d1d0d7279c8664095a1b791c0e14974f0975beea
[exim.git] / doc / doc-txt / NewStuff
1 New Features in Exim
2 --------------------
3
4 This file contains descriptions of new features that have been added to Exim.
5 Before a formal release, there may be quite a lot of detail so that people can
6 test from the snapshots or the CVS before the documentation is updated. Once
7 the documentation is updated, this file is reduced to a short list.
8
9 Version 4.82
10 ------------
11
12 1. New command-line option -bI:sieve will list all supported sieve extensions
13 of this Exim build on standard output, one per line.
14 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
15 query this to establish the correct list to include in the protocol's
16 SIEVE capability line.
17
18 2. If the -n option is combined with the -bP option, then the name of an
19 emitted option is not output, only the value (if visible to you).
20 For instance, "exim -n -bP pid_file_path" should just emit a pathname
21 followed by a newline, and no other text.
22
23 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
24 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
25 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
26 acceptable for security. (Option accepted but ignored if using OpenSSL).
27 Defaults to 1024, the old value. May be lowered only to 512, or raised as
28 far as you like. Raising this may hinder TLS interoperability with other
29 sites and is not currently recommended. Lowering this will permit you to
30 establish a TLS session which is not as secure as you might like.
31
32 Unless you really know what you are doing, leave it alone.
33
34 4. If not built with DISABLE_DNSSEC, Exim now has the main option
35 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
36 to send the DO flag to your recursive resolver. If you have a recursive
37 resolver, which can set the Authenticated Data (AD) flag in results, Exim
38 can now detect this. Exim does not perform validation itself, instead
39 relying upon a trusted path to the resolver.
40
41 Current status: work-in-progress; $sender_host_dnssec variable added.
42
43 5. DSCP support for outbound connections: on a transport using the smtp driver,
44 set "dscp = ef", for instance, to cause the connections to have the relevant
45 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
46
47 Similarly for inbound connections, there is a new control modifier, dscp,
48 so "warn control = dscp/ef" in the connect ACL, or after authentication.
49
50 Supported values depend upon system libraries. "exim -bI:dscp" to list the
51 ones Exim knows of. You can also set a raw number 0..0x3F.
52
53 6. The -G command-line flag is no longer ignored; it is now equivalent to an
54 ACL setting "control = suppress_local_fixups". The -L command-line flag
55 is now accepted and forces use of syslog, with the provided tag as the
56 process name. A few other flags used by Sendmail are now accepted and
57 ignored.
58
59 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
60 ACL modifier; works for single-recipient mails which are recieved on and
61 deliverable via SMTP. Using the connection made for a recipient verify,
62 if requested before the verify, or a new one made for the purpose while
63 the inbound connection is still active. The bulk of the mail item is copied
64 direct from the inbound socket to the outbound (as well as the spool file).
65 When the source notifies the end of data, the data acceptance by the destination
66 is negociated before the acceptance is sent to the source. If the destination
67 does not accept the mail item, for example due to content-scanning, the item
68 is not accepted from the source and therefore there is no need to generate
69 a bounce mail. This is of benefit when providing a secondary-MX service.
70 The downside is that delays are under the control of the ultimate destination
71 system not your own.
72
73 The Recieved-by: header on items delivered by cutthrough is generated
74 early in reception rather than at the end; this will affect any timestamp
75 included. The log line showing delivery is recorded before that showing
76 reception; it uses a new ">>" tag instead of "=>".
77
78 To support the feature, verify-callout connections can now use ESMTP and TLS.
79 The usual smtp transport options are honoured, plus a (new, default everything)
80 hosts_verify_avoid_tls.
81
82 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
83 for specific access to the information for each connection. The old names
84 are present for now but deprecated.
85
86 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
87
88 8. New expansion operators ${listnamed:name} to get the content of a named list
89 and ${listcount:string} to count the items in a list.
