/mail_&,
2197running as the local user. System aliases and &_.forward_& files in users' home
168e428f
PH
2198directories are supported, but no NIS or NIS+ support is configured. Domains
2199other than the name of the local host are routed using the DNS, with delivery
2200over SMTP.
2201
168e428f
PH
2202It is possible to install Exim for special purposes (such as building a binary
2203distribution) in a private part of the file system. You can do this by a
2204command such as
9b371988
PH
2205.code
2206make DESTDIR=/some/directory/ install
2207.endd
168e428f
PH
2208This has the effect of pre-pending the specified directory to all the file
2209paths, except the name of the system aliases file that appears in the default
9b371988 2210configuration. (If a default alias file is created, its name &'is'& modified.)
168e428f
PH
2211For backwards compatibility, ROOT is used if DESTDIR is not set,
2212but this usage is deprecated.
2213
9b371988
PH
2214.cindex "installing Exim" "what is not installed"
2215Running &'make install'& does not copy the Exim 4 conversion script
2216&'convert4r4'&, or the &'pcretest'& test program. You will probably run the
168e428f 2217first of these only once (if you are upgrading from Exim 3), and the second
9b371988 2218isn't really part of Exim. None of the documentation files in the &_doc_&
168e428f 2219directory are copied, except for the info files when you have set
9b371988 2220INFO_DIRECTORY, as described in section &<<SECTinsinfdoc>>& below.
168e428f 2221
9b371988 2222For the utility programs, old versions are renamed by adding the suffix &_.O_&
168e428f
PH
2223to their names. The Exim binary itself, however, is handled differently. It is
2224installed under a name that includes the version number and the compile number,
9b371988
PH
2225for example &_exim-&version;-1_&. The script then arranges for a symbolic link
2226called &_exim_& to point to the binary. If you are updating a previous version
2227of Exim, the script takes care to ensure that the name &_exim_& is never absent
168e428f
PH
2228from the directory (as seen by other processes).
2229
9b371988
PH
2230.cindex "installing Exim" "testing the script"
2231If you want to see what the &'make install'& will do before running it for
2232real, you can pass the &%-n%& option to the installation script by this
2233command:
2234.code
2235make INSTALL_ARG=-n install
2236.endd
168e428f
PH
2237The contents of the variable INSTALL_ARG are passed to the installation
2238script. You do not need to be root to run this test. Alternatively, you can run
2239the installation script directly, but this must be from within the build
2240directory. For example, from the top-level Exim directory you could use this
2241command:
9b371988
PH
2242.code
2243(cd build-SunOS5-5.5.1-sparc; ../scripts/exim_install -n)
2244.endd
2245.cindex "installing Exim" "install script options"
168e428f
PH
2246There are two other options that can be supplied to the installation script.
2247
9b371988
PH
2248.ilist
2249&%-no_chown%& bypasses the call to change the owner of the installed binary
168e428f 2250to root, and the call to make it a setuid binary.
9b371988
PH
2251.next
2252&%-no_symlink%& bypasses the setting up of the symbolic link &_exim_& to the
168e428f 2253installed binary.
9b371988 2254.endlist
168e428f
PH
2255
2256INSTALL_ARG can be used to pass these options to the script. For example:
9b371988
PH
2257.code
2258make INSTALL_ARG=-no_symlink install
2259.endd
168e428f
PH
2260The installation script can also be given arguments specifying which files are
2261to be copied. For example, to install just the Exim binary, and nothing else,
2262without creating the symbolic link, you could use:
9b371988
PH
2263.code
2264make INSTALL_ARG='-no_symlink exim' install
2265.endd
168e428f
PH
2266
2267
2268
9b371988
PH
2269.section "Installing info documentation" "SECTinsinfdoc"
2270.cindex "installing Exim" "&'info'& documentation"
2271Not all systems use the GNU &'info'& system for documentation, and for this
168e428f
PH
2272reason, the Texinfo source of Exim's documentation is not included in the main
2273distribution. Instead it is available separately from the ftp site (see section
9b371988 2274&<<SECTavail>>&).
168e428f 2275
9b371988
PH
2276If you have defined INFO_DIRECTORY in &_Local/Makefile_& and the Texinfo
2277source of the documentation is found in the source tree, running &`make
2278install`& automatically builds the info files and installs them.
168e428f
PH
2279
2280
2281
f89d2485 2282.section "Setting up the spool directory" "SECID33"
9b371988 2283.cindex "spool directory" "creating"
168e428f
PH
2284When it starts up, Exim tries to create its spool directory if it does not
2285exist. The Exim uid and gid are used for the owner and group of the spool
2286directory. Sub-directories are automatically created in the spool directory as
2287necessary.
2288
2289
2290
2291
f89d2485 2292.section "Testing" "SECID34"
9b371988 2293.cindex "testing" "installation"
168e428f
PH
2294Having installed Exim, you can check that the run time configuration file is
2295syntactically valid by running the following command, which assumes that the
2296Exim binary directory is within your PATH environment variable:
9b371988
PH
2297.code
2298exim -bV
2299.endd
168e428f
PH
2300If there are any errors in the configuration file, Exim outputs error messages.
2301Otherwise it outputs the version number and build date,
2302the DBM library that is being used, and information about which drivers and
2303other optional code modules are included in the binary.
