Bug #198: Add remove_header ACL modifier.
[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 4.81
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_use_dnssec; 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.
39
40 Current status: work-in-progress; $sender_host_dnssec variable added.
41
42 5. DSCP support for outbound connections: on a transport using the smtp driver,
43 set "dscp = ef", for instance, to cause the connections to have the relevant
44 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
45
46 Similarly for inbound connections, there is a new control modifier, dscp,
47 so "warn control = dscp/ef" in the connect ACL, or after authentication.
48
49 Supported values depend upon system libraries. "exim -bI:dscp" to list the
50 ones Exim knows of. You can also set a raw number 0..0x3F.
51
52 6. The -G command-line flag is no longer ignored; it is now equivalent to an
53 ACL setting "control = suppress_local_fixups". The -L command-line flag
54 is now accepted and forces use of syslog, with the provided tag as the
55 process name. A few other flags used by Sendmail are now accepted and
56 ignored.
57
58 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
59 ACL modifier; works for single-recipient mails which are recieved on and
60 deliverable via SMTP. Using the connection made for a recipient verify,
61 if requested before the verify, or a new one made for the purpose while
62 the inbound connection is still active. The bulk of the mail item is copied
63 direct from the inbound socket to the outbound (as well as the spool file).
64 When the source notifies the end of data, the data acceptance by the destination
65 is negociated before the acceptance is sent to the source. If the destination
66 does not accept the mail item, for example due to content-scanning, the item
67 is not accepted from the source and therefore there is no need to generate
68 a bounce mail. This is of benefit when providing a secondary-MX service.
69 The downside is that delays are under the control of the ultimate destination
70 system not your own.
71
72 The Recieved-by: header on items delivered by cutthrough is generated
73 early in reception rather than at the end; this will affect any timestamp
74 included. The log line showing delivery is recorded before that showing
75 reception; it uses a new ">>" tag instead of "=>".
76
77 To support the feature, verify-callout connections can now use ESMTP and TLS.
78 The usual smtp transport options are honoured, plus a (new, default everything)
79 hosts_verify_avoid_tls.
80
81 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
82 for specific access to the information for each connection. The old names
83 are present for now but deprecated.
84
85 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING, AUTH.
86
87 8. New expansion operators ${listnamed:name} to get the content of a named list
88 and ${listcount:string} to count the items in a list.
89
90 9. New global option "gnutls_enable_pkcs11", defaults false. The GnuTLS
91 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
92 modules. For some situations this is desirable, but we expect admin in
93 those situations to know they want the feature. More commonly, it means
94 that GUI user modules get loaded and are broken by the setuid Exim being
95 unable to access files specified in environment variables and passed
96 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
97 unless this new option is set.
98
99 10. The "acl = name" condition on an ACL now supports optional arguments.
100 New expansion item "${acl {name}{arg}...}" and expansion condition
101 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
102 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
103 Variable $acl_narg contains the number of arguments. If the ACL sets
104 a "message =" value this becomes the result of the expansion item,
105 or the value of $value for the expansion condition. If the ACL returns
106 accept the expansion condition is true; if reject, false. A defer
107 return results in a forced fail.
108
109 11. Routers and transports can now have multiple headers_add and headers_remove
110 option lines. The concatenated list is used.
111
112 12. New ACL modifier "remove_header" can remove headers before message gets
113 handled by routers/transports.
114
115 Version 4.80
116 ------------
117
118 1. New authenticator driver, "gsasl". Server-only (at present).
119 This is a SASL interface, licensed under GPL, which can be found at
120 http://www.gnu.org/software/gsasl/.
121 This system does not provide sources of data for authentication, so
122 careful use needs to be made of the conditions in Exim.
123
124 2. New authenticator driver, "heimdal_gssapi". Server-only.
125 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
126 is no longer honoured for setuid programs by Heimdal. Use the
127 "server_keytab" option to point to the keytab.
128
129 3. The "pkg-config" system can now be used when building Exim to reference
130 cflags and library information for lookups and authenticators, rather
131 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
132 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
133 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
134
135 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
136 find the headers and libraries for PCRE.
137
138 4. New expansion variable $tls_bits.
139
140 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
141 be joined together with ASCII NUL characters to construct the key to pass
142 into the DBM library. Can be used with gsasl to access sasldb2 files as
143 used by Cyrus SASL.
