Add log_reject_target as an ACL modifier.
[exim.git] / src / README.UPDATING
a5bd321b 1$Cambridge: exim/src/README.UPDATING,v 1.12 2006/07/13 13:53:33 ph10 Exp $
3This document contains detailed information about incompatibilities that might
4be encountered when upgrading from one release of Exim to another. The
5information is in reverse order of release numbers. Mostly these are relatively
6small points, and the configuration file is normally upwards compatible, but
7there have been two big upheavals...
11* There was a big reworking of the way mail routing works for release *
12* 4.00. Previously used "directors" were abolished, and all routing is *
13* now done by routers. Policy controls for incoming mail are now done by *
14* Access Control Lists instead of separate options. All this means that *
15* pre-4.00 configuration files have to be massively converted. If you *
16* are coming from a 3.xx release, please read the document in the file *
17* doc/Exim4.upgrade, and allow some time to complete the upgrade. *
18* *
19* There was a big reworking of the way domain/host/net/address lists are *
20* handled at release 3.00. If you are coming from a pre-3.00 release, it *
21* might be easier to start again from a default configuration. Otherwise *
22* you need to read doc/Exim3.upgrade and do a double conversion of your *
23* configuration file. *
27The rest of this document contains information about changes in 4.xx releases
28that might affect a running system.
31Exim version 4.63
34When an SMTP error message is specified in a "message" modifier in an ACL, or
35in a :fail: or :defer: message in a redirect router, Exim now checks the start
36of the message for an SMTP error code. This consists of three digits followed
37by a space, optionally followed by an extended code of the form n.n.n, also
38followed by a space. If this is the case and the very first digit is the same
39as the default error code, the code from the message is used instead. If the
40very first digit is incorrect, a panic error is logged, and the default code is
41used. This is an incompatible change, but it is not expected to affect many (if
42any) configurations. It is possible to suppress the use of the supplied code in
43a redirect router by setting the smtp_error_code option false. In this case,
44any SMTP code is quietly ignored.
47Exim version 4.61
501. The default number of ACL variables of each type has been increased to 20,
51and it's possible to compile Exim with more. You can safely upgrade to this
52release if you already have messages on the queue with saved ACL variable
53values. However, if you downgrade from this release with messages on the queue,
54any saved ACL values they may have will be lost.
562. The default value for rfc1413_query_timeout has been changed from 30s to 5s.
59Exim version 4.54
62There was a problem with 4.52/TF/02 in that a "name=" option on control=
63submission terminated at the next slash, thereby not allowing for slashes in
64the name. This has been changed so that "name=" takes the rest of the string as
65its data. It must therefore be the last option.
68Version 4.53
71If you are using the experimental Domain Keys support, you must upgrade to
72at least libdomainkeys 0.67 in order to run this release of Exim.
75Version 4.51
781. The format in which GnuTLS parameters are cached (in the file gnutls-params
79in the spool directory) has been changed. The new format can also be generated
80externally, so it is now possible to update the values from outside Exim. This
81has been implemented in an upwards, BUT NOT downwards, compatible manner.
82Upgrading should be seamless: when Exim finds that it cannot understand an
83existing cache file, it generates new parameters and writes them to the cache
84in the new format. If, however, you downgrade from 4.51 to a previous release,
85you MUST delete the gnutls-params file in the spool directory, because the
86older Exim will not recognize the new format.
882. When doing a callout as part of verifying an address, Exim was not paying
89attention to any local part prefix or suffix that was matched by the router
90that accepted the address. It now behaves in the same way as it does for
91delivery: the affixes are removed from the local part unless
92rcpt_include_affixes is set on the transport. If you have a configuration that
93uses prefixes or suffixes on addresses that could be used for callouts, and you
94want the affixes to be retained, you must make sure that rcpt_include_affixes
95is set on the transport.
973. Bounce and delay warning messages no longer contain details of delivery
98errors, except for explicit messages (e.g. generated by :fail:) and SMTP
99responses from remote hosts.
b5aea5e1 101
102Version 4.50
105The exicyclog script has been updated to use three-digit numbers in rotated log
106files if the maximum number to keep is greater than 99. If you are already
107keeping more than 99, there will be an incompatible change when you upgrade.
108You will probably want to rename your old log files to the new form before
c3af992c 109running the new exicyclog.