2304Some simple routing tests can be done by using the address testing option. For
2305example,
9b371988
PH
2306.display
2307&`exim -bt`& <&'local username'&>
2308.endd
168e428f 2309should verify that it recognizes a local mailbox, and
9b371988
PH
2310.display
2311&`exim -bt`& <&'remote address'&>
2312.endd
168e428f
PH
2313a remote one. Then try getting it to deliver mail, both locally and remotely.
2314This can be done by passing messages directly to Exim, without going through a
2315user agent. For example:
9b371988 2316.code
068aaea8
PH
2317exim -v postmaster@your.domain.example
2318From: user@your.domain.example
2319To: postmaster@your.domain.example
2320Subject: Testing Exim
168e428f 2321
068aaea8
PH
2322This is a test message.
2323^D
9b371988
PH
2324.endd
2325The &%-v%& option causes Exim to output some verification of what it is doing.
168e428f 2326In this case you should see copies of three log lines, one for the message's
9b371988 2327arrival, one for its delivery, and one containing &"Completed"&.
168e428f 2328
9b371988
PH
2329.cindex "delivery" "problems with"
2330If you encounter problems, look at Exim's log files (&'mainlog'& and
2331&'paniclog'&) to see if there is any relevant information there. Another source
168e428f 2332of information is running Exim with debugging turned on, by specifying the
9b371988 2333&%-d%& option. If a message is stuck on Exim's spool, you can force a delivery
168e428f 2334with debugging turned on by a command of the form
9b371988
PH
2335.display
2336&`exim -d -M`& <&'exim-message-id'&>
2337.endd
2338You must be root or an &"admin user"& in order to do this. The &%-d%& option
168e428f 2339produces rather a lot of output, but you can cut this down to specific areas.
9b371988
PH
2340For example, if you use &%-d-all+route%& only the debugging information
2341relevant to routing is included. (See the &%-d%& option in chapter
2342&<<CHAPcommandline>>& for more details.)
168e428f 2343
9b371988
PH
2344.cindex '&"sticky"& bit'
2345.cindex "lock files"
168e428f
PH
2346One specific problem that has shown up on some sites is the inability to do
2347local deliveries into a shared mailbox directory, because it does not have the
9b371988 2348&"sticky bit"& set on it. By default, Exim tries to create a lock file before
168e428f 2349writing to a mailbox file, and if it cannot create the lock file, the delivery
9b371988 2350is deferred. You can get round this either by setting the &"sticky bit"& on the
168e428f
PH
2351directory, or by setting a specific group for local deliveries and allowing
2352that group to create files in the directory (see the comments above the
9b371988 2353&(local_delivery)& transport in the default configuration file). Another
168e428f 2354approach is to configure Exim not to use lock files, but just to rely on
9b371988
PH
2355&[fcntl()]& locking instead. However, you should do this only if all user
2356agents also use &[fcntl()]& locking. For further discussion of locking issues,
2357see chapter &<<CHAPappendfile>>&.
168e428f
PH
2358
2359One thing that cannot be tested on a system that is already running an MTA is
2360the receipt of incoming SMTP mail on the standard SMTP port. However, the
9b371988
PH
2361&%-oX%& option can be used to run an Exim daemon that listens on some other
2362port, 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
168e428f
PH
2364incoming SMTP mail.
2365
2366Testing a new version on a system that is already running Exim can most easily
2367be done by building a binary with a different CONFIGURE_FILE setting. From
2368within the run time configuration, all other file and directory names
2369that Exim uses can be altered, in order to keep it entirely clear of the
2370production version.
2371
2372
f89d2485 2373.section "Replacing another MTA with Exim" "SECID35"
9b371988 2374.cindex "replacing another MTA"
168e428f
PH
2375Building and installing Exim for the first time does not of itself put it in
2376general use. The name by which the system's MTA is called by mail user agents
9b371988
PH
2377is either &_/usr/sbin/sendmail_&, or &_/usr/lib/sendmail_& (depending on the
2378operating system), and it is necessary to make this name point to the &'exim'&
168e428f 2379binary in order to get the user agents to pass messages to Exim. This is
9b371988
PH
2380normally done by renaming any existing file and making &_/usr/sbin/sendmail_&
2381or &_/usr/lib/sendmail_&
2382.cindex "symbolic link" "to &'exim'& binary"
2383a symbolic link to the &'exim'& binary. It is a good idea to remove any setuid
168e428f
PH
2384privilege and executable status from the old MTA. It is then necessary to stop
2385and restart the mailer daemon, if one is running.
2386
f89d2485 2387.cindex "FreeBSD, MTA indirection"
9b371988 2388.cindex "&_/etc/mail/mailer.conf_&"
168e428f
PH
2389Some operating systems have introduced alternative ways of switching MTAs. For
2390example, if you are running FreeBSD, you need to edit the file
9b371988 2391&_/etc/mail/mailer.conf_& instead of setting up a symbolic link as just
168e428f
PH
2392described. A typical example of the contents of this file for running Exim is
2393as follows:
9b371988
PH
2394.code
2395sendmail /usr/exim/bin/exim
2396send-mail /usr/exim/bin/exim
2397mailq /usr/exim/bin/exim -bp
2398newaliases /usr/bin/true
2399.endd
2400Once you have set up the symbolic link, or edited &_/etc/mail/mailer.conf_&,
2401your Exim installation is &"live"&. Check it by sending a message from your
168e428f
PH
2402favourite user agent.