90
91 9. New global option "gnutls_enable_pkcs11", defaults false. The GnuTLS
92 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
93 modules. For some situations this is desirable, but we expect admin in
94 those situations to know they want the feature. More commonly, it means
95 that GUI user modules get loaded and are broken by the setuid Exim being
96 unable to access files specified in environment variables and passed
97 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
98 unless this new option is set.
99
100 10. The "acl = name" condition on an ACL now supports optional arguments.
101 New expansion item "${acl {name}{arg}...}" and expansion condition
102 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
103 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
104 Variable $acl_narg contains the number of arguments. If the ACL sets
105 a "message =" value this becomes the result of the expansion item,
106 or the value of $value for the expansion condition. If the ACL returns
107 accept the expansion condition is true; if reject, false. A defer
108 return results in a forced fail.
109
110 11. Routers and transports can now have multiple headers_add and headers_remove
111 option lines. The concatenated list is used.
112
113 12. New ACL modifier "remove_header" can remove headers before message gets
114 handled by routers/transports.
115
116 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
117 "aaaa" and "a" lookups is done and the full set of results returned.
118
119 14. New expansion variable $headers_added with content from ACL add_header
120 modifier (but not yet added to messsage).
121
122 15. New 8bitmime status logging option for received messages. Log field "M8S".
123
124 16. New authenticated_sender logging option, adding to log field "A".
125
126 17. New expansion variables $router_name and $transport_name. Useful
127 particularly for debug_print as -bt commandline option does not
128 require privilege whereas -d does.
129
130 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
131 proposed extension to SMTP from Eric Hall.
132
133 19. The pipe transport has gained the force_command option, to allow
134 decorating commands from user .forward pipe aliases with prefix
135 wrappers, for instance.
136
137 20. Callout connections can now AUTH; the same controls as normal delivery
138 connections apply.
139
140
141 Version 4.80
142 ------------
143
144 1. New authenticator driver, "gsasl". Server-only (at present).
145 This is a SASL interface, licensed under GPL, which can be found at
146 http://www.gnu.org/software/gsasl/.
147 This system does not provide sources of data for authentication, so
148 careful use needs to be made of the conditions in Exim.
149
150 2. New authenticator driver, "heimdal_gssapi". Server-only.
151 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
152 is no longer honoured for setuid programs by Heimdal. Use the
153 "server_keytab" option to point to the keytab.
154
155 3. The "pkg-config" system can now be used when building Exim to reference
156 cflags and library information for lookups and authenticators, rather
157 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
158 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
159 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
160
161 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
162 find the headers and libraries for PCRE.
163
164 4. New expansion variable $tls_bits.
165
166 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
167 be joined together with ASCII NUL characters to construct the key to pass
168 into the DBM library. Can be used with gsasl to access sasldb2 files as
169 used by Cyrus SASL.
170
171 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
172
173 Avoid release 1.0.1a if you can. Note that the default value of
174 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
175 increased susceptibility to attack. This may still have interoperability
176 implications for very old clients (see version 4.31 change 37) but
177 administrators can choose to make the trade-off themselves and restore
178 compatibility at the cost of session security.
179
180 7. Use of the new expansion variable $tls_sni in the main configuration option
181 tls_certificate will cause Exim to re-expand the option, if the client
182 sends the TLS Server Name Indication extension, to permit choosing a
183 different certificate; tls_privatekey will also be re-expanded. You must
184 still set these options to expand to valid files when $tls_sni is not set.
185
186 The SMTP Transport has gained the option tls_sni, which will set a hostname
187 for outbound TLS sessions, and set $tls_sni too.
188
189 A new log_selector, +tls_sni, has been added, to log received SNI values
190 for Exim as a server.
191
192 8. The existing "accept_8bitmime" option now defaults to true. This means
193 that Exim is deliberately not strictly RFC compliant. We're following
194 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
195 Those who disagree, or know that they are talking to mail servers that,
196 even today, are not 8-bit clean, need to turn off this option.
