1 $Cambridge: exim/doc/doc-txt/NewStuff,v 1.166 2010/06/05 09:10:09 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. A new main configuration option, "openssl_options", is available if Exim
16 is built with SSL support provided by OpenSSL. The option allows
17 administrators to specify OpenSSL options to be used on connections;
18 typically this is to set bug compatibility features which the OpenSSL
19 developers have not enabled by default. There may be security
20 consequences for certain options, so these should not be changed
27 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
28 writable, the other to locking of MBX folders (not mbox).
30 2. MySQL stored procedures are now supported.
32 3. The dkim_domain transport option is now a list, not a single string, and
33 messages will be signed for each element in the list (discarding
36 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
37 in the presence of multiple character strings within the RR. Prior to 4.70,
38 only the first string would be returned. The dnsdb lookup now, by default,
39 preserves the pre-4.70 semantics, but also now takes an extended output
40 separator specification. The separator can be followed by a semicolon, to
41 concatenate the individual text strings together with no join character,
42 or by a comma and a second separator character, in which case the text
43 strings within a TXT record are joined on that second character.
44 Administrators are reminded that DNS provides no ordering guarantees
45 between multiple records in an RRset. For example:
47 foo.example. IN TXT "a" "b" "c"
48 foo.example. IN TXT "d" "e" "f"
50 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
51 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
52 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
58 1. Native DKIM support without an external library.
59 (Note that if no action to prevent it is taken, a straight upgrade will
60 result in DKIM verification of all signed incoming emails. See spec
61 for details on conditionally disabling)
63 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
65 3. There is now a bool{} expansion condition which maps certain strings to
66 true/false condition values (most likely of use in conjuction with the
67 and{} expansion operator).
69 4. The $spam_score, $spam_bar and $spam_report variables are now available
72 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
73 options, provided that Exim is invoked by an admin_user.
75 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
76 which increases compatibility with older clients at the cost of decreased
77 security. Don't set this unless you need to support such clients.
79 7. There is a new expansion operator, ${randint:...} which will produce a
80 "random" number less than the supplied integer. This randomness is
81 not guaranteed to be cryptographically strong, but depending upon how
82 Exim was built may be better than the most naive schemes.
84 8. Exim now explicitly ensures that SHA256 is available when linked against
87 9. The transport_filter_timeout option now applies to SMTP transports too.
93 1. The body_linecount and body_zerocount C variables are now exported in the
96 2. When a dnslists lookup succeeds, the key that was looked up is now placed
97 in $dnslist_matched. When the key is an IP address, it is not reversed in
98 this variable (though it is, of course, in the actual lookup). In simple
101 deny dnslists = spamhaus.example
103 the key is also available in another variable (in this case,
104 $sender_host_address). In more complicated cases, however, this is not
105 true. For example, using a data lookup might generate a dnslists lookup
108 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
110 If this condition succeeds, the value in $dnslist_matched might be
111 192.168.6.7 (for example).
113 3. Authenticators now have a client_condition option. When Exim is running as
114 a client, it skips an authenticator whose client_condition expansion yields
115 "0", "no", or "false". This can be used, for example, to skip plain text
116 authenticators when the connection is not encrypted by a setting such as:
118 client_condition = ${if !eq{$tls_cipher}{}}
120 Note that the 4.67 documentation states that $tls_cipher contains the
121 cipher used for incoming messages. In fact, during SMTP delivery, it
122 contains the cipher used for the delivery. The same is true for
125 4. There is now a -Mvc <message-id> option, which outputs a copy of the
126 message to the standard output, in RFC 2822 format. The option can be used
127 only by an admin user.
129 5. There is now a /noupdate option for the ratelimit ACL condition. It
130 computes the rate and checks the limit as normal, but it does not update
131 the saved data. This means that, in relevant ACLs, it is possible to lookup
132 the existence of a specified (or auto-generated) ratelimit key without
133 incrementing the ratelimit counter for that key.
135 In order for this to be useful, another ACL entry must set the rate
136 for the same key somewhere (otherwise it will always be zero).
141 # Read the rate; if it doesn't exist or is below the maximum
143 deny ratelimit = 100 / 5m / strict / noupdate
144 log_message = RATE: $sender_rate / $sender_rate_period \
145 (max $sender_rate_limit)
147 [... some other logic and tests...]
149 warn ratelimit = 100 / 5m / strict / per_cmd
150 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
151 (max $sender_rate_limit)
152 condition = ${if le{$sender_rate}{$sender_rate_limit}}
156 6. The variable $max_received_linelength contains the number of bytes in the
157 longest line that was received as part of the message, not counting the
158 line termination character(s).
160 7. Host lists can now include +ignore_defer and +include_defer, analagous to
161 +ignore_unknown and +include_unknown. These options should be used with
162 care, probably only in non-critical host lists such as whitelists.
164 8. There's a new option called queue_only_load_latch, which defaults true.
165 If set false when queue_only_load is greater than zero, Exim re-evaluates
166 the load for each incoming message in an SMTP session. Otherwise, once one
167 message is queued, the remainder are also.