2403
2404You should consider what to tell your users about the change of MTA. Exim may
2405have different capabilities to what was previously running, and there are
2406various operational differences such as the text of messages produced by
2407command line options and in bounce messages. If you allow your users to make
2408use of Exim's filtering capabilities, you should make the document entitled
9b371988 2409&'Exim's interface to mail filtering'& available to them.
168e428f
PH
2410
2411
2412
f89d2485 2413.section "Upgrading Exim" "SECID36"
9b371988 2414.cindex "upgrading Exim"
168e428f
PH
2415If you are already running Exim on your host, building and installing a new
2416version automatically makes it available to MUAs, or any other programs that
2417call the MTA directly. However, if you are running an Exim daemon, you do need
9b371988
PH
2418to send it a HUP signal, to make it re-execute itself, and thereby pick up the
2419new binary. You do not need to stop processing mail in order to install a new
068aaea8
PH
2420version of Exim. The install script does not modify an existing runtime
2421configuration file.
2422
168e428f
PH
2423
2424
2425
f89d2485 2426.section "Stopping the Exim daemon on Solaris" "SECID37"
9b371988 2427.cindex "Solaris" "stopping Exim on"
168e428f 2428The standard command for stopping the mailer daemon on Solaris is
9b371988
PH
2429.code
2430/etc/init.d/sendmail stop
2431.endd
2432If &_/usr/lib/sendmail_& has been turned into a symbolic link, this script
2433fails to stop Exim because it uses the command &'ps -e'& and greps the output
2434for 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
2436solution is to replace the line that finds the process id with something like
2437.code
2438pid=`cat /var/spool/exim/exim-daemon.pid`
2439.endd
168e428f
PH
2440to obtain the daemon's pid directly from the file that Exim saves it in.
2441
9b371988 2442Note, however, that stopping the daemon does not &"stop Exim"&. Messages can
168e428f
PH
2443still be received from local processes, and if automatic delivery is configured
2444(the normal case), deliveries will still occur.
2445
2446
2447
2448
9b371988
PH
2449. ////////////////////////////////////////////////////////////////////////////
2450. ////////////////////////////////////////////////////////////////////////////
168e428f 2451
9b371988 2452.chapter "The Exim command line" "CHAPcommandline"
4f578862
PH
2453.scindex IIDclo1 "command line" "options"
2454.scindex IIDclo2 "options" "command line"
168e428f
PH
2455Exim's command line takes the standard Unix form of a sequence of options,
2456each starting with a hyphen character, followed by a number of arguments. The
2457options are compatible with the main options of Sendmail, and there are also
2458some additional options, some of which are compatible with Smail 3. Certain
2459combinations of options do not make sense, and provoke an error if used.
2460The form of the arguments depends on which options are set.
2461
2462
f89d2485 2463.section "Setting options by program name" "SECID38"
9b371988
PH
2464.cindex "&'mailq'&"
2465If Exim is called under the name &'mailq'&, it behaves as if the option &%-bp%&
168e428f 2466were present before any other options.
9b371988 2467The &%-bp%& option requests a listing of the contents of the mail queue on the
168e428f
PH
2468standard output.
2469This feature is for compatibility with some systems that contain a command of
2470that name in one of the standard libraries, symbolically linked to
9b371988
PH
2471&_/usr/sbin/sendmail_& or &_/usr/lib/sendmail_&.
2472
2473.cindex "&'rsmtp'&"
2474If Exim is called under the name &'rsmtp'& it behaves as if the option &%-bS%&
2475were 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
2477format.
2478
2479.cindex "&'rmail'&"
2480If 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
2482Smail. The name &'rmail'& is used as an interface by some UUCP systems.
2483
2484.cindex "&'runq'&"
2485.cindex "queue runner"
2486If Exim is called under the name &'runq'& it behaves as if the option &%-q%&
2487were present before any other options, for compatibility with Smail. The &%-q%&
168e428f
PH
2488option causes a single queue runner process to be started.
2489
9b371988
PH
2490.cindex "&'newaliases'&"
2491.cindex "alias file" "building"
2492.cindex "Sendmail compatibility" "calling Exim as &'newaliases'&"
2493If 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.
168e428f
PH
2495This option is used for rebuilding Sendmail's alias file. Exim does not have
2496the concept of a single alias file, but can be configured to run a given
9b371988 2497command if called with the &%-bi%& option.
168e428f
PH
2498
2499
9b371988
PH
2500.section "Trusted and admin users" "SECTtrustedadmin"
2501Some Exim options are available only to &'trusted users'& and others are
2502available only to &'admin users'&. In the description below, the phrases &"Exim
2503user"& and &"Exim group"& mean the user and group defined by EXIM_USER and
2504EXIM_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"&.
168e428f 2506
9b371988 2507.ilist
f89d2485 2508.cindex "trusted users" "definition of"
9b371988 2509.cindex "user" "trusted definition of"
168e428f 2510The trusted users are root, the Exim user, any user listed in the
9b371988
PH
2511&%trusted_users%& configuration option, and any user whose current group or any
2512supplementary group is one of those listed in the &%trusted_groups%&
168e428f 2513configuration option. Note that the Exim group is not automatically trusted.
9b371988
PH
2514
2515.cindex '&"From"& line'
2516.cindex "envelope sender"
2517Trusted 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
2519Exim through the local interface (see the &%-bm%& and &%-f%& options below).
2520See the &%untrusted_set_sender%& option for a way of permitting non-trusted
2521users to set envelope senders.