197
198 9. Exim can now be started with -bw (with an optional timeout, given as
199 -bw<timespec>). With this, stdin at startup is a socket that is
200 already listening for connections. This has a more modern name of
201 "socket activation", but forcing the activated socket to fd 0. We're
202 interested in adding more support for modern variants.
203
204 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
205 for numbers indicates multiplication by 1024^3.
206
207 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
208 gnutls_require_mac & gnutls_require_protocols are no longer supported.
209 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
210 string, documentation for which is at:
211 http://www.gnu.org/software/gnutls/manual/html_node/Priority-Strings.html
212
213 SNI support has been added to Exim's GnuTLS integration too.
214
215 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
216 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
217
218 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
219 is now available. If the contents of the file are valid, then Exim will
220 send that back in response to a TLS status request; this is OCSP Stapling.
221 Exim will not maintain the contents of the file in any way: administrators
222 are responsible for ensuring that it is up-to-date.
223
224 See "experimental-spec.txt" for more details.
225
226 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
227 identically to TXT record lookups.
228
229 14. New expansion variable $tod_epoch_l for higher-precision time.
230
231 15. New global option tls_dh_max_bits, defaulting to current value of NSS
232 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
233 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
234
235 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
236 Option can now be a path or an identifier for a standard prime.
237 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
238 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
239 primes.
240
241 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
242 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
243 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
244
245
246 Version 4.77
247 ------------
248
249 1. New options for the ratelimit ACL condition: /count= and /unique=.
250 The /noupdate option has been replaced by a /readonly option.
251
252 2. The SMTP transport's protocol option may now be set to "smtps", to
253 use SSL-on-connect outbound.
254
255 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
256 there is a problem talking to the AV scanner, or the AV scanner running.
257
258 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
259 and check if the search item is a member of the list. This does not
260 support named lists, but does subject the list part to string expansion.
261
262 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
263 built, Exim no longer performs string expansion on the second string of
264 the match_* expansion conditions: "match_address", "match_domain",
265 "match_ip" & "match_local_part". Named lists can still be used.
266
267
268 Version 4.76
269 ------------
270
271 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
272 or off in the resolver library.
273
274
275 Version 4.75
276 ------------
277
278 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
279 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
280 libraries. The following global options have been added in support of
281 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
282 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
283
284 2. The pipe transport now takes a boolean option, "freeze_signal", default
285 false. When true, if the external delivery command exits on a signal then
286 Exim will freeze the message in the queue, instead of generating a bounce.
287
288 3. Log filenames may now use %M as an escape, instead of %D (still available).
289 The %M pattern expands to yyyymm, providing month-level resolution.
290
291 4. The $message_linecount variable is now updated for the maildir_tag option,
292 in the same way as $message_size, to reflect the real number of lines,
293 including any header additions or removals from transport.
294
295 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
296 Exim now selects entries randomly, to better scale in a cluster setup.
297
298
299 Version 4.74
300 ------------
301
302 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
303 the flaw permitted the Exim run-time user to cause root to append to
304 arbitrary files of the attacker's choosing, with the content based
305 on content supplied by the attacker.
306
307 2. Exim now supports loading some lookup types at run-time, using your
308 platform's dlopen() functionality. This has limited platform support
309 and the intention is not to support every variant, it's limited to
310 dlopen(). This permits the main Exim binary to not be linked against
311 all the libraries needed for all the lookup types.
312
313
314 Version 4.73
315 ------------
316
317 NOTE: this version is not guaranteed backwards-compatible, please read the
318 items below carefully
319
320 1. A new main configuration option, "openssl_options", is available if Exim
321 is built with SSL support provided by OpenSSL. The option allows
322 administrators to specify OpenSSL options to be used on connections;
323 typically this is to set bug compatibility features which the OpenSSL
324 developers have not enabled by default. There may be security
325 consequences for certain options, so these should not be changed
326 frivolously.
327
328 2. A new pipe transport option, "permit_coredumps", may help with problem
329 diagnosis in some scenarios. Note that Exim is typically installed as
330 a setuid binary, which on most OSes will inhibit coredumps by default,
331 so that safety mechanism would have to be overridden for this option to
332 be able to take effect.
