Testsuite: account for platforms not supporting TFO, redux
[exim.git] / src / README.UPDATING
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1This document contains detailed information about incompatibilities that might
2be encountered when upgrading from one release of Exim to another. The
3information is in reverse order of release numbers. Mostly these are relatively
4small points, and the configuration file is normally upwards compatible, but
5there have been two big upheavals...
6
7
8**************************************************************************
9* There was a big reworking of the way mail routing works for release *
10* 4.00. Previously used "directors" were abolished, and all routing is *
11* now done by routers. Policy controls for incoming mail are now done by *
12* Access Control Lists instead of separate options. All this means that *
13* pre-4.00 configuration files have to be massively converted. If you *
14* are coming from a 3.xx release, please read the document in the file *
15* doc/Exim4.upgrade, and allow some time to complete the upgrade. *
16* *
17* There was a big reworking of the way domain/host/net/address lists are *
18* handled at release 3.00. If you are coming from a pre-3.00 release, it *
19* might be easier to start again from a default configuration. Otherwise *
20* you need to read doc/Exim3.upgrade and do a double conversion of your *
21* configuration file. *
22**************************************************************************
23
24
25The rest of this document contains information about changes in 4.xx releases
26that might affect a running system.
2eda48c6 27
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29Exim version 4.83
30-----------------
31
32 * SPF condition results renamed "permerror" and "temperror". The old
33 names are still accepted for back-compatability, for this release.
34
35 * TLS details are now logged on rejects, subject to log selectors.
36
37 * Items in headers_remove lists must now have any embedded list-separators
38 doubled.
39
40 * Attempted use of the deprecated options "gnutls_require_kx" et. al.
41 now result in logged warning.
42
43
2c422e6f 44Exim version 4.82
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45-----------------
46
2519e60d 47 * New option gnutls_allow_auto_pkcs11 defaults false; if you have GnuTLS 2.12.0
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48 or later and do want PKCS11 modules to be autoloaded, then set this option.
49
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50 * A per-transport wait-<name> database is no longer updated if the transport
51 sets "connection_max_messages" to 1, as it can not be used and causes
52 unnecessary serialisation and load. External tools tracking the state of
53 Exim by the hints databases may need modification to take this into account.
54
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55 * The av_scanner option can now accept multiple clamd TCP targets, all other
56 setting limitations remain.
57
a5f239e4 58
83e2f8a2 59Exim version 4.80
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60-----------------
61
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62 * BEWARE backwards-incompatible changes in SSL libraries, thus the version
63 bump. See points below for details.
c2b063d4 64 Also an LDAP data returned format change.
83e2f8a2 65
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66 * The value of $tls_peerdn is now print-escaped when written to the spool file
67 in a -tls_peerdn line, and unescaped when read back in. We received reports
68 of values with embedded newlines, which caused spool file corruption.
69
70 If you have a corrupt spool file and you wish to recover the contents after
71 upgrading, then lock the message, replace the new-lines that should be part
72 of the -tls_peerdn line with the two-character sequence \n and then unlock
73 the message. No tool has been provided as we believe this is a rare
74 occurence.
75
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76 * For OpenSSL, SSLv2 is now disabled by default. (GnuTLS does not support
77 SSLv2). RFC 6176 prohibits SSLv2 and some informal surveys suggest no
78 actual usage. You can re-enable with the "openssl_options" Exim option,
79 in the main configuration section. Note that supporting SSLv2 exposes
80 you to ciphersuite downgrade attacks.
81
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82 * With OpenSSL 1.0.1+, Exim now supports TLS 1.1 and TLS 1.2. If built
83 against 1.0.1a then you will get a warning message and the
84 "openssl_options" value will not parse "no_tlsv1_1": the value changes
85 incompatibly between 1.0.1a and 1.0.1b, because the value chosen for 1.0.1a
86 is infelicitous. We advise avoiding 1.0.1a.
87
88 "openssl_options" gains "no_tlsv1_1", "no_tlsv1_2" and "no_compression".
89
da3ad30d 90 COMPATIBILITY WARNING: The default value of "openssl_options" is no longer
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91 "+dont_insert_empty_fragments". We default to "+no_sslv2".