2522
2523.cindex "&'From:'& header line"
2524.cindex "&'Sender:'& header line"
2525For a trusted user, there is never any check on the contents of the &'From:'&
2526header line, and a &'Sender:'& line is never added. Furthermore, any existing
2527&'Sender:'& line in incoming local (non-TCP/IP) messages is not removed.
2528
168e428f
PH
2529Trusted users may also specify a host name, host address, interface address,
2530protocol name, ident value, and authentication data when submitting a message
2531locally. Thus, they are able to insert messages into Exim's queue locally that
2532have the characteristics of messages received from a remote host. Untrusted
9b371988 2533users may in some circumstances use &%-f%&, but can never set the other values
168e428f 2534that are available to trusted users.
9b371988
PH
2535.next
2536.cindex "user" "admin definition of"
2537.cindex "admin user" "definition of"
168e428f 2538The admin users are root, the Exim user, and any user that is a member of the
9b371988 2539Exim group or of any group listed in the &%admin_groups%& configuration option.
168e428f 2540The current group does not have to be one of these groups.
9b371988 2541
168e428f
PH
2542Admin users are permitted to list the queue, and to carry out certain
2543operations on messages, for example, to force delivery failures. It is also
2544necessary to be an admin user in order to see the full information provided by
2545the Exim monitor, and full debugging output.
9b371988
PH
2546
2547By default, the use of the &%-M%&, &%-q%&, &%-R%&, and &%-S%& options to cause
2548Exim to attempt delivery of messages on its queue is restricted to admin users.
2549However, this restriction can be relaxed by setting the &%prod_requires_admin%&
2550option false (that is, specifying &%no_prod_requires_admin%&).
2551
2552Similarly, the use of the &%-bp%& option to list all the messages in the queue
2553is restricted to admin users unless &%queue_list_requires_admin%& is set
168e428f 2554false.
9b371988 2555.endlist
168e428f
PH
2556
2557
9b371988 2558&*Warning*&: If you configure your system so that admin users are able to
168e428f
PH
2559edit Exim's configuration file, you are giving those users an easy way of
2560getting root. There is further discussion of this issue at the start of chapter
9b371988 2561&<<CHAPconf>>&.
168e428f
PH
2562
2563
2564
2565
f89d2485 2566.section "Command line options" "SECID39"
db9452a9
PH
2567Exim's command line options are described in alphabetical order below. If none
2568of the options that specifies a specific action (such as starting the daemon or
2569a queue runner, or testing an address, or receiving a message in a specific
2570format, or listing the queue) are present, and there is at least one argument
2571on the command line, &%-bm%& (accept a local message on the standard input,
2572with the arguments specifying the recipients) is assumed. Otherwise, Exim
2573outputs a brief message about itself and exits.
168e428f 2574
9b371988
PH
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. ////////////////////////////////////////////////////////////////////////////
168e428f 2580
9b371988 2581.literal xml
168e428f 2582<!-- === Start of command line options === -->
9b371988 2583.literal off
168e428f
PH
2584
2585
9b371988
PH
2586.vlist
2587.vitem &%--%&
2588.oindex "--"
2589.cindex "options" "command line; terminating"
168e428f
PH
2590This is a pseudo-option whose only purpose is to terminate the options and
2591therefore to cause subsequent command line items to be treated as arguments
2592rather than options, even if they begin with hyphens.
2593
9b371988
PH
2594.vitem &%--help%&
2595.oindex "&%--help%&"
168e428f
PH
2596This option causes Exim to output a few sentences stating what it is.
2597The same output is generated if the Exim binary is called with no options and
2598no arguments.
2599
9b371988
PH
2600.vitem &%-B%&<&'type'&>
2601.oindex "&%-B%&"
2602.cindex "8-bit characters"
2603.cindex "Sendmail compatibility" "8-bit characters"
168e428f
PH
2604This is a Sendmail option for selecting 7 or 8 bit processing. Exim is 8-bit
2605clean; it ignores this option.
2606
9b371988
PH
2607.vitem &%-bd%&
2608.oindex "&%-bd%&"
2609.cindex "daemon"
f89d2485 2610.cindex "SMTP" "listener"
9b371988 2611.cindex "queue runner"
168e428f 2612This option runs Exim as a daemon, awaiting incoming SMTP connections. Usually
9b371988
PH
2613the &%-bd%& option is combined with the &%-q%&<&'time'&> option, to specify
2614that the daemon should also initiate periodic queue runs.
2615
2616The &%-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
168e428f
PH
2618disconnect from the controlling terminal. When running this way, it can be
2619stopped by pressing ctrl-C.
9b371988 2620
168e428f
PH
2621By default, Exim listens for incoming connections to the standard SMTP port on
2622all the host's running interfaces. However, it is possible to listen on other
2623ports, on multiple ports, and only on specific interfaces. Chapter
9b371988
PH
2624&<<CHAPinterfaces>>& contains a description of the options that control this.
2625
168e428f 2626When a listening daemon
9b371988
PH
2627.cindex "daemon" "process id (pid)"
2628.cindex "pid (process id)" "of daemon"
2629is started without the use of &%-oX%& (that is, without overriding the normal
2630configuration), it writes its process id to a file called &_exim-daemon.pid_&
2631in Exim's spool directory. This location can be overridden by setting
2632PID_FILE_PATH in &_Local/Makefile_&. The file is written while Exim is still
168e428f 2633running as root.
9b371988
PH
2634
2635When &%-oX%& is used on the command line to start a listening daemon, the
2636process id is not written to the normal pid file path. However, &%-oP%& can be
168e428f 2637used to specify a path on the command line if a pid file is required.