333
334 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
335 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
336 Note that this switches Exim to use a new API ("INSTREAM") and a future
337 release of ClamAV will remove support for the old API ("STREAM").
338
339 The av_scanner option, when set to "clamd", now takes an optional third
340 part, "local", which causes Exim to pass a filename to ClamAV instead of
341 the file content. This is the same behaviour as when clamd is pointed at
342 a Unix-domain socket. For example:
343
344 av_scanner = clamd:192.0.2.3 1234:local
345
346 ClamAV's ExtendedDetectionInfo response format is now handled.
347
348 4. There is now a -bmalware option, restricted to admin users. This option
349 takes one parameter, a filename, and scans that file with Exim's
350 malware-scanning framework. This is intended purely as a debugging aid
351 to ensure that Exim's scanning is working, not to replace other tools.
352 Note that the ACL framework is not invoked, so if av_scanner references
353 ACL variables without a fallback then this will fail.
354
355 5. There is a new expansion operator, "reverse_ip", which will reverse IP
356 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
357
358 ${reverse_ip:192.0.2.4}
359 -> 4.2.0.192
360 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
361 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
362
363 6. There is a new ACL control called "debug", to enable debug logging.
364 This allows selective logging of certain incoming transactions within
365 production environments, with some care. It takes two options, "tag"
366 and "opts"; "tag" is included in the filename of the log and "opts"
367 is used as per the -d<options> command-line option. Examples, which
368 don't all make sense in all contexts:
369
370 control = debug
371 control = debug/tag=.$sender_host_address
372 control = debug/opts=+expand+acl
373 control = debug/tag=.$message_exim_id/opts=+expand
374
375 7. It has always been implicit in the design and the documentation that
376 "the Exim user" is not root. src/EDITME said that using root was
377 "very strongly discouraged". This is not enough to keep people from
378 shooting themselves in the foot in days when many don't configure Exim
379 themselves but via package build managers. The security consequences of
380 running various bits of network code are severe if there should be bugs in
381 them. As such, the Exim user may no longer be root. If configured
382 statically, Exim will refuse to build. If configured as ref:user then Exim
383 will exit shortly after start-up. If you must shoot yourself in the foot,
384 then henceforth you will have to maintain your own local patches to strip
385 the safeties off.
386
387 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
388 condition logic to determine truth/failure and will fail to expand many
389 strings, bool_lax{} uses the router condition logic, where most strings
390 do evaluate true.
391 Note: bool{00} is false, bool_lax{00} is true.
392
393 9. Routers now support multiple "condition" tests.
394
395 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
396 Setting this allows an admin to define which entry in the tcpwrappers
397 config file will be used to control access to the daemon. This option
398 is only available when Exim is built with USE_TCP_WRAPPERS. The
399 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
400 build option.
401
402 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
403 the Exim run-time user, instead of root.
404
405 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
406 is forced on. This is mitigated by the new build option
407 TRUSTED_CONFIG_LIST which defines a list of configuration files which
408 are trusted; one per line. If a config file is owned by root and matches
409 a pathname in the list, then it may be invoked by the Exim build-time
410 user without Exim relinquishing root privileges.
411
412 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
413 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
414 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
415 include the main config. As a transition mechanism, we are temporarily
416 providing a work-around: the new build option WHITELIST_D_MACROS provides
417 a colon-separated list of macro names which may be overridden by the Exim
418 run-time user. The values of these macros are constrained to the regex
419 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
420
421
422 Version 4.72
423 ------------
424
425 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
426 writable, the other to locking of MBX folders (not mbox).
427
428 2. MySQL stored procedures are now supported.
429
430 3. The dkim_domain transport option is now a list, not a single string, and
431 messages will be signed for each element in the list (discarding
432 duplicates).