169 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
170 cases when an SMTP session ends without sending QUIT. However, when Exim
171 itself is is bad trouble, such as being unable to write to its log files,
172 this ACL is not run, because it might try to do things (such as write to
173 log files) that make the situation even worse.
175 Like the QUIT ACL, this new ACL is provided to make it possible to gather
176 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
177 modifier is forbidden in this ACL.
179 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
180 to a string that indicates the reason for the termination of the SMTP
181 connection. The possible values are:
183 acl-drop Another ACL issued a "drop" command
184 bad-commands Too many unknown or non-mail commands
185 command-timeout Timeout while reading SMTP commands
186 connection-lost The SMTP connection has been lost
187 data-timeout Timeout while reading message data
188 local-scan-error The local_scan() function crashed
189 local-scan-timeout The local_scan() function timed out
190 signal-exit SIGTERM or SIGINT
191 synchronization-error SMTP synchronization error
192 tls-failed TLS failed to start
194 In most cases when an SMTP connection is closed without having received
195 QUIT, Exim sends an SMTP response message before actually closing the
196 connection. With the exception of acl-drop, the default message can be
197 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
198 "drop" verb in another ACL, it is the message from the other ACL that is
201 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
202 servers with individual queries. This is done by starting the query with
203 "servers=x:y:z;", where each item in the list may take one of two forms:
205 (1) If it is just a host name, the appropriate global option (mysql_servers
206 or pgsql_servers) is searched for a host of the same name, and the
207 remaining parameters (database, user, password) are taken from there.
209 (2) If it contains any slashes, it is taken as a complete parameter set.
211 The list of servers is used in exactly the same was as the global list.
212 Once a connection to a server has happened and a query has been
213 successfully executed, processing of the lookup ceases.
215 This feature is intended for use in master/slave situations where updates
216 are occurring, and one wants to update a master rather than a slave. If the
217 masters are in the list for reading, you might have:
219 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
221 In an updating lookup, you could then write
223 ${lookup mysql{servers=master; UPDATE ...}
225 If, on the other hand, the master is not to be used for reading lookups:
227 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
229 you can still update the master by
231 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
233 11. The message_body_newlines option (default FALSE, for backwards
234 compatibility) can be used to control whether newlines are present in
235 $message_body and $message_body_end. If it is FALSE, they are replaced by
242 1. There is a new log selector called smtp_no_mail, which is not included in
243 the default setting. When it is set, a line is written to the main log
244 whenever an accepted SMTP connection terminates without having issued a
247 2. When an item in a dnslists list is followed by = and & and a list of IP
248 addresses, the behaviour was not clear when the lookup returned more than
249 one IP address. This has been solved by the addition of == and =& for "all"
250 rather than the default "any" matching.
252 3. Up till now, the only control over which cipher suites GnuTLS uses has been
253 for the cipher algorithms. New options have been added to allow some of the
254 other parameters to be varied.
256 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
257 set, Exim compiles a runtime option called disable_fsync.
259 5. There is a new variable called $smtp_count_at_connection_start.
261 6. There's a new control called no_pipelining.
263 7. There are two new variables called $sending_ip_address and $sending_port.
264 These are set whenever an SMTP connection to another host has been set up.
266 8. The expansion of the helo_data option in the smtp transport now happens
267 after the connection to the server has been made.
269 9. There is a new expansion operator ${rfc2047d: that decodes strings that
270 are encoded as per RFC 2047.
272 10. There is a new log selector called "pid", which causes the current process
273 id to be added to every log line, in square brackets, immediately after the
276 11. Exim has been modified so that it flushes SMTP output before implementing
277 a delay in an ACL. It also flushes the output before performing a callout,
278 as this can take a substantial time. These behaviours can be disabled by
279 obeying control = no_delay_flush or control = no_callout_flush,
280 respectively, at some earlier stage of the connection.
282 12. There are two new expansion conditions that iterate over a list. They are
283 called forany and forall.
285 13. There's a new global option called dsn_from that can be used to vary the
286 contents of From: lines in bounces and other automatically generated
287 messages ("delivery status notifications" - hence the name of the option).
289 14. The smtp transport has a new option called hosts_avoid_pipelining.
291 15. By default, exigrep does case-insensitive matches. There is now a -I option
292 that makes it case-sensitive.
294 16. A number of new features ("addresses", "map", "filter", and "reduce") have
295 been added to string expansions to make it easier to process lists of
296 items, typically addresses.
298 17. There's a new ACL modifier called "continue". It does nothing of itself,
299 and processing of the ACL always continues with the next condition or
300 modifier. It is provided so that the side effects of expanding its argument
303 18. It is now possible to use newline and other control characters (those with
304 values less than 32, plus DEL) as separators in lists.