92 That old default was grandfathered in from before openssl_options became a
93 configuration option.
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94 Empty fragments are inserted by default through TLS1.0, to partially defend
95 against certain attacks; TLS1.1+ change the protocol so that this is not
96 needed. The DIEF SSL option was required for some old releases of mail
97 clients which did not gracefully handle the empty fragments, and was
98 initially set in Exim release 4.31 (see ChangeLog, item 37).
99
100 If you still have affected mail-clients, and you see SSL protocol failures
101 with this release of Exim, set:
102 openssl_options = +dont_insert_empty_fragments
103 in the main section of your Exim configuration file. You're trading off
104 security for compatibility. Exim is now defaulting to higher security and
105 rewarding more modern clients.
106
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107 If the option tls_dhparams is set and the parameters loaded from the file
108 have a bit-count greater than the new option tls_dh_max_bits, then the file
109 will now be ignored. If this affects you, raise the tls_dh_max_bits limit.
110 We suspect that most folks are using dated defaults and will not be affected.
111
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112 * Ldap lookups returning multi-valued attributes now separate the attributes
113 with only a comma, not a comma-space sequence. Also, an actual comma within
114 a returned attribute is doubled. This makes it possible to parse the
115 attribute as a comma-separated list. Note the distinction from multiple
116 attributes being returned, where each one is a name=value pair.
c80c5570 117
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118 If you are currently splitting the results from LDAP upon a comma, then you
119 should check carefully to see if adjustments are needed.
120
121 This change lets cautious folks distinguish "comma used as separator for
122 joining values" from "comma inside the data".
123
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124 * accept_8bitmime now defaults on, which is not RFC compliant but is better
125 suited to today's Internet. See http://cr.yp.to/smtp/8bitmime.html for a
126 sane rationale. Those who wish to be strictly RFC compliant, or know that
127 they need to talk to servers that are not 8-bit-clean, now need to take
128 explicit configuration action to default this option off. This is not a
129 new option, you can safely force it off before upgrading, to decouple
130 configuration changes from the binary upgrade while remaining RFC compliant.
131
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132 * The GnuTLS support has been mostly rewritten, to use APIs which don't cause
133 deprecation warnings in GnuTLS 2.12.x. As part of this, these three options
134 are no longer supported:
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135
136 gnutls_require_kx
137 gnutls_require_mac
138 gnutls_require_protocols
139
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140 Their functionality is entirely subsumed into tls_require_ciphers. In turn,
141 tls_require_ciphers is no longer an Exim list and is not parsed by Exim, but
142 is instead given to gnutls_priority_init(3), which expects a priority string;
143 this behaviour is much closer to the OpenSSL behaviour. See:
17c76198 144
42bfef1e 145 http://www.gnutls.org/manual/html_node/Priority-Strings.html
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146
147 for fuller documentation of the strings parsed. The three gnutls_require_*
148 options are still parsed by Exim and, for this release, silently ignored.
149 A future release will add warnings, before a later still release removes
150 parsing entirely and the presence of the options will be a configuration
151 error.
152
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153 Note that by default, GnuTLS will not accept RSA-MD5 signatures in chains.
154 A tls_require_ciphers value of NORMAL:%VERIFY_ALLOW_SIGN_RSA_MD5 may
155 re-enable support, but this is not supported by the Exim maintainers.
156 Our test suite no longer includes MD5-based certificates.
157
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158 This rewrite means that Exim will continue to build against GnuTLS in the
159 future, brings Exim closer to other GnuTLS applications and lets us add
160 support for SNI and other features more readily. We regret that it wasn't
161 feasible to retain the three dropped options.
162
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163 * If built with TLS support, then Exim will now validate the value of
164 the main section tls_require_ciphers option at start-up. Before, this
165 would cause a STARTTLS 4xx failure, now it causes a failure to start.
166 Running with a broken configuration which causes failures that may only
167 be left in the logs has been traded off for something more visible. This
168 change makes an existing problem more prominent, but we do not believe
169 anyone would deliberately be running with an invalid tls_require_ciphers
170 option.