433
434 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
435 in the presence of multiple character strings within the RR. Prior to 4.70,
436 only the first string would be returned. The dnsdb lookup now, by default,
437 preserves the pre-4.70 semantics, but also now takes an extended output
438 separator specification. The separator can be followed by a semicolon, to
439 concatenate the individual text strings together with no join character,
440 or by a comma and a second separator character, in which case the text
441 strings within a TXT record are joined on that second character.
442 Administrators are reminded that DNS provides no ordering guarantees
443 between multiple records in an RRset. For example:
444
445 foo.example. IN TXT "a" "b" "c"
446 foo.example. IN TXT "d" "e" "f"
447
448 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
449 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
450 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
451
452
453 Version 4.70 / 4.71
454 -------------------
455
456 1. Native DKIM support without an external library.
457 (Note that if no action to prevent it is taken, a straight upgrade will
458 result in DKIM verification of all signed incoming emails. See spec
459 for details on conditionally disabling)
460
461 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
462
463 3. There is now a bool{} expansion condition which maps certain strings to
464 true/false condition values (most likely of use in conjunction with the
465 and{} expansion operator).
466
467 4. The $spam_score, $spam_bar and $spam_report variables are now available
468 at delivery time.
469
470 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
471 options, provided that Exim is invoked by an admin_user.
472
473 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
474 which increases compatibility with older clients at the cost of decreased
475 security. Don't set this unless you need to support such clients.
476
477 7. There is a new expansion operator, ${randint:...} which will produce a
478 "random" number less than the supplied integer. This randomness is
479 not guaranteed to be cryptographically strong, but depending upon how
480 Exim was built may be better than the most naive schemes.
481
482 8. Exim now explicitly ensures that SHA256 is available when linked against
483 OpenSSL.
484
485 9. The transport_filter_timeout option now applies to SMTP transports too.
486
487
488 Version 4.69
489 ------------
490
491 1. Preliminary DKIM support in Experimental.
492
493
494 Version 4.68
495 ------------
496
497 1. The body_linecount and body_zerocount C variables are now exported in the
498 local_scan API.
499
500 2. When a dnslists lookup succeeds, the key that was looked up is now placed
501 in $dnslist_matched. When the key is an IP address, it is not reversed in
502 this variable (though it is, of course, in the actual lookup). In simple
503 cases, for example:
504
505 deny dnslists = spamhaus.example
506
507 the key is also available in another variable (in this case,
508 $sender_host_address). In more complicated cases, however, this is not
509 true. For example, using a data lookup might generate a dnslists lookup
510 like this:
511
512 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
513
514 If this condition succeeds, the value in $dnslist_matched might be
515 192.168.6.7 (for example).
516
517 3. Authenticators now have a client_condition option. When Exim is running as
518 a client, it skips an authenticator whose client_condition expansion yields
519 "0", "no", or "false". This can be used, for example, to skip plain text
520 authenticators when the connection is not encrypted by a setting such as:
521
522 client_condition = ${if !eq{$tls_cipher}{}}
523
524 Note that the 4.67 documentation states that $tls_cipher contains the
525 cipher used for incoming messages. In fact, during SMTP delivery, it
526 contains the cipher used for the delivery. The same is true for
527 $tls_peerdn.
528
529 4. There is now a -Mvc <message-id> option, which outputs a copy of the
530 message to the standard output, in RFC 2822 format. The option can be used
531 only by an admin user.
532
533 5. There is now a /noupdate option for the ratelimit ACL condition. It
534 computes the rate and checks the limit as normal, but it does not update
535 the saved data. This means that, in relevant ACLs, it is possible to lookup
536 the existence of a specified (or auto-generated) ratelimit key without
537 incrementing the ratelimit counter for that key.
538
539 In order for this to be useful, another ACL entry must set the rate
540 for the same key somewhere (otherwise it will always be zero).
541
542 Example:
543
544 acl_check_connect:
545 # Read the rate; if it doesn't exist or is below the maximum
546 # we update it below
547 deny ratelimit = 100 / 5m / strict / noupdate
548 log_message = RATE: $sender_rate / $sender_rate_period \
549 (max $sender_rate_limit)
550
551 [... some other logic and tests...]