306 19. The exigrep utility now has a -v option, which inverts the matching
309 20. The host_find_failed option in the manualroute router can now be set to
316 No new features were added to 4.66.
322 No new features were added to 4.65.
328 1. ACL variables can now be given arbitrary names, as long as they start with
329 "acl_c" or "acl_m" (for connection variables and message variables), are at
330 least six characters long, with the sixth character being either a digit or
333 2. There is a new ACL modifier called log_reject_target. It makes it possible
334 to specify which logs are used for messages about ACL rejections.
336 3. There is a new authenticator called "dovecot". This is an interface to the
337 authentication facility of the Dovecot POP/IMAP server, which can support a
338 number of authentication methods.
340 4. The variable $message_headers_raw provides a concatenation of all the
341 messages's headers without any decoding. This is in contrast to
342 $message_headers, which does RFC2047 decoding on the header contents.
344 5. In a DNS black list, if two domain names, comma-separated, are given, the
345 second is used first to do an initial check, making use of any IP value
346 restrictions that are set. If there is a match, the first domain is used,
347 without any IP value restrictions, to get the TXT record.
349 6. All authenticators now have a server_condition option.
351 7. There is a new command-line option called -Mset. It is useful only in
352 conjunction with -be (that is, when testing string expansions). It must be
353 followed by a message id; Exim loads the given message from its spool
354 before doing the expansions.
356 8. Another similar new command-line option is called -bem. It operates like
357 -be except that it must be followed by the name of a file that contains a
360 9. When an address is delayed because of a 4xx response to a RCPT command, it
361 is now the combination of sender and recipient that is delayed in
362 subsequent queue runs until its retry time is reached.
364 10. Unary negation and the bitwise logical operators and, or, xor, not, and
365 shift, have been added to the eval: and eval10: expansion items.
367 11. The variables $interface_address and $interface_port have been renamed
368 as $received_ip_address and $received_port, to make it clear that they
369 relate to message reception rather than delivery. (The old names remain
370 available for compatibility.)
372 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
373 to vary the message that is sent when an SMTP command is accepted.
379 1. There is a new Boolean option called filter_prepend_home for the redirect
382 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
383 start of receiving a non-SMTP message, before any of the message has been
386 3. When an SMTP error message is specified in a "message" modifier in an ACL,
387 or in a :fail: or :defer: message in a redirect router, Exim now checks the
388 start of the message for an SMTP error code.
390 4. There is a new parameter for LDAP lookups called "referrals", which takes
391 one of the settings "follow" (the default) or "nofollow".
393 5. Version 20070721.2 of exipick now included, offering these new options:
395 After all other sorting options have bee processed, reverse order
396 before displaying messages (-R is synonym).
398 Randomize order of matching messages before displaying.
400 Instead of displaying the matching messages, display the sum
402 --sort <variable>[,<variable>...]
403 Before displaying matching messages, sort the messages according to
404 each messages value for each variable.
406 Negate the value for every test (returns inverse output from the
407 same criteria without --not).
413 1. The ${readsocket expansion item now supports Internet domain sockets as well
414 as Unix domain sockets. If the first argument begins "inet:", it must be of
415 the form "inet:host:port". The port is mandatory; it may be a number or the
416 name of a TCP port in /etc/services. The host may be a name, or it may be an
417 IP address. An ip address may optionally be enclosed in square brackets.
418 This is best for IPv6 addresses. For example:
420 ${readsocket{inet:[::1]:1234}{<request data>}...
422 Only a single host name may be given, but if looking it up yield more than
423 one IP address, they are each tried in turn until a connection is made. Once
424 a connection has been made, the behaviour is as for ${readsocket with a Unix
427 2. If a redirect router sets up file or pipe deliveries for more than one
428 incoming address, and the relevant transport has batch_max set greater than
429 one, a batch delivery now occurs.
431 3. The appendfile transport has a new option called maildirfolder_create_regex.
432 Its value is a regular expression. For a maildir delivery, this is matched
433 against the maildir directory; if it matches, Exim ensures that a
434 maildirfolder file is created alongside the new, cur, and tmp directories.
440 The documentation is up-to-date for the 4.61 release. Major new features since
441 the 4.60 release are:
443 . An option called disable_ipv6, to disable the use of IPv6 completely.
445 . An increase in the number of ACL variables to 20 of each type.
447 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
448 $2, $3, (though those are still set) because the numeric variables get used
449 for other things in complicated expansions.
451 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
453 . It is possible to use setclassresources() on some BSD OS to control the
454 resources used in pipe deliveries.
456 . A new ACL modifier called add_header, which can be used with any verb.
458 . More errors are detectable in retry rules.
460 There are a number of other additions too.
466 The documentation is up-to-date for the 4.60 release. Major new features since
467 the 4.50 release are:
469 . Support for SQLite.
471 . Support for IGNOREQUOTA in LMTP.
473 . Extensions to the "submission mode" features.
475 . Support for Client SMTP Authorization (CSA).
477 . Support for ratelimiting hosts and users.
479 . New expansion items to help with the BATV "prvs" scheme.
481 . A "match_ip" condition, that matches an IP address against a list.
483 There are many more minor changes.