1 $Cambridge: exim/doc/doc-txt/NewStuff,v 1.163 2010/06/01 11:13:54 pdp Exp $
6 This file contains descriptions of new features that have been added to Exim.
7 Before a formal release, there may be quite a lot of detail so that people can
8 test from the snapshots or the CVS before the documentation is updated. Once
9 the documentation is updated, this file is reduced to a short list.
15 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
16 writable, the other to locking of MBX folders (not mbox).
18 2. MySQL stored procedures are now supported.
20 3. The dkim_domain transport option is now a list, not a single string, and
21 messages will be signed for each element in the list (discarding
24 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
25 in the presence of multiple character strings within the RR. Prior to 4.70,
26 only the first string would be returned. The dnsdb lookup now, by default,
27 preserves the pre-4.70 semantics, but also now takes an extended output
28 separator specification. The first output separator is used to join
29 multiple TXT records together; use a second separator character, followed
30 by a colon, to join the strings within a TXT record on that second
31 character, or use a semicolon to concatenate strings within a TXT record
32 with no separator. Administrators are reminded that DNS provides no
33 ordering guarantees between multiple records in an RRset. For example:
35 foo.example. IN TXT "a" "b" "c"
36 foo.example. IN TXT "d" "e" "f"
38 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
39 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
40 ${lookup dnsdb{>/+: txt=foo.example}} -> "a+b+c/d+e+f"
42 Some character combinations are currently unsupported.
47 1. Native DKIM support without an external library.
49 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
51 3. There is now a bool{} expansion condition which maps certain strings to
52 true/false condition values (most likely of use in conjuction with the
53 and{} expansion operator).
55 4. The $spam_score, $spam_bar and $spam_report variables are now available
58 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
59 options, provided that Exim is invoked by an admin_user.
61 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
62 which increases compatibility with older clients at the cost of decreased
63 security. Don't set this unless you need to support such clients.
65 7. There is a new expansion operator, ${randint:...} which will produce a
66 "random" number less than the supplied integer. This randomness is
67 not guaranteed to be cryptographically strong, but depending upon how
68 Exim was built may be better than the most naive schemes.
70 8. Exim now explicitly ensures that SHA256 is available when linked against
73 9. The transport_filter_timeout option now applies to SMTP transports too.
79 1. The body_linecount and body_zerocount C variables are now exported in the
82 2. When a dnslists lookup succeeds, the key that was looked up is now placed
83 in $dnslist_matched. When the key is an IP address, it is not reversed in
84 this variable (though it is, of course, in the actual lookup). In simple
87 deny dnslists = spamhaus.example
89 the key is also available in another variable (in this case,
90 $sender_host_address). In more complicated cases, however, this is not
91 true. For example, using a data lookup might generate a dnslists lookup
94 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
96 If this condition succeeds, the value in $dnslist_matched might be
97 192.168.6.7 (for example).
99 3. Authenticators now have a client_condition option. When Exim is running as
100 a client, it skips an authenticator whose client_condition expansion yields
101 "0", "no", or "false". This can be used, for example, to skip plain text
102 authenticators when the connection is not encrypted by a setting such as:
104 client_condition = ${if !eq{$tls_cipher}{}}
106 Note that the 4.67 documentation states that $tls_cipher contains the
107 cipher used for incoming messages. In fact, during SMTP delivery, it
108 contains the cipher used for the delivery. The same is true for
111 4. There is now a -Mvc <message-id> option, which outputs a copy of the
112 message to the standard output, in RFC 2822 format. The option can be used
113 only by an admin user.
115 5. There is now a /noupdate option for the ratelimit ACL condition. It
116 computes the rate and checks the limit as normal, but it does not update
117 the saved data. This means that, in relevant ACLs, it is possible to lookup
118 the existence of a specified (or auto-generated) ratelimit key without
119 incrementing the ratelimit counter for that key.
121 In order for this to be useful, another ACL entry must set the rate
122 for the same key somewhere (otherwise it will always be zero).
127 # Read the rate; if it doesn't exist or is below the maximum
129 deny ratelimit = 100 / 5m / strict / noupdate
130 log_message = RATE: $sender_rate / $sender_rate_period \
131 (max $sender_rate_limit)
133 [... some other logic and tests...]
135 warn ratelimit = 100 / 5m / strict / per_cmd
136 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
137 (max $sender_rate_limit)
138 condition = ${if le{$sender_rate}{$sender_rate_limit}}
142 6. The variable $max_received_linelength contains the number of bytes in the
143 longest line that was received as part of the message, not counting the
144 line termination character(s).
146 7. Host lists can now include +ignore_defer and +include_defer, analagous to
147 +ignore_unknown and +include_unknown. These options should be used with
148 care, probably only in non-critical host lists such as whitelists.
150 8. There's a new option called queue_only_load_latch, which defaults true.
151 If set false when queue_only_load is greater than zero, Exim re-evaluates
152 the load for each incoming message in an SMTP session. Otherwise, once one
153 message is queued, the remainder are also.