552
553 warn ratelimit = 100 / 5m / strict / per_cmd
554 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
555 (max $sender_rate_limit)
556 condition = ${if le{$sender_rate}{$sender_rate_limit}}
557
558 accept
559
560 6. The variable $max_received_linelength contains the number of bytes in the
561 longest line that was received as part of the message, not counting the
562 line termination character(s).
563
564 7. Host lists can now include +ignore_defer and +include_defer, analagous to
565 +ignore_unknown and +include_unknown. These options should be used with
566 care, probably only in non-critical host lists such as whitelists.
567
568 8. There's a new option called queue_only_load_latch, which defaults true.
569 If set false when queue_only_load is greater than zero, Exim re-evaluates
570 the load for each incoming message in an SMTP session. Otherwise, once one
571 message is queued, the remainder are also.
572
573 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
574 cases when an SMTP session ends without sending QUIT. However, when Exim
575 itself is is bad trouble, such as being unable to write to its log files,
576 this ACL is not run, because it might try to do things (such as write to
577 log files) that make the situation even worse.
578
579 Like the QUIT ACL, this new ACL is provided to make it possible to gather
580 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
581 modifier is forbidden in this ACL.
582
583 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
584 to a string that indicates the reason for the termination of the SMTP
585 connection. The possible values are:
586
587 acl-drop Another ACL issued a "drop" command
588 bad-commands Too many unknown or non-mail commands
589 command-timeout Timeout while reading SMTP commands
590 connection-lost The SMTP connection has been lost
591 data-timeout Timeout while reading message data
592 local-scan-error The local_scan() function crashed
593 local-scan-timeout The local_scan() function timed out
594 signal-exit SIGTERM or SIGINT
595 synchronization-error SMTP synchronization error
596 tls-failed TLS failed to start
597
598 In most cases when an SMTP connection is closed without having received
599 QUIT, Exim sends an SMTP response message before actually closing the
600 connection. With the exception of acl-drop, the default message can be
601 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
602 "drop" verb in another ACL, it is the message from the other ACL that is
603 used.
604
605 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
606 servers with individual queries. This is done by starting the query with
607 "servers=x:y:z;", where each item in the list may take one of two forms:
608
609 (1) If it is just a host name, the appropriate global option (mysql_servers
610 or pgsql_servers) is searched for a host of the same name, and the
611 remaining parameters (database, user, password) are taken from there.
612
613 (2) If it contains any slashes, it is taken as a complete parameter set.
614
615 The list of servers is used in exactly the same was as the global list.
616 Once a connection to a server has happened and a query has been
617 successfully executed, processing of the lookup ceases.
618
619 This feature is intended for use in master/slave situations where updates
620 are occurring, and one wants to update a master rather than a slave. If the
621 masters are in the list for reading, you might have:
622
623 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
624
625 In an updating lookup, you could then write
626
627 ${lookup mysql{servers=master; UPDATE ...}
628
629 If, on the other hand, the master is not to be used for reading lookups:
630
631 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
632
633 you can still update the master by
634
635 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
636
637 11. The message_body_newlines option (default FALSE, for backwards
638 compatibility) can be used to control whether newlines are present in
639 $message_body and $message_body_end. If it is FALSE, they are replaced by
640 spaces.
641
642
643 Version 4.67
644 ------------
645
646 1. There is a new log selector called smtp_no_mail, which is not included in
647 the default setting. When it is set, a line is written to the main log
648 whenever an accepted SMTP connection terminates without having issued a
649 MAIL command.
650
651 2. When an item in a dnslists list is followed by = and & and a list of IP
652 addresses, the behaviour was not clear when the lookup returned more than
653 one IP address. This has been solved by the addition of == and =& for "all"
654 rather than the default "any" matching.
655
656 3. Up till now, the only control over which cipher suites GnuTLS uses has been
657 for the cipher algorithms. New options have been added to allow some of the
658 other parameters to be varied.