171
172 This also means that library linkage issues caused by conflicts of some
173 kind might take out the main daemon, not just the delivery or receiving
174 process. Conceivably some folks might prefer to continue delivering
175 mail plaintext when their binary is broken in this way, if there is a
176 server that is a candidate to receive such mails that does not advertise
177 STARTTLS. Note that Exim is typically a setuid root binary and given
178 broken linkage problems that cause segfaults, we feel it is safer to
179 fail completely. (The check is not done as root, to ensure that problems
180 here are not made worse by the check).
181
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182 * The "tls_dhparam" option has been updated, so that it can now specify a
183 path or an identifier for a standard DH prime from one of a few RFCs.
184 The default for OpenSSL is no longer to not use DH but instead to use
185 one of these standard primes. The default for GnuTLS is no longer to use
186 a file in the spool directory, but to use that same standard prime.
187 The option is now used by GnuTLS too. If it points to a path, then
188 GnuTLS will use that path, instead of a file in the spool directory;
189 GnuTLS will attempt to create it if it does not exist.
190
191 To preserve the previous behaviour of generating files in the spool
192 directory, set "tls_dhparam = historic". Since prior releases of Exim
193 ignored tls_dhparam when using GnuTLS, this can safely be done before
194 the upgrade.
195
196
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198Exim version 4.77
199-----------------
200
201 * GnuTLS will now attempt to use TLS 1.2 and TLS 1.1 before TLS 1.0 and SSL3,
202 if supported by your GnuTLS library. Use the existing
203 "gnutls_require_protocols" option to downgrade this if that will be a
204 problem. Prior to this release, supported values were "TLS1" and "SSL3",
205 so you should be able to update configuration prior to update.
206
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207 [nb: gnutls_require_protocols removed in Exim 4.80, instead use
208 tls_require_ciphers to provide a priority string; see notes above]
209
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210 * The match_<type>{string1}{string2} expansion conditions no longer subject
211 string2 to string expansion, unless Exim was built with the new
212 "EXPAND_LISTMATCH_RHS" option. Too many people have inadvertently created
213 insecure configurations that way. If you need the functionality and turn on
214 that build option, please let the developers know, and know why, so we can
215 try to provide a safer mechanism for you.
216
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217 The match{}{} expansion condition (for regular expressions) is NOT affected.
218 For match_<type>{s1}{s2}, all list functionality is unchanged. The only
219 change is that a '$' appearing in s2 will not trigger expansion, but instead
220 will be treated as a literal $ sign; the effect is very similar to having
221 wrapped s2 with \N...\N. If s2 contains a named list and the list definition
222 uses $expansions then those _will_ be processed as normal. It is only the
223 point at which s2 is read where expansion is inhibited.
224
225 If you are trying to test if two email addresses are equal, use eqi{s1}{s2}.
226 If you are testing if the address in s1 occurs in the list of items given
227 in s2, either use the new inlisti{s1}{s2} condition (added in 4.77) or use
228 the pre-existing forany{s2}{eqi{$item}{s1}} condition.
229
c566dd90 230
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231Exim version 4.74
232-----------------
233
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234 * The integrated support for dynamically loadable lookup modules has an ABI
235 change from the modules supported by some OS vendors through an unofficial
236 patch. Don't try to mix & match.
237
238 * Some parts of the build system are now beginning to assume that the host
239 environment is POSIX. If you're building on a system where POSIX tools are
240 not the default, you might have an easier time if you switch to the POSIX
241 tools. Feel free to report non-POSIX issues as a request for a feature
242 enhancement, but if the POSIX variants are available then the fix will
243 probably just involve some coercion. See the README instructions for
244 building on such hosts.
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245
246
247Exim version 4.73
248-----------------
249
250 * The Exim run-time user can no longer be root; this was always
251 strongly discouraged, but is now prohibited both at build and
252 run-time. If you need Exim to run routinely as root, you'll need to
253 patch the source and accept the risk. Here be dragons.
254
255 * Exim will no longer accept a configuration file owned by the Exim
256 run-time user, unless that account is explicitly the value in
257 CONFIGURE_OWNER, which we discourage. Exim now checks to ensure that
a7ee5955 258 files are not writeable by other accounts.