112Version 4.42
115RFC 3848 specifies standard names for the "with" phrase in Received: header
116lines when AUTH and/or TLS are in use. This is the "received protocol"
117field. Exim used to use "asmtp" for authenticated SMTP, without any
118indication (in the protocol name) for TLS use. Now it follows the RFC and
119uses "esmtpa" if the connection is authenticated, "esmtps" if it is
120encrypted, and "esmtpsa" if it is both encrypted and authenticated. These names
121appear in log lines as well as in Received: header lines.
124Version 4.34
127Change 4.31/2 gave problems to data ACLs and local_scan() functions that
128expected to see a Received: header. I have changed to yet another scheme. The
129Received: header is now generated after the body is received, but before the
130ACL or local_scan() is called. After they have run, the timestamp in the
131Received: header is updated.
133Thus, change (a) of 4.31/2 has been reversed, but change (b) is still true,
134which is lucky, since I decided it was a bug fix.
137Version 4.33
140If an expansion in a condition on a "warn" statement fails because a lookup
141defers, the "warn" statement is abandoned, and the next ACL statement is
142processed. Previously this caused the whole ACL to be aborted.
145Version 4.32
148Change 4.31/2 has been reversed, as it proved contentious. Recipient callout
149verification now uses <> in the MAIL command by default, as it did before. A
150new callout option, "use_sender", has been added to request the other
154Version 4.31
1571. If you compile Exim to use GnuTLS, it now requires the use of release 1.0.0
158 or greater. The interface to the obsolete 0.8.x releases is no longer
159 supported. There is one externally visible change: the format for the
160 display of Distinguished Names now uses commas as a separator rather than a
161 slash. This is to comply with RFC 2253.
1632. When a message is received, the Received: header line is now generated when
164 reception is complete, instead of at the start of reception. For messages
165 that take a long time to come in, this changes the meaning of the timestamp.
166 There are several side-effects of this change:
168 (a) If a message is rejected by a DATA or non-SMTP ACL, or by local_scan(),
169 the logged header lines no longer include the local Received: line,
170 because it has not yet been created. If the message is a non-SMTP one,
171 and the error is processed by sending a message to the sender, the copy
172 of the original message that is returned does not have an added
173 Received: line.
175 (b) When a filter file is tested using -bf, no additional Received: header
176 is added to the test message. After some thought, I decided that this
177 is a bug fix.
179 The contents of $received_for are not affected by this change. This
180 variable still contains the single recipient of a message, copied after
181 addresses have been rewritten, but before local_scan() is run.
1832. Recipient callout verification, like sender verification, was using <> in
184 the MAIL FROM command. This isn't really the right thing, since the actual
185 sender may affect whether the remote host accepts the recipient or not. I
186 have changed it to use the actual sender in the callout; this means that
187 the cache record is now keyed on a recipient/sender pair, not just the
188 recipient address. There doesn't seem to be a real danger of callout loops,
189 since a callout by the remote host to check the sender would use <>.
192Version 4.30
1951. I have abolished timeout_DNS as an error that can be detected in retry
196 rules, because it has never worked. Despite the fact that it has been
197 documented since at least release 1.62, there was no code to support it.
198 If you have used it in your retry rules, you will now get a warning message
199 to the log and panic log. It is now treated as plain "timeout".
2012. After discussion on the mailing list, Exim no longer adds From:, Date:, or
202 Message-Id: header lines to messages that do not originate locally, that is,
203 messages that have an associated sending host address.
2053. When looking up a host name from an IP address, Exim now tries the DNS
206 first, and only if that fails does it use gethostbyaddr() (or equivalent).
207 This change was made because on some OS, not all the names are given for
208 addresses with multiple PTR records via the gethostbyaddr() interface. The
209 order of lookup can be changed by setting host_lookup_order.
212Version 4.23
2151. The new FIXED_NEVER_USERS build-time option creates a list of "never users"
216 that cannot be overridden. The default in the distributed EDITME is "root".
217 If for some reason you were (against advice) running deliveries as root, you
218 will have to ensure that FIXED_NEVER_USERS is not set in your
219 Local/Makefile.
2212. The ${quote: operator now quotes an empty string, which it did not before.
2233. Version 4.23 saves the contents of the ACL variables with the message, so
224 that they can be used later. If one of these variables contains a newline,
225 there will be a newline character in the spool that will not be interpreted
226 correctely by a previous version of Exim. (Exim ignores keyed spool file
227 items that it doesn't understand - precisely for this kind of problem - but
228 it expects them all to be on one line.)
230 So the bottom line is: if you have newlines in your ACL variables, you
231 cannot retreat from 4.23.