155 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
156 cases when an SMTP session ends without sending QUIT. However, when Exim
157 itself is is bad trouble, such as being unable to write to its log files,
158 this ACL is not run, because it might try to do things (such as write to
159 log files) that make the situation even worse.
161 Like the QUIT ACL, this new ACL is provided to make it possible to gather
162 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
163 modifier is forbidden in this ACL.
165 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
166 to a string that indicates the reason for the termination of the SMTP
167 connection. The possible values are:
169 acl-drop Another ACL issued a "drop" command
170 bad-commands Too many unknown or non-mail commands
171 command-timeout Timeout while reading SMTP commands
172 connection-lost The SMTP connection has been lost
173 data-timeout Timeout while reading message data
174 local-scan-error The local_scan() function crashed
175 local-scan-timeout The local_scan() function timed out
176 signal-exit SIGTERM or SIGINT
177 synchronization-error SMTP synchronization error
178 tls-failed TLS failed to start
180 In most cases when an SMTP connection is closed without having received
181 QUIT, Exim sends an SMTP response message before actually closing the
182 connection. With the exception of acl-drop, the default message can be
183 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
184 "drop" verb in another ACL, it is the message from the other ACL that is
187 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
188 servers with individual queries. This is done by starting the query with
189 "servers=x:y:z;", where each item in the list may take one of two forms:
191 (1) If it is just a host name, the appropriate global option (mysql_servers
192 or pgsql_servers) is searched for a host of the same name, and the
193 remaining parameters (database, user, password) are taken from there.
195 (2) If it contains any slashes, it is taken as a complete parameter set.
197 The list of servers is used in exactly the same was as the global list.
198 Once a connection to a server has happened and a query has been
199 successfully executed, processing of the lookup ceases.
201 This feature is intended for use in master/slave situations where updates
202 are occurring, and one wants to update a master rather than a slave. If the
203 masters are in the list for reading, you might have:
205 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
207 In an updating lookup, you could then write
209 ${lookup mysql{servers=master; UPDATE ...}
211 If, on the other hand, the master is not to be used for reading lookups:
213 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
215 you can still update the master by
217 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
219 11. The message_body_newlines option (default FALSE, for backwards
220 compatibility) can be used to control whether newlines are present in
221 $message_body and $message_body_end. If it is FALSE, they are replaced by
228 1. There is a new log selector called smtp_no_mail, which is not included in
229 the default setting. When it is set, a line is written to the main log
230 whenever an accepted SMTP connection terminates without having issued a
233 2. When an item in a dnslists list is followed by = and & and a list of IP
234 addresses, the behaviour was not clear when the lookup returned more than
235 one IP address. This has been solved by the addition of == and =& for "all"
236 rather than the default "any" matching.
238 3. Up till now, the only control over which cipher suites GnuTLS uses has been
239 for the cipher algorithms. New options have been added to allow some of the
240 other parameters to be varied.
242 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
243 set, Exim compiles a runtime option called disable_fsync.
245 5. There is a new variable called $smtp_count_at_connection_start.
247 6. There's a new control called no_pipelining.
249 7. There are two new variables called $sending_ip_address and $sending_port.
250 These are set whenever an SMTP connection to another host has been set up.
252 8. The expansion of the helo_data option in the smtp transport now happens
253 after the connection to the server has been made.
255 9. There is a new expansion operator ${rfc2047d: that decodes strings that
256 are encoded as per RFC 2047.
258 10. There is a new log selector called "pid", which causes the current process
259 id to be added to every log line, in square brackets, immediately after the
262 11. Exim has been modified so that it flushes SMTP output before implementing
263 a delay in an ACL. It also flushes the output before performing a callout,
264 as this can take a substantial time. These behaviours can be disabled by
265 obeying control = no_delay_flush or control = no_callout_flush,
266 respectively, at some earlier stage of the connection.
268 12. There are two new expansion conditions that iterate over a list. They are
269 called forany and forall.
271 13. There's a new global option called dsn_from that can be used to vary the
272 contents of From: lines in bounces and other automatically generated
273 messages ("delivery status notifications" - hence the name of the option).
275 14. The smtp transport has a new option called hosts_avoid_pipelining.
277 15. By default, exigrep does case-insensitive matches. There is now a -I option
278 that makes it case-sensitive.
280 16. A number of new features ("addresses", "map", "filter", and "reduce") have
281 been added to string expansions to make it easier to process lists of
282 items, typically addresses.
284 17. There's a new ACL modifier called "continue". It does nothing of itself,
285 and processing of the ACL always continues with the next condition or
286 modifier. It is provided so that the side effects of expanding its argument
289 18. It is now possible to use newline and other control characters (those with
290 values less than 32, plus DEL) as separators in lists.