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259
260 * The ALT_CONFIG_ROOT_ONLY build option is no longer optional and is forced
261 on; the Exim user can, by default, no longer use -C/-D and retain privilege.
262 Two new build options mitigate this.
263
264 * TRUSTED_CONFIG_LIST defines a file containing a whitelist of config
265 files that are trusted to be selected by the Exim user; one per line.
266 This is the recommended approach going forward.
267
268 * WHITELIST_D_MACROS defines a colon-separated list of macro names which
269 the Exim run-time user may safely pass without dropping privileges.
270 Because changes to this involve a recompile, this is not the recommended
271 approach but may ease transition. The values of the macros, when
43236f35 272 overridden, are constrained to match this regex: ^[A-Za-z0-9_/.-]*$
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273
274 * The system_filter_user option now defaults to the Exim run-time user,
275 rather than root. You can still set it explicitly to root and this
276 can be done with prior versions too, letting you roll versions
277 without needing to change this configuration option.
278
279 * ClamAV must be at least version 0.95 unless WITH_OLD_CLAMAV_STREAM is
280 defined at build time.
281
282
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283Exim version 4.70
284-----------------
285
2861. Experimental Yahoo! Domainkeys support has been dropped in this release.
287It has been superceded by a native implementation of its successor DKIM.
288
2892. Up to version 4.69, Exim came with an embedded version of the PCRE library.
290As of 4.70, this is no longer the case. To compile Exim, you will need PCRE
a7ee5955 291installed. Most OS distributions have ready-made library and development
2eda48c6 292packages.
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293
294
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295Exim version 4.68
296-----------------
297
2981. The internal implementation of the database keys that are used for ACL
299ratelimiting has been tidied up. This means that an update to 4.68 might cause
300Exim to "forget" previous rates that it had calculated, and reset them to zero.
301
302
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303Exim version 4.64
304-----------------
305
3061. Callouts were setting the name used for EHLO/HELO from $smtp_active_
307hostname. This is wrong, because it relates to the incoming message (and
308probably the interface on which it is arriving) and not to the outgoing
309callout (which could be using a different interface). This has been
310changed to use the value of the helo_data option from the smtp transport
311instead - this is what is used when a message is actually being sent. If
312there is no remote transport (possible with a router that sets up host
313addresses), $smtp_active_hostname is used. This change is mentioned here in
314case somebody is relying on the use of $smtp_active_hostname.
315
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3162. A bug has been fixed that might just possibly be something that is relied on
317in some configurations. In expansion items such as ${if >{xxx}{yyy}...} an
318empty string (that is {}) was being interpreted as if it was {0} and therefore
319treated as the number zero. From release 4.64, such strings cause an error
320because a decimal number, possibly followed by K or M, is required (as has
321always been documented).
322
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3233. There has been a change to the GnuTLS support (ChangeLog/PH/20) to improve
324Exim's performance. Unfortunately, this has the side effect of being slightly
325non-upwards compatible for versions 4.50 and earlier. If you are upgrading from
326one of these earlier versions and you use GnuTLS, you must remove the file
327called gnutls-params in Exim's spool directory. If you don't do this, you will
328see this error:
329
330 TLS error on connection from ... (DH params import): Base64 decoding error.
331
332Removing the file causes Exim to recompute the relevant encryption parameters
333and cache them in the new format that was introduced for release 4.51 (May
3342005). If you are upgrading from release 4.51 or later, there should be no
335problem.
336
26da7e20 337
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338Exim version 4.63
339-----------------
340
341When an SMTP error message is specified in a "message" modifier in an ACL, or
342in a :fail: or :defer: message in a redirect router, Exim now checks the start
343of the message for an SMTP error code. This consists of three digits followed
344by a space, optionally followed by an extended code of the form n.n.n, also
345followed by a space. If this is the case and the very first digit is the same
346as the default error code, the code from the message is used instead. If the
347very first digit is incorrect, a panic error is logged, and the default code is
348used. This is an incompatible change, but it is not expected to affect many (if
349any) configurations. It is possible to suppress the use of the supplied code in
350a redirect router by setting the smtp_error_code option false. In this case,
351any SMTP code is quietly ignored.