9b371988 2638
168e428f 2639The SIGHUP signal
9b371988 2640.cindex "SIGHUP"
3cb1b51e
PH
2641.cindex "daemon" "restarting"
2642can be used to cause the daemon to re-execute itself. This should be done
2643whenever Exim's configuration file, or any file that is incorporated into it by
2644means of the &%.include%& facility, is changed, and also whenever a new version
2645of Exim is installed. It is not necessary to do this when other files that are
9b371988
PH
2646referenced from the configuration (for example, alias files) are changed,
2647because these are reread each time they are used.
2648
2649.vitem &%-bdf%&
2650.oindex "&%-bdf%&"
2651This option has the same effect as &%-bd%& except that it never disconnects
2652from the controlling terminal, even when no debugging is specified.
2653
2654.vitem &%-be%&
2655.oindex "&%-be%&"
2656.cindex "testing" "string expansion"
2657.cindex "expansion" "testing"
168e428f
PH
2658Run Exim in expansion testing mode. Exim discards its root privilege, to
2659prevent ordinary users from using this mode to read otherwise inaccessible
2660files. If no arguments are given, Exim runs interactively, prompting for lines
4f578862 2661of data. Otherwise, it processes each argument in turn.
9b371988
PH
2662
2663If Exim was built with USE_READLINE=yes in &_Local/Makefile_&, it tries
2664to load the &%libreadline%& library dynamically whenever the &%-be%& option is
2665used without command line arguments. If successful, it uses the &[readline()]&
168e428f
PH
2666function, which provides extensive line-editing facilities, for reading the
2667test data. A line history is supported.
9b371988 2668
168e428f 2669Long expansion expressions can be split over several lines by using backslash
068aaea8 2670continuations. As in Exim's run time configuration, white space at the start of
168e428f
PH
2671continuation lines is ignored. Each argument or data line is passed through the
2672string expansion mechanism, and the result is output. Variable values from the
9b371988 2673configuration file (for example, &$qualify_domain$&) are available, but no
3cb1b51e 2674message-specific values (such as &$sender_domain$&) are set, because no message
f89d2485 2675is being processed (but see &%-bem%& and &%-Mset%&).
168e428f 2676
9b371988
PH
2677&*Note*&: If you use this mechanism to test lookups, and you change the data
2678files or databases you are using, you must exit and restart Exim before trying
2679the same lookup again. Otherwise, because each Exim process caches the results
2680of lookups, you will just get the same result as before.
9b371988 2681
3cb1b51e
PH
2682.vitem &%-bem%&&~<&'filename'&>
2683.oindex "&%-bem%&"
2684.cindex "testing" "string expansion"
2685.cindex "expansion" "testing"
2686This option operates like &%-be%& except that it must be followed by the name
2687of a file. For example:
2688.code
2689exim -bem /tmp/testmessage
2690.endd
2691The file is read as a message (as if receiving a locally-submitted non-SMTP
2692message) before any of the test expansions are done. Thus, message-specific
2693variables such as &$message_size$& and &$header_from:$& are available. However,
2694no &'Received:'& header is added to the message. If the &%-t%& option is set,
2695recipients are read from the headers in the normal way, and are shown in the
2696&$recipients$& variable. Note that recipients cannot be given on the command
2697line, because further arguments are taken as strings to expand (just like
2698&%-be%&).
3cb1b51e 2699
9b371988
PH
2700.vitem &%-bF%&&~<&'filename'&>
2701.oindex "&%-bF%&"
2702.cindex "system filter" "testing"
2703.cindex "testing" "system filter"
2704This option is the same as &%-bf%& except that it assumes that the filter being
168e428f
PH
2705tested is a system filter. The additional commands that are available only in
2706system filters are recognized.
2707
9b371988
PH
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"
168e428f
PH
2715This option runs Exim in user filter testing mode; the file is the filter file
2716to be tested, and a test message must be supplied on the standard input. If
2717there are no message-dependent tests in the filter, an empty file can be
2718supplied.
168e428f 2719
9b371988
PH
2720If you want to test a system filter file, use &%-bF%& instead of &%-bf%&. You
2721can use both &%-bF%& and &%-bf%& on the same command, in order to test a system
2722filter and a user filter in the same run. For example:
2723.code
2724exim -bF /system/filter -bf /user/filter </test/message
2725.endd
168e428f
PH
2726This is helpful when the system filter adds header lines or sets filter
2727variables that are used by the user filter.
168e428f 2728
9b371988
PH
2729If the test filter file does not begin with one of the special lines
2730.code
2731# Exim filter
2732# Sieve filter
2733.endd
2734it is taken to be a normal &_.forward_& file, and is tested for validity under
2735that interpretation. See sections &<<SECTitenonfilred>>& to
2736&<<SECTspecitredli>>& for a description of the possible contents of non-filter
2737redirection lists.
2738
2739The result of an Exim command that uses &%-bf%&, provided no errors are
168e428f
PH
2740detected, is a list of the actions that Exim would try to take if presented
2741with the message for real. More details of filter testing are given in the
9b371988
PH
2742separate document entitled &'Exim's interfaces to mail filtering'&.
2743
168e428f 2744When testing a filter file,
9b371988
PH
2745.cindex "&""From""& line"
2746.cindex "envelope sender"
f89d2485 2747.oindex "&%-f%&" "for filter testing"
9b371988
PH
2748the envelope sender can be set by the &%-f%& option,
2749or by a &"From&~"& line at the start of the test message. Various parameters
2750that would normally be taken from the envelope recipient address of the message
2751can be set by means of additional command line options (see the next four
2752options).