292 19. The exigrep utility now has a -v option, which inverts the matching
295 20. The host_find_failed option in the manualroute router can now be set to
302 No new features were added to 4.66.
308 No new features were added to 4.65.
314 1. ACL variables can now be given arbitrary names, as long as they start with
315 "acl_c" or "acl_m" (for connection variables and message variables), are at
316 least six characters long, with the sixth character being either a digit or
319 2. There is a new ACL modifier called log_reject_target. It makes it possible
320 to specify which logs are used for messages about ACL rejections.
322 3. There is a new authenticator called "dovecot". This is an interface to the
323 authentication facility of the Dovecot POP/IMAP server, which can support a
324 number of authentication methods.
326 4. The variable $message_headers_raw provides a concatenation of all the
327 messages's headers without any decoding. This is in contrast to
328 $message_headers, which does RFC2047 decoding on the header contents.
330 5. In a DNS black list, if two domain names, comma-separated, are given, the
331 second is used first to do an initial check, making use of any IP value
332 restrictions that are set. If there is a match, the first domain is used,
333 without any IP value restrictions, to get the TXT record.
335 6. All authenticators now have a server_condition option.
337 7. There is a new command-line option called -Mset. It is useful only in
338 conjunction with -be (that is, when testing string expansions). It must be
339 followed by a message id; Exim loads the given message from its spool
340 before doing the expansions.
342 8. Another similar new command-line option is called -bem. It operates like
343 -be except that it must be followed by the name of a file that contains a
346 9. When an address is delayed because of a 4xx response to a RCPT command, it
347 is now the combination of sender and recipient that is delayed in
348 subsequent queue runs until its retry time is reached.
350 10. Unary negation and the bitwise logical operators and, or, xor, not, and
351 shift, have been added to the eval: and eval10: expansion items.
353 11. The variables $interface_address and $interface_port have been renamed
354 as $received_ip_address and $received_port, to make it clear that they
355 relate to message reception rather than delivery. (The old names remain
356 available for compatibility.)
358 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
359 to vary the message that is sent when an SMTP command is accepted.
365 1. There is a new Boolean option called filter_prepend_home for the redirect
368 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
369 start of receiving a non-SMTP message, before any of the message has been
372 3. When an SMTP error message is specified in a "message" modifier in an ACL,
373 or in a :fail: or :defer: message in a redirect router, Exim now checks the
374 start of the message for an SMTP error code.
376 4. There is a new parameter for LDAP lookups called "referrals", which takes
377 one of the settings "follow" (the default) or "nofollow".
379 5. Version 20070721.2 of exipick now included, offering these new options:
381 After all other sorting options have bee processed, reverse order
382 before displaying messages (-R is synonym).
384 Randomize order of matching messages before displaying.
386 Instead of displaying the matching messages, display the sum
388 --sort <variable>[,<variable>...]
389 Before displaying matching messages, sort the messages according to
390 each messages value for each variable.
392 Negate the value for every test (returns inverse output from the
393 same criteria without --not).
399 1. The ${readsocket expansion item now supports Internet domain sockets as well
400 as Unix domain sockets. If the first argument begins "inet:", it must be of
401 the form "inet:host:port". The port is mandatory; it may be a number or the
402 name of a TCP port in /etc/services. The host may be a name, or it may be an
403 IP address. An ip address may optionally be enclosed in square brackets.
404 This is best for IPv6 addresses. For example:
406 ${readsocket{inet:[::1]:1234}{<request data>}...
408 Only a single host name may be given, but if looking it up yield more than
409 one IP address, they are each tried in turn until a connection is made. Once
410 a connection has been made, the behaviour is as for ${readsocket with a Unix
413 2. If a redirect router sets up file or pipe deliveries for more than one
414 incoming address, and the relevant transport has batch_max set greater than
415 one, a batch delivery now occurs.
417 3. The appendfile transport has a new option called maildirfolder_create_regex.
418 Its value is a regular expression. For a maildir delivery, this is matched
419 against the maildir directory; if it matches, Exim ensures that a
420 maildirfolder file is created alongside the new, cur, and tmp directories.
426 The documentation is up-to-date for the 4.61 release. Major new features since
427 the 4.60 release are:
429 . An option called disable_ipv6, to disable the use of IPv6 completely.
431 . An increase in the number of ACL variables to 20 of each type.
433 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
434 $2, $3, (though those are still set) because the numeric variables get used
435 for other things in complicated expansions.
437 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
439 . It is possible to use setclassresources() on some BSD OS to control the
440 resources used in pipe deliveries.
442 . A new ACL modifier called add_header, which can be used with any verb.
444 . More errors are detectable in retry rules.
446 There are a number of other additions too.
452 The documentation is up-to-date for the 4.60 release. Major new features since
453 the 4.50 release are:
455 . Support for SQLite.
457 . Support for IGNOREQUOTA in LMTP.
459 . Extensions to the "submission mode" features.
461 . Support for Client SMTP Authorization (CSA).
463 . Support for ratelimiting hosts and users.
465 . New expansion items to help with the BATV "prvs" scheme.
467 . A "match_ip" condition, that matches an IP address against a list.
469 There are many more minor changes.