352
353
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354Exim version 4.61
355-----------------
356
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3571. The default number of ACL variables of each type has been increased to 20,
358and it's possible to compile Exim with more. You can safely upgrade to this
359release if you already have messages on the queue with saved ACL variable
360values. However, if you downgrade from this release with messages on the queue,
361any saved ACL values they may have will be lost.
362
3632. The default value for rfc1413_query_timeout has been changed from 30s to 5s.
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364
365
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366Exim version 4.54
367-----------------
368
369There was a problem with 4.52/TF/02 in that a "name=" option on control=
370submission terminated at the next slash, thereby not allowing for slashes in
371the name. This has been changed so that "name=" takes the rest of the string as
372its data. It must therefore be the last option.
373
374
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375Version 4.53
376------------
377
378If you are using the experimental Domain Keys support, you must upgrade to
379at least libdomainkeys 0.67 in order to run this release of Exim.
380
381
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382Version 4.51
383------------
384
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3851. The format in which GnuTLS parameters are cached (in the file gnutls-params
386in the spool directory) has been changed. The new format can also be generated
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387externally, so it is now possible to update the values from outside Exim. This
388has been implemented in an upwards, BUT NOT downwards, compatible manner.
389Upgrading should be seamless: when Exim finds that it cannot understand an
390existing cache file, it generates new parameters and writes them to the cache
391in the new format. If, however, you downgrade from 4.51 to a previous release,
392you MUST delete the gnutls-params file in the spool directory, because the
393older Exim will not recognize the new format.
394
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3952. When doing a callout as part of verifying an address, Exim was not paying
396attention to any local part prefix or suffix that was matched by the router
397that accepted the address. It now behaves in the same way as it does for
398delivery: the affixes are removed from the local part unless
399rcpt_include_affixes is set on the transport. If you have a configuration that
400uses prefixes or suffixes on addresses that could be used for callouts, and you
401want the affixes to be retained, you must make sure that rcpt_include_affixes
402is set on the transport.
403
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4043. Bounce and delay warning messages no longer contain details of delivery
405errors, except for explicit messages (e.g. generated by :fail:) and SMTP
406responses from remote hosts.
407
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409Version 4.50
410------------
411
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412The exicyclog script has been updated to use three-digit numbers in rotated log
413files if the maximum number to keep is greater than 99. If you are already
414keeping more than 99, there will be an incompatible change when you upgrade.
415You will probably want to rename your old log files to the new form before
c3af992c 416running the new exicyclog.
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417
418
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419Version 4.42
420------------
421
422RFC 3848 specifies standard names for the "with" phrase in Received: header
423lines when AUTH and/or TLS are in use. This is the "received protocol"
424field. Exim used to use "asmtp" for authenticated SMTP, without any
425indication (in the protocol name) for TLS use. Now it follows the RFC and
426uses "esmtpa" if the connection is authenticated, "esmtps" if it is
427encrypted, and "esmtpsa" if it is both encrypted and authenticated. These names
428appear in log lines as well as in Received: header lines.
429
430
431Version 4.34
432------------
433
434Change 4.31/2 gave problems to data ACLs and local_scan() functions that
435expected to see a Received: header. I have changed to yet another scheme. The
436Received: header is now generated after the body is received, but before the
437ACL or local_scan() is called. After they have run, the timestamp in the
438Received: header is updated.
439
440Thus, change (a) of 4.31/2 has been reversed, but change (b) is still true,
441which is lucky, since I decided it was a bug fix.
442
443
444Version 4.33
445------------
446
447If an expansion in a condition on a "warn" statement fails because a lookup
448defers, the "warn" statement is abandoned, and the next ACL statement is
449processed. Previously this caused the whole ACL to be aborted.
450
451
452Version 4.32
453------------
454
455Change 4.31/2 has been reversed, as it proved contentious. Recipient callout
456verification now uses <> in the MAIL command by default, as it did before. A
457new callout option, "use_sender", has been added to request the other
458behaviour.
459
460
461Version 4.31
462------------
463
4641. If you compile Exim to use GnuTLS, it now requires the use of release 1.0.0
465 or greater. The interface to the obsolete 0.8.x releases is no longer
466 supported. There is one externally visible change: the format for the
467 display of Distinguished Names now uses commas as a separator rather than a
468 slash. This is to comply with RFC 2253.