2753
2754.vitem &%-bfd%&&~<&'domain'&>
2755.oindex "&%-bfd%&"
f89d2485 2756.vindex "&$qualify_domain$&"
168e428f 2757This sets the domain of the recipient address when a filter file is being
9b371988
PH
2758tested by means of the &%-bf%& option. The default is the value of
2759&$qualify_domain$&.
168e428f 2760
9b371988
PH
2761.vitem &%-bfl%&&~<&'local&~part'&>
2762.oindex "&%-bfl%&"
168e428f 2763This sets the local part of the recipient address when a filter file is being
9b371988 2764tested by means of the &%-bf%& option. The default is the username of the
168e428f
PH
2765process that calls Exim. A local part should be specified with any prefix or
2766suffix stripped, because that is how it appears to the filter when a message is
2767actually being delivered.
2768
9b371988
PH
2769.vitem &%-bfp%&&~<&'prefix'&>
2770.oindex "&%-bfp%&"
168e428f 2771This sets the prefix of the local part of the recipient address when a filter
9b371988 2772file is being tested by means of the &%-bf%& option. The default is an empty
168e428f
PH
2773prefix.
2774
9b371988
PH
2775.vitem &%-bfs%&&~<&'suffix'&>
2776.oindex "&%-bfs%&"
168e428f 2777This sets the suffix of the local part of the recipient address when a filter
9b371988 2778file is being tested by means of the &%-bf%& option. The default is an empty
168e428f
PH
2779suffix.
2780
9b371988
PH
2781.vitem &%-bh%&&~<&'IP&~address'&>
2782.oindex "&%-bh%&"
2783.cindex "testing" "incoming SMTP"
2784.cindex "SMTP" "testing incoming"
2785.cindex "testing" "relay control"
2786.cindex "relaying" "testing configuration"
2787.cindex "policy control" "testing"
2788.cindex "debugging" "&%-bh%& option"
168e428f
PH
2789This option runs a fake SMTP session as if from the given IP address, using the
2790standard input and output. The IP address may include a port number at the end,
2791after a full stop. For example:
9b371988
PH
2792.code
2793exim -bh 10.9.8.7.1234
2794exim -bh fe80::a00:20ff:fe86:a061.5678
2795.endd
168e428f 2796When an IPv6 address is given, it is converted into canonical form. In the case
9b371988
PH
2797of the second example above, the value of &$sender_host_address$& after
2798conversion to the canonical form is
2799&`fe80:0000:0000:0a00:20ff:fe86:a061.5678`&.
2800
168e428f 2801Comments as to what is going on are written to the standard error file. These
9b371988 2802include lines beginning with &"LOG"& for anything that would have been logged.
168e428f
PH
2803This facility is provided for testing configuration options for incoming
2804messages, to make sure they implement the required policy. For example, you can
9b371988
PH
2805test your relay controls using &%-bh%&.
2806
2807&*Warning 1*&:
2808.cindex "RFC 1413"
db9452a9
PH
2809You can test features of the configuration that rely on ident (RFC 1413)
2810information by using the &%-oMt%& option. However, Exim cannot actually perform
2811an ident callout when testing using &%-bh%& because there is no incoming SMTP
2812connection.
9b371988
PH
2813
2814&*Warning 2*&: Address verification callouts (see section &<<SECTcallver>>&)
2815are also skipped when testing using &%-bh%&. If you want these callouts to
2816occur, use &%-bhc%& instead.
2817
168e428f
PH
2818Messages supplied during the testing session are discarded, and nothing is
2819written to any of the real log files. There may be pauses when DNS (and other)
9b371988 2820lookups are taking place, and of course these may time out. The &%-oMi%& option
db9452a9
PH
2821can be used to specify a specific IP interface and port if this is important,
2822and &%-oMaa%& and &%-oMai%& can be used to set parameters as if the SMTP
2823session were authenticated.
9b371988
PH
2824
2825The &'exim_checkaccess'& utility is a &"packaged"& version of &%-bh%& whose
168e428f 2826output just states whether a given recipient address from a given host is
9b371988 2827acceptable or not. See section &<<SECTcheckaccess>>&.
168e428f 2828
3cb1b51e 2829Features such as authentication and encryption, where the client input is not
f89d2485
PH
2830plain text, cannot easily be tested with &%-bh%&. Instead, you should use a
2831specialized SMTP test program such as
3cb1b51e 2832&url(http://jetmore.org/john/code/#swaks,swaks).
3cb1b51e 2833
9b371988
PH
2834.vitem &%-bhc%&&~<&'IP&~address'&>
2835.oindex "&%-bhc%&"
2836This option operates in the same way as &%-bh%&, except that address
168e428f
PH
2837verification callouts are performed if required. This includes consulting and
2838updating the callout cache database.
2839
9b371988
PH
2840.vitem &%-bi%&
2841.oindex "&%-bi%&"
2842.cindex "alias file" "building"
2843.cindex "building alias file"
2844.cindex "Sendmail compatibility" "&%-bi%& option"
2845Sendmail interprets the &%-bi%& option as a request to rebuild its alias file.