234Version 4.21
2371. The idea of the "warn" ACL verb is that it adds a header or writes to the
238 log only when "message" or "log_message" are set. However, if one of the
239 conditions was an address verification, or a call to a nested ACL, the
240 messages generated by the underlying test were being passed through. This
241 no longer happens. The underlying message is available in $acl_verify_
242 message for both "message" and "log_message" expansions, so it can be
243 passed through if needed.
2452. The way that the $h_ (and $header_) expansions work has been changed by the
246 addition of RFC 2047 decoding. See the main documentation (the NewStuff file
247 until release 4.30, then the manual) for full details. Briefly, there are
248 now three forms:
250 $rh_xxx: and $rheader_xxx: give the original content of the header
251 line(s), with no processing at all.
253 $bh_xxx: and $bheader_xxx: remove leading and trailing white space, and
254 then decode base64 or quoted-printable "words" within the header text,
255 but do not do charset translation.
257 $h_xxx: and $header_xxx: attempt to translate the $bh_ string to a
258 standard character set.
260 If you have previously been using $h_ expansions to access the raw
261 characters, you should change to $rh_ instead.
2633. When Exim creates an RFC 2047 encoded word in a header line, it labels it
264 with the default character set from the headers_charset option instead of
265 always using iso-8859-1.
2674. If TMPDIR is defined in Local/Makefile (default in src/EDITME is
268 TMPDIR="/tmp"), Exim checks for the presence of an environment variable
269 called TMPDIR, and if it finds it is different, it changes its value.
2715. Following a discussion on the list, the rules by which Exim recognises line
272 endings on incoming messages have been changed. The -dropcr and drop_cr
273 options are now no-ops, retained only for backwards compatibility. The
274 following line terminators are recognized: LF CRLF CR. However, special
275 processing applies to CR:
277 (i) The sequence CR . CR does *not* terminate an incoming SMTP message,
278 nor a local message in the state where . is a terminator.
280 (ii) If a bare CR is encountered in a header line, an extra space is added
281 after the line terminator so as not to end the header. The reasoning
282 behind this is that bare CRs in header lines are most likely either
283 to be mistakes, or people trying to play silly games.
2856. The code for using daemon_smtp_port, local_interfaces, and the -oX options
286 has been reorganized. It is supposed to be backwards compatible, but it is
287 mentioned here just in case I've screwed up.
291Version 4.20
2941. I have tidied and re-organized the code that uses alarm() for imposing time
295 limits on various things. It shouldn't affect anything, but if you notice
296 processes getting stuck, it may be that I've broken something.
2982. The "arguments" log selector now also logs the current working directory
299 when Exim is called.
3013. An incompatible change has been made to the appendfile transport. This
302 affects the case when it is used for file deliveries that are set up by
303 .forward and filter files. Previously, any settings of the "file" or
304 "directory" options were ignored. It is hoped that, like the address_file
305 transport in the default configuration, these options were never in fact set
306 on such transports, because they were of no use.
308 Now, if either of these options is set, it is used. The path that is passed
309 by the router is in $address_file (this is not new), so it can be used as
310 part of a longer path, or modified in any other way that expansion permits.
312 If neither "file" nor "directory" is set, the behaviour is unchanged.
3144. Related to the above: in a filter, if a "save" command specifies a non-
315 absolute path, the value of $home/ is pre-pended. This no longer happens if
316 $home is unset or is set to an empty string.
3185. Multiple file deliveries from a filter or .forward file can never be
319 batched; the value of batch_max on the transport is ignored for file
320 deliveries. I'm assuming that nobody ever actually set batch_max on the
321 address_file transport - it would have had odd effects previously.
3236. DESTDIR is the more common variable that ROOT for use when installing
324 software under a different root filing system. The Exim install script now
325 recognizes DESTDIR first; if it is not set, ROOT is used.
3277. If DESTDIR is set when installing Exim, it no longer prepends its value to
328 the path of the system aliases file that appears in the default
329 configuration (when a default configuration is installed). If an aliases
330 file is actually created, its name *does* use the prefix.
333Version 4.14
3361. The default for the maximum number of unknown SMTP commands that Exim will
337accept before dropping a connection has been reduced from 5 to 3. However, you
338can now change the value by setting smtp_max_unknown_commands.
3402. The ${quote: operator has been changed so that it turns newline and carriage
341return characters into \n and \r, respectively.