469
4702. When a message is received, the Received: header line is now generated when
471 reception is complete, instead of at the start of reception. For messages
472 that take a long time to come in, this changes the meaning of the timestamp.
473 There are several side-effects of this change:
474
475 (a) If a message is rejected by a DATA or non-SMTP ACL, or by local_scan(),
476 the logged header lines no longer include the local Received: line,
477 because it has not yet been created. If the message is a non-SMTP one,
478 and the error is processed by sending a message to the sender, the copy
479 of the original message that is returned does not have an added
480 Received: line.
481
482 (b) When a filter file is tested using -bf, no additional Received: header
483 is added to the test message. After some thought, I decided that this
484 is a bug fix.
485
486 The contents of $received_for are not affected by this change. This
487 variable still contains the single recipient of a message, copied after
488 addresses have been rewritten, but before local_scan() is run.
489
4902. Recipient callout verification, like sender verification, was using <> in
491 the MAIL FROM command. This isn't really the right thing, since the actual
492 sender may affect whether the remote host accepts the recipient or not. I
493 have changed it to use the actual sender in the callout; this means that
494 the cache record is now keyed on a recipient/sender pair, not just the
495 recipient address. There doesn't seem to be a real danger of callout loops,
496 since a callout by the remote host to check the sender would use <>.
497
498
499Version 4.30
500------------
501
5021. I have abolished timeout_DNS as an error that can be detected in retry
503 rules, because it has never worked. Despite the fact that it has been
504 documented since at least release 1.62, there was no code to support it.
505 If you have used it in your retry rules, you will now get a warning message
506 to the log and panic log. It is now treated as plain "timeout".
507
5082. After discussion on the mailing list, Exim no longer adds From:, Date:, or
509 Message-Id: header lines to messages that do not originate locally, that is,
510 messages that have an associated sending host address.
511
5123. When looking up a host name from an IP address, Exim now tries the DNS
513 first, and only if that fails does it use gethostbyaddr() (or equivalent).
514 This change was made because on some OS, not all the names are given for
515 addresses with multiple PTR records via the gethostbyaddr() interface. The
516 order of lookup can be changed by setting host_lookup_order.
517
518
519Version 4.23
520------------
521
5221. The new FIXED_NEVER_USERS build-time option creates a list of "never users"
523 that cannot be overridden. The default in the distributed EDITME is "root".
524 If for some reason you were (against advice) running deliveries as root, you
525 will have to ensure that FIXED_NEVER_USERS is not set in your
526 Local/Makefile.
527
5282. The ${quote: operator now quotes an empty string, which it did not before.
529
5303. Version 4.23 saves the contents of the ACL variables with the message, so
531 that they can be used later. If one of these variables contains a newline,
532 there will be a newline character in the spool that will not be interpreted
533 correctely by a previous version of Exim. (Exim ignores keyed spool file
534 items that it doesn't understand - precisely for this kind of problem - but
535 it expects them all to be on one line.)
536
537 So the bottom line is: if you have newlines in your ACL variables, you
538 cannot retreat from 4.23.
539
540
541Version 4.21
542------------
543
5441. The idea of the "warn" ACL verb is that it adds a header or writes to the
545 log only when "message" or "log_message" are set. However, if one of the
546 conditions was an address verification, or a call to a nested ACL, the
547 messages generated by the underlying test were being passed through. This
548 no longer happens. The underlying message is available in $acl_verify_
549 message for both "message" and "log_message" expansions, so it can be
550 passed through if needed.
551
5522. The way that the $h_ (and $header_) expansions work has been changed by the
553 addition of RFC 2047 decoding. See the main documentation (the NewStuff file
554 until release 4.30, then the manual) for full details. Briefly, there are
555 now three forms:
556
557 $rh_xxx: and $rheader_xxx: give the original content of the header
558 line(s), with no processing at all.
559
560 $bh_xxx: and $bheader_xxx: remove leading and trailing white space, and
561 then decode base64 or quoted-printable "words" within the header text,
562 but do not do charset translation.