659
660 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
661 set, Exim compiles a runtime option called disable_fsync.
662
663 5. There is a new variable called $smtp_count_at_connection_start.
664
665 6. There's a new control called no_pipelining.
666
667 7. There are two new variables called $sending_ip_address and $sending_port.
668 These are set whenever an SMTP connection to another host has been set up.
669
670 8. The expansion of the helo_data option in the smtp transport now happens
671 after the connection to the server has been made.
672
673 9. There is a new expansion operator ${rfc2047d: that decodes strings that
674 are encoded as per RFC 2047.
675
676 10. There is a new log selector called "pid", which causes the current process
677 id to be added to every log line, in square brackets, immediately after the
678 time and date.
679
680 11. Exim has been modified so that it flushes SMTP output before implementing
681 a delay in an ACL. It also flushes the output before performing a callout,
682 as this can take a substantial time. These behaviours can be disabled by
683 obeying control = no_delay_flush or control = no_callout_flush,
684 respectively, at some earlier stage of the connection.
685
686 12. There are two new expansion conditions that iterate over a list. They are
687 called forany and forall.
688
689 13. There's a new global option called dsn_from that can be used to vary the
690 contents of From: lines in bounces and other automatically generated
691 messages ("delivery status notifications" - hence the name of the option).
692
693 14. The smtp transport has a new option called hosts_avoid_pipelining.
694
695 15. By default, exigrep does case-insensitive matches. There is now a -I option
696 that makes it case-sensitive.
697
698 16. A number of new features ("addresses", "map", "filter", and "reduce") have
699 been added to string expansions to make it easier to process lists of
700 items, typically addresses.
701
702 17. There's a new ACL modifier called "continue". It does nothing of itself,
703 and processing of the ACL always continues with the next condition or
704 modifier. It is provided so that the side effects of expanding its argument
705 can be used.
706
707 18. It is now possible to use newline and other control characters (those with
708 values less than 32, plus DEL) as separators in lists.
709
710 19. The exigrep utility now has a -v option, which inverts the matching
711 condition.
712
713 20. The host_find_failed option in the manualroute router can now be set to
714 "ignore".
715
716
717 Version 4.66
718 ------------
719
720 No new features were added to 4.66.
721
722
723 Version 4.65
724 ------------
725
726 No new features were added to 4.65.
727
728
729 Version 4.64
730 ------------
731
732 1. ACL variables can now be given arbitrary names, as long as they start with
733 "acl_c" or "acl_m" (for connection variables and message variables), are at
734 least six characters long, with the sixth character being either a digit or
735 an underscore.
736
737 2. There is a new ACL modifier called log_reject_target. It makes it possible
738 to specify which logs are used for messages about ACL rejections.
739
740 3. There is a new authenticator called "dovecot". This is an interface to the
741 authentication facility of the Dovecot POP/IMAP server, which can support a
742 number of authentication methods.
743
744 4. The variable $message_headers_raw provides a concatenation of all the
745 messages's headers without any decoding. This is in contrast to
746 $message_headers, which does RFC2047 decoding on the header contents.
747
748 5. In a DNS black list, if two domain names, comma-separated, are given, the
749 second is used first to do an initial check, making use of any IP value
750 restrictions that are set. If there is a match, the first domain is used,
751 without any IP value restrictions, to get the TXT record.
752
753 6. All authenticators now have a server_condition option.
754
755 7. There is a new command-line option called -Mset. It is useful only in
756 conjunction with -be (that is, when testing string expansions). It must be
757 followed by a message id; Exim loads the given message from its spool
758 before doing the expansions.
759
760 8. Another similar new command-line option is called -bem. It operates like
761 -be except that it must be followed by the name of a file that contains a
762 message.
763
764 9. When an address is delayed because of a 4xx response to a RCPT command, it
765 is now the combination of sender and recipient that is delayed in
766 subsequent queue runs until its retry time is reached.