3433. The file names used for maildir messages now include the microsecond time
344fraction as well as the time in seconds, to cope with systems where the process
345id can be re-used within the same second. The format is now
347 <time>.H<microsec>P<pid>.<host>
349This should be a compatible change, but is noted here just in case.
3514. The rules for creating message ids have changed, to cope with systems where
352the process id can be re-used within the same second. The format, however, is
353unchanged, so this should not cause any problems, except as noted in the next
3565. The maximum value for localhost_number has been reduced from 255 to 16, in
357order to implement the new message id rules. For operating systems that have
358case-insensitive file systems (Cygwin and Darwin), the limit is 10.
3606. verify = header_syntax was allowing unqualified addresses in all cases. Now
361it allows them only for locally generated messages and from hosts that match
362sender_unqualified_hosts or recipient_unqualified_hosts, respectively.
3647. For reasons lost in the mists of time, when a pipe transport was run, the
365environment variable MESSAGE_ID was set to the message ID preceded by 'E' (the
366form used in Message-ID: header lines). The 'E' has been removed.
369Version 4.11
3721. The handling of lines in the configuration file has changed. Previously,
373macro expansion was applied to logical lines, after continuations had been
374joined on. This meant that it could not be used in .include lines, which are
375handled as physical rather than logical lines. Macro expansion is now done on
376physical lines rather than logical lines. This means there are two
379 (a) A macro that expands to # to turn a line into a comment now applies only
380 to the physical line where it appears. Previously, it would have caused
381 any following continuations also to be ignored.
383 (b) A macro name can no longer be split over the boundary between a line and
384 its continuation. Actually, this is more of a bug fix. :-)
3862. The -D command line option must now all be within one command line item.
387This makes it possible to use -D to set a macro to the empty string by commands
388such as
390 exim -DABC ...
391 exim -DABC= ...
393Previously, these items would have moved on to the next item on the command
394line. To include spaces in a macro definition item, quotes must be used, in
395which case you can also have spaces after -D and surrounding the equals. For
398 exim '-D ABC = something' ...
4003. The way that addresses that redirect to themselves are handled has been
401changed, in order to fix an obscure bug. This should not cause any problems
402except in the case of wanting to go back from a 4.11 (or later) release to an
403earlier release. If there are undelivered messages on the spool that contain
404addresses which redirect to themselves, and the redirected addresses have
405already been delivered, you might get a duplicate delivery if you revert to an
406earlier Exim.
4084. The default way of looking up IP addresses for hosts in the manualroute and
409queryprogram routers has been changed. If "byname" or "bydns" is explicitly
410specified, there is no change, but if no method is specified, Exim now behaves
411as follows:
413 First, a DNS lookup is done. If this yields anything other than
414 HOST_NOT_FOUND, that result is used. Otherwise, Exim goes on to try a call to
415 getipnodebyname() (or gethostbyname() on older systems) and the result of the
416 lookup is the result of that call.
418This change has been made because it has been discovered that on some systems,
419if a DNS lookup called via getipnodebyname() times out, HOST_NOT_FOUND is
420returned instead of TRY_AGAIN. Thus, it is safest to try a DNS lookup directly
421first, and only if that gives a definite "no such host" to try the local
4245. In fixing the minor security problem with pid_file_path, I have removed some
425backwards-compatible (undocumented) code which was present to ease conversion
426from Exim 3. In Exim 4, pid_file_path is a literal; in Exim 3 it was allowed to
427contain "%s", which was replaced by the port number for daemons listening on
428non-standard ports. In Exim 4, such daemons do not write a pid file. The
429backwards compatibility feature was to replace "%s" by nothing if it occurred
430in an Exim 4 setting of pid_file_path. The bug was in this code. I have solved
431the problem by removing the backwards compatibility feature. Thus, if you still
432have "%s" somewhere in a setting of pid_file_path, you should remove it.
4346. There has been an extension to lsearch files. The keys in these files may
435now be quoted in order to allow for whitespace and colons in them. This means
436that if you were previously using keys that began with a doublequote, you will
437now have to wrap them with extra quotes and escape the internal quotes. The
438possibility that anybody is actually doing this seems extremely remote, but it
439is documented just in case.
442Version 4.10
445The build-time parameter EXIWHAT_KILL_ARG has been renamed EXIWHAT_KILL_SIGNAL
446to better reflect its function. The OS-specific files have been updated. Only
447if you have explicitly set this in your Makefile (highly unlikely) do you need
448to change anything.