563
564 $h_xxx: and $header_xxx: attempt to translate the $bh_ string to a
565 standard character set.
566
567 If you have previously been using $h_ expansions to access the raw
568 characters, you should change to $rh_ instead.
569
5703. When Exim creates an RFC 2047 encoded word in a header line, it labels it
571 with the default character set from the headers_charset option instead of
572 always using iso-8859-1.
573
5744. If TMPDIR is defined in Local/Makefile (default in src/EDITME is
575 TMPDIR="/tmp"), Exim checks for the presence of an environment variable
576 called TMPDIR, and if it finds it is different, it changes its value.
577
5785. Following a discussion on the list, the rules by which Exim recognises line
579 endings on incoming messages have been changed. The -dropcr and drop_cr
580 options are now no-ops, retained only for backwards compatibility. The
581 following line terminators are recognized: LF CRLF CR. However, special
582 processing applies to CR:
583
584 (i) The sequence CR . CR does *not* terminate an incoming SMTP message,
585 nor a local message in the state where . is a terminator.
586
587 (ii) If a bare CR is encountered in a header line, an extra space is added
588 after the line terminator so as not to end the header. The reasoning
589 behind this is that bare CRs in header lines are most likely either
590 to be mistakes, or people trying to play silly games.
591
5926. The code for using daemon_smtp_port, local_interfaces, and the -oX options
593 has been reorganized. It is supposed to be backwards compatible, but it is
594 mentioned here just in case I've screwed up.
595
596
597
598Version 4.20
599------------
600
6011. I have tidied and re-organized the code that uses alarm() for imposing time
602 limits on various things. It shouldn't affect anything, but if you notice
603 processes getting stuck, it may be that I've broken something.
604
6052. The "arguments" log selector now also logs the current working directory
606 when Exim is called.
607
6083. An incompatible change has been made to the appendfile transport. This
609 affects the case when it is used for file deliveries that are set up by
610 .forward and filter files. Previously, any settings of the "file" or
611 "directory" options were ignored. It is hoped that, like the address_file
612 transport in the default configuration, these options were never in fact set
613 on such transports, because they were of no use.
614
615 Now, if either of these options is set, it is used. The path that is passed
616 by the router is in $address_file (this is not new), so it can be used as
617 part of a longer path, or modified in any other way that expansion permits.
618
619 If neither "file" nor "directory" is set, the behaviour is unchanged.
620
6214. Related to the above: in a filter, if a "save" command specifies a non-
622 absolute path, the value of $home/ is pre-pended. This no longer happens if
623 $home is unset or is set to an empty string.
624
6255. Multiple file deliveries from a filter or .forward file can never be
626 batched; the value of batch_max on the transport is ignored for file
627 deliveries. I'm assuming that nobody ever actually set batch_max on the
628 address_file transport - it would have had odd effects previously.
629
6306. DESTDIR is the more common variable that ROOT for use when installing
631 software under a different root filing system. The Exim install script now
632 recognizes DESTDIR first; if it is not set, ROOT is used.
633
6347. If DESTDIR is set when installing Exim, it no longer prepends its value to
635 the path of the system aliases file that appears in the default
636 configuration (when a default configuration is installed). If an aliases
637 file is actually created, its name *does* use the prefix.
638
639
640Version 4.14
641------------
642
6431. The default for the maximum number of unknown SMTP commands that Exim will
644accept before dropping a connection has been reduced from 5 to 3. However, you
645can now change the value by setting smtp_max_unknown_commands.
646
6472. The ${quote: operator has been changed so that it turns newline and carriage
648return characters into \n and \r, respectively.
649
6503. The file names used for maildir messages now include the microsecond time
651fraction as well as the time in seconds, to cope with systems where the process
652id can be re-used within the same second. The format is now
653
654 <time>.H<microsec>P<pid>.<host>
655
656This should be a compatible change, but is noted here just in case.
657
6584. The rules for creating message ids have changed, to cope with systems where
659the process id can be re-used within the same second. The format, however, is
660unchanged, so this should not cause any problems, except as noted in the next
661item.