168e428f 2846Exim does not have the concept of a single alias file, and so it cannot mimic
9b371988 2847this behaviour. However, calls to &_/usr/lib/sendmail_& with the &%-bi%& option
168e428f
PH
2848tend to appear in various scripts such as NIS make files, so the option must be
2849recognized.
9b371988
PH
2850
2851If &%-bi%& is encountered, the command specified by the &%bi_command%&
168e428f 2852configuration option is run, under the uid and gid of the caller of Exim. If
9b371988
PH
2853the &%-oA%& option is used, its value is passed to the command as an argument.
2854The command set by &%bi_command%& may not contain arguments. The command can
2855use the &'exim_dbmbuild'& utility, or some other means, to rebuild alias files
2856if this is required. If the &%bi_command%& option is not set, calling Exim with
2857&%-bi%& is a no-op.
2858
2859.vitem &%-bm%&
2860.oindex "&%-bm%&"
2861.cindex "local message reception"
168e428f
PH
2862This option runs an Exim receiving process that accepts an incoming,
2863locally-generated message on the current input. The recipients are given as the
9b371988 2864command arguments (except when &%-t%& is also present &-- see below). Each
168e428f
PH
2865argument can be a comma-separated list of RFC 2822 addresses. This is the
2866default option for selecting the overall action of an Exim call; it is assumed
2867if no other conflicting option is present.
9b371988 2868
168e428f 2869If any addresses in the message are unqualified (have no domain), they are
9b371988
PH
2870qualified by the values of the &%qualify_domain%& or &%qualify_recipient%&
2871options, as appropriate. The &%-bnq%& option (see below) provides a way of
168e428f 2872suppressing this for special cases.
9b371988 2873
168e428f 2874Policy checks on the contents of local messages can be enforced by means of
9b371988
PH
2875the non-SMTP ACL. See chapter &<<CHAPACL>>& for details.
2876
2877.cindex "return code" "for &%-bm%&"
2878The return code is zero if the message is successfully accepted. Otherwise, the
2879action is controlled by the &%-oe%&&'x'& option setting &-- see below.
2880
168e428f 2881The format
9b371988
PH
2882.cindex "message" "format"
2883.cindex "format" "message"
2884.cindex "&""From""& line"
2885.cindex "UUCP" "&""From""& line"
2886.cindex "Sendmail compatibility" "&""From""& line"
168e428f
PH
2887of the message must be as defined in RFC 2822, except that, for
2888compatibility with Sendmail and Smail, a line in one of the forms
9b371988
PH
2889.code
2890From sender Fri Jan 5 12:55 GMT 1997
2891From sender Fri, 5 Jan 97 12:55:01
2892.endd
168e428f
PH
2893(with the weekday optional, and possibly with additional text after the date)
2894is permitted to appear at the start of the message. There appears to be no
2895authoritative specification of the format of this line. Exim recognizes it by
9b371988 2896matching against the regular expression defined by the &%uucp_from_pattern%&
168e428f 2897option, which can be changed if necessary.
9b371988 2898
f89d2485
PH
2899.oindex "&%-f%&" "overriding &""From""& line"
2900The specified sender is treated as if it were given as the argument to the
9b371988 2901&%-f%& option, but if a &%-f%& option is also present, its argument is used in
168e428f
PH
2902preference to the address taken from the message. The caller of Exim must be a
2903trusted user for the sender of a message to be set in this way.
2904
9b371988
PH
2905.vitem &%-bnq%&
2906.oindex "&%-bnq%&"
f89d2485 2907.cindex "address qualification, suppressing"
168e428f
PH
2908By default, Exim automatically qualifies unqualified addresses (those
2909without domains) that appear in messages that are submitted locally (that
2910is, not over TCP/IP). This qualification applies both to addresses in
2911envelopes, and addresses in header lines. Sender addresses are qualified using
9b371988
PH
2912&%qualify_domain%&, and recipient addresses using &%qualify_recipient%& (which
2913defaults to the value of &%qualify_domain%&).
2914
2915Sometimes, qualification is not wanted. For example, if &%-bS%& (batch SMTP) is
168e428f
PH
2916being used to re-submit messages that originally came from remote hosts after
2917content scanning, you probably do not want to qualify unqualified addresses in
2918header lines. (Such lines will be present only if you have not enabled a header
2919syntax check in the appropriate ACL.)
9b371988
PH
2920
2921The &%-bnq%& option suppresses all qualification of unqualified addresses in
168e428f
PH
2922messages that originate on the local host. When this is used, unqualified
2923addresses in the envelope provoke errors (causing message rejection) and
2924unqualified addresses in header lines are left alone.
2925
2926
9b371988
PH
2927.vitem &%-bP%&
2928.oindex "&%-bP%&"
595028e4 2929.cindex "configuration options" "extracting"
9b371988 2930.cindex "options" "configuration &-- extracting"
168e428f
PH
2931If this option is given with no arguments, it causes the values of all Exim's
2932main configuration options to be written to the standard output. The values
2933of one or more specific options can be requested by giving their names as
2934arguments, for example:
9b371988
PH
2935.code
2936exim -bP qualify_domain hold_domains
2937.endd
595028e4
PH
2938.cindex "hiding configuration option values"
2939.cindex "configuration options" "hiding value of"
2940.cindex "options" "hiding value of"
9b371988 2941However, any option setting that is preceded by the word &"hide"& in the
168e428f
PH
2942configuration file is not shown in full, except to an admin user. For other
2943users, the output is as in this example:
9b371988
PH
2944.code
2945mysql_servers = <value not displayable>
2946.endd
2947If &%configure_file%& is given as an argument, the name of the run time
168e428f
PH
2948configuration file is output.