767
768 10. Unary negation and the bitwise logical operators and, or, xor, not, and
769 shift, have been added to the eval: and eval10: expansion items.
770
771 11. The variables $interface_address and $interface_port have been renamed
772 as $received_ip_address and $received_port, to make it clear that they
773 relate to message reception rather than delivery. (The old names remain
774 available for compatibility.)
775
776 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
777 to vary the message that is sent when an SMTP command is accepted.
778
779
780 Version 4.63
781 ------------
782
783 1. There is a new Boolean option called filter_prepend_home for the redirect
784 router.
785
786 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
787 start of receiving a non-SMTP message, before any of the message has been
788 read.
789
790 3. When an SMTP error message is specified in a "message" modifier in an ACL,
791 or in a :fail: or :defer: message in a redirect router, Exim now checks the
792 start of the message for an SMTP error code.
793
794 4. There is a new parameter for LDAP lookups called "referrals", which takes
795 one of the settings "follow" (the default) or "nofollow".
796
797 5. Version 20070721.2 of exipick now included, offering these new options:
798 --reverse
799 After all other sorting options have bee processed, reverse order
800 before displaying messages (-R is synonym).
801 --random
802 Randomize order of matching messages before displaying.
803 --size
804 Instead of displaying the matching messages, display the sum
805 of their sizes.
806 --sort <variable>[,<variable>...]
807 Before displaying matching messages, sort the messages according to
808 each messages value for each variable.
809 --not
810 Negate the value for every test (returns inverse output from the
811 same criteria without --not).
812
813
814 Version 4.62
815 ------------
816
817 1. The ${readsocket expansion item now supports Internet domain sockets as well
818 as Unix domain sockets. If the first argument begins "inet:", it must be of
819 the form "inet:host:port". The port is mandatory; it may be a number or the
820 name of a TCP port in /etc/services. The host may be a name, or it may be an
821 IP address. An ip address may optionally be enclosed in square brackets.
822 This is best for IPv6 addresses. For example:
823
824 ${readsocket{inet:[::1]:1234}{<request data>}...
825
826 Only a single host name may be given, but if looking it up yield more than
827 one IP address, they are each tried in turn until a connection is made. Once
828 a connection has been made, the behaviour is as for ${readsocket with a Unix
829 domain socket.
830
831 2. If a redirect router sets up file or pipe deliveries for more than one
832 incoming address, and the relevant transport has batch_max set greater than
833 one, a batch delivery now occurs.
834
835 3. The appendfile transport has a new option called maildirfolder_create_regex.
836 Its value is a regular expression. For a maildir delivery, this is matched
837 against the maildir directory; if it matches, Exim ensures that a
838 maildirfolder file is created alongside the new, cur, and tmp directories.
839
840
841 Version 4.61
842 ------------
843
844 The documentation is up-to-date for the 4.61 release. Major new features since
845 the 4.60 release are:
846
847 . An option called disable_ipv6, to disable the use of IPv6 completely.
848
849 . An increase in the number of ACL variables to 20 of each type.
850
851 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
852 $2, $3, (though those are still set) because the numeric variables get used
853 for other things in complicated expansions.
854
855 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
856
857 . It is possible to use setclassresources() on some BSD OS to control the
858 resources used in pipe deliveries.
859
860 . A new ACL modifier called add_header, which can be used with any verb.
861
862 . More errors are detectable in retry rules.
863
864 There are a number of other additions too.
865
866
867 Version 4.60
868 ------------
869
870 The documentation is up-to-date for the 4.60 release. Major new features since
871 the 4.50 release are:
872
873 . Support for SQLite.
874
875 . Support for IGNOREQUOTA in LMTP.
876
877 . Extensions to the "submission mode" features.
878
879 . Support for Client SMTP Authorization (CSA).
880
881 . Support for ratelimiting hosts and users.
882
883 . New expansion items to help with the BATV "prvs" scheme.
884
885 . A "match_ip" condition, that matches an IP address against a list.
886
887 There are many more minor changes.
888
889 ****