662
6635. The maximum value for localhost_number has been reduced from 255 to 16, in
664order to implement the new message id rules. For operating systems that have
665case-insensitive file systems (Cygwin and Darwin), the limit is 10.
666
6676. verify = header_syntax was allowing unqualified addresses in all cases. Now
668it allows them only for locally generated messages and from hosts that match
669sender_unqualified_hosts or recipient_unqualified_hosts, respectively.
670
6717. For reasons lost in the mists of time, when a pipe transport was run, the
672environment variable MESSAGE_ID was set to the message ID preceded by 'E' (the
673form used in Message-ID: header lines). The 'E' has been removed.
674
675
676Version 4.11
677------------
678
6791. The handling of lines in the configuration file has changed. Previously,
680macro expansion was applied to logical lines, after continuations had been
681joined on. This meant that it could not be used in .include lines, which are
682handled as physical rather than logical lines. Macro expansion is now done on
683physical lines rather than logical lines. This means there are two
684incompatibilities:
685
686 (a) A macro that expands to # to turn a line into a comment now applies only
687 to the physical line where it appears. Previously, it would have caused
688 any following continuations also to be ignored.
689
690 (b) A macro name can no longer be split over the boundary between a line and
691 its continuation. Actually, this is more of a bug fix. :-)
692
6932. The -D command line option must now all be within one command line item.
694This makes it possible to use -D to set a macro to the empty string by commands
695such as
696
697 exim -DABC ...
698 exim -DABC= ...
699
700Previously, these items would have moved on to the next item on the command
701line. To include spaces in a macro definition item, quotes must be used, in
702which case you can also have spaces after -D and surrounding the equals. For
703example:
704
705 exim '-D ABC = something' ...
706
7073. The way that addresses that redirect to themselves are handled has been
708changed, in order to fix an obscure bug. This should not cause any problems
709except in the case of wanting to go back from a 4.11 (or later) release to an
710earlier release. If there are undelivered messages on the spool that contain
711addresses which redirect to themselves, and the redirected addresses have
712already been delivered, you might get a duplicate delivery if you revert to an
713earlier Exim.
714
7154. The default way of looking up IP addresses for hosts in the manualroute and
716queryprogram routers has been changed. If "byname" or "bydns" is explicitly
717specified, there is no change, but if no method is specified, Exim now behaves
718as follows:
719
720 First, a DNS lookup is done. If this yields anything other than
721 HOST_NOT_FOUND, that result is used. Otherwise, Exim goes on to try a call to
722 getipnodebyname() (or gethostbyname() on older systems) and the result of the
723 lookup is the result of that call.
724
725This change has been made because it has been discovered that on some systems,
726if a DNS lookup called via getipnodebyname() times out, HOST_NOT_FOUND is
727returned instead of TRY_AGAIN. Thus, it is safest to try a DNS lookup directly
728first, and only if that gives a definite "no such host" to try the local
729function.
730
7315. In fixing the minor security problem with pid_file_path, I have removed some
732backwards-compatible (undocumented) code which was present to ease conversion
733from Exim 3. In Exim 4, pid_file_path is a literal; in Exim 3 it was allowed to
734contain "%s", which was replaced by the port number for daemons listening on
735non-standard ports. In Exim 4, such daemons do not write a pid file. The
736backwards compatibility feature was to replace "%s" by nothing if it occurred
737in an Exim 4 setting of pid_file_path. The bug was in this code. I have solved
738the problem by removing the backwards compatibility feature. Thus, if you still
739have "%s" somewhere in a setting of pid_file_path, you should remove it.
740
7416. There has been an extension to lsearch files. The keys in these files may
742now be quoted in order to allow for whitespace and colons in them. This means
743that if you were previously using keys that began with a doublequote, you will
744now have to wrap them with extra quotes and escape the internal quotes. The
745possibility that anybody is actually doing this seems extremely remote, but it
746is documented just in case.
747
748
749Version 4.10
750------------
751
752The build-time parameter EXIWHAT_KILL_ARG has been renamed EXIWHAT_KILL_SIGNAL
753to better reflect its function. The OS-specific files have been updated. Only
754if you have explicitly set this in your Makefile (highly unlikely) do you need
755to change anything.
756
757****