2949If a list of configuration files was supplied, the value that is output here
2950is the name of the file that was actually used.
168e428f 2951
9b371988
PH
2952.cindex "daemon" "process id (pid)"
2953.cindex "pid (process id)" "of daemon"
2954If &%log_file_path%& or &%pid_file_path%& are given, the names of the
2955directories where log files and daemon pid files are written are output,
2956respectively. If these values are unset, log files are written in a
2957sub-directory of the spool directory called &%log%&, and the pid file is
2958written directly into the spool directory.
2959
2960If &%-bP%& is followed by a name preceded by &`+`&, for example,
2961.code
2962exim -bP +local_domains
2963.endd
168e428f
PH
2964it searches for a matching named list of any type (domain, host, address, or
2965local part) and outputs what it finds.
9b371988
PH
2966
2967.cindex "options" "router &-- extracting"
2968.cindex "options" "transport &-- extracting"
2969If one of the words &%router%&, &%transport%&, or &%authenticator%& is given,
168e428f
PH
2970followed by the name of an appropriate driver instance, the option settings for
2971that driver are output. For example:
9b371988
PH
2972.code
2973exim -bP transport local_delivery
2974.endd
168e428f
PH
2975The generic driver options are output first, followed by the driver's private
2976options. A list of the names of drivers of a particular type can be obtained by
9b371988
PH
2977using one of the words &%router_list%&, &%transport_list%&, or
2978&%authenticator_list%&, and a complete list of all drivers with their option
2979settings can be obtained by using &%routers%&, &%transports%&, or
2980&%authenticators%&.
168e428f
PH
2981
2982
9b371988
PH
2983.vitem &%-bp%&
2984.oindex "&%-bp%&"
2985.cindex "queue" "listing messages on"
2986.cindex "listing" "messages on the queue"
168e428f 2987This option requests a listing of the contents of the mail queue on the
9b371988 2988standard output. If the &%-bp%& option is followed by a list of message ids,
168e428f 2989just those messages are listed. By default, this option can be used only by an
9b371988 2990admin user. However, the &%queue_list_requires_admin%& option can be set false
168e428f 2991to allow any user to see the queue.
168e428f 2992
9b371988
PH
2993Each message on the queue is displayed as in the following example:
2994.code
299525m 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"
3001The first line contains the length of time the message has been on the queue
168e428f
PH
3002(in this case 25 minutes), the size of the message (2.9K), the unique local
3003identifier for the message, and the message sender, as contained in the
3004envelope. For bounce messages, the sender address is empty, and appears as
9b371988 3005&"<>"&. If the message was submitted locally by an untrusted user who overrode
168e428f
PH
3006the default sender address, the user's login name is shown in parentheses
3007before the sender address.
9b371988
PH
3008
3009.cindex "frozen messages" "in queue listing"
3010If the message is frozen (attempts to deliver it are suspended) then the text
3011&"*** frozen ***"& is displayed at the end of this line.
3012
168e428f
PH
3013The recipients of the message (taken from the envelope, not the headers) are
3014displayed on subsequent lines. Those addresses to which the message has already
3015been delivered are marked with the letter D. If an original address gets
3016expanded into several addresses via an alias or forward file, the original is
3017displayed with a D only when deliveries for all of its child addresses are
3018complete.
3019
3020
9b371988
PH
3021.vitem &%-bpa%&
3022.oindex "&%-bpa%&"
3023This option operates like &%-bp%&, but in addition it shows delivered addresses
168e428f 3024that were generated from the original top level address(es) in each message by
9b371988
PH
3025alias or forwarding operations. These addresses are flagged with &"+D"& instead
3026of just &"D"&.
168e428f
PH
3027
3028
9b371988
PH
3029.vitem &%-bpc%&
3030.oindex "&%-bpc%&"
3031.cindex "queue" "count of messages on"
168e428f
PH
3032This option counts the number of messages on the queue, and writes the total
3033to the standard output. It is restricted to admin users, unless
9b371988 3034&%queue_list_requires_admin%& is set false.
168e428f
PH
3035
3036
9b371988
PH
3037.vitem &%-bpr%&
3038.oindex "&%-bpr%&"
3039This option operates like &%-bp%&, but the output is not sorted into
168e428f
PH
3040chronological order of message arrival. This can speed it up when there are
3041lots of messages on the queue, and is particularly useful if the output is
3042going to be post-processed in a way that doesn't need the sorting.
3043
9b371988
PH
3044.vitem &%-bpra%&
3045.oindex "&%-bpra%&"
3046This option is a combination of &%-bpr%& and &%-bpa%&.
168e428f 3047
9b371988
PH
3048.vitem &%-bpru%&
3049.oindex "&%-bpru%&"
3050This option is a combination of &%-bpr%& and &%-bpu%&.
168e428f
PH
3051
3052
9b371988
PH
3053.vitem &%-bpu%&
3054.oindex "&%-bpu%&"
3055This option operates like &%-bp%& but shows only undelivered top-level
3056addresses for each message displayed. Addresses generated by aliasing or
3057forwarding are not shown, unless the message was deferred after processing by a
3058router with the &%one_time%& option set.
168e428f
PH
3059
3060
9b371988
PH
3061.vitem &%-brt%&
3062.oindex "&%-brt%&"
3063.cindex "testing" "retry configuration"
3064.cindex "retry" "configuration te