144
145 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
146
147 Avoid release 1.0.1a if you can. Note that the default value of
148 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
149 increased susceptibility to attack. This may still have interoperability
150 implications for very old clients (see version 4.31 change 37) but
151 administrators can choose to make the trade-off themselves and restore
152 compatibility at the cost of session security.
153
154 7. Use of the new expansion variable $tls_sni in the main configuration option
155 tls_certificate will cause Exim to re-expand the option, if the client
156 sends the TLS Server Name Indication extension, to permit choosing a
157 different certificate; tls_privatekey will also be re-expanded. You must
158 still set these options to expand to valid files when $tls_sni is not set.
159
160 The SMTP Transport has gained the option tls_sni, which will set a hostname
161 for outbound TLS sessions, and set $tls_sni too.
162
163 A new log_selector, +tls_sni, has been added, to log received SNI values
164 for Exim as a server.
165
166 8. The existing "accept_8bitmime" option now defaults to true. This means
167 that Exim is deliberately not strictly RFC compliant. We're following
168 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
169 Those who disagree, or know that they are talking to mail servers that,
170 even today, are not 8-bit clean, need to turn off this option.
171
172 9. Exim can now be started with -bw (with an optional timeout, given as
173 -bw<timespec>). With this, stdin at startup is a socket that is
174 already listening for connections. This has a more modern name of
175 "socket activation", but forcing the activated socket to fd 0. We're
176 interested in adding more support for modern variants.
177
178 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
179 for numbers indicates multiplication by 1024^3.
180
181 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
182 gnutls_require_mac & gnutls_require_protocols are no longer supported.
183 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
184 string, documentation for which is at:
185 http://www.gnu.org/software/gnutls/manual/html_node/Priority-Strings.html
186
187 SNI support has been added to Exim's GnuTLS integration too.
188
189 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
190 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
191
192 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
193 is now available. If the contents of the file are valid, then Exim will
194 send that back in response to a TLS status request; this is OCSP Stapling.
195 Exim will not maintain the contents of the file in any way: administrators
196 are responsible for ensuring that it is up-to-date.
197
198 See "experimental-spec.txt" for more details.
199
200 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
201 identically to TXT record lookups.
202
203 14. New expansion variable $tod_epoch_l for higher-precision time.
204
205 15. New global option tls_dh_max_bits, defaulting to current value of NSS
206 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
207 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
208
209 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
210 Option can now be a path or an identifier for a standard prime.
211 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
212 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
213 primes.
214
215 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
216 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
217 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
218
219
220 Version 4.77
221 ------------
222
223 1. New options for the ratelimit ACL condition: /count= and /unique=.
224 The /noupdate option has been replaced by a /readonly option.
225
226 2. The SMTP transport's protocol option may now be set to "smtps", to
227 use SSL-on-connect outbound.
228
229 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
230 there is a problem talking to the AV scanner, or the AV scanner running.
231
232 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
233 and check if the search item is a member of the list. This does not
234 support named lists, but does subject the list part to string expansion.
235
236 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
237 built, Exim no longer performs string expansion on the second string of
238 the match_* expansion conditions: "match_address", "match_domain",
239 "match_ip" & "match_local_part". Named lists can still be used.
240
241
242 Version 4.76
243 ------------
244
245 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
246 or off in the resolver library.
247
248
249 Version 4.75
250 ------------
251
252 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
253 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
254 libraries. The following global options have been added in support of
255 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
256 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
257
258 2. The pipe transport now takes a boolean option, "freeze_signal", default
259 false. When true, if the external delivery command exits on a signal then
260 Exim will freeze the message in the queue, instead of generating a bounce.
261
262 3. Log filenames may now use %M as an escape, instead of %D (still available).
263 The %M pattern expands to yyyymm, providing month-level resolution.
264
265 4. The $message_linecount variable is now updated for the maildir_tag option,
266 in the same way as $message_size, to reflect the real number of lines,
267 including any header additions or removals from transport.
268
269 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
270 Exim now selects entries randomly, to better scale in a cluster setup.
271
272
273 Version 4.74
274 ------------
275
276 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
277 the flaw permitted the Exim run-time user to cause root to append to
278 arbitrary files of the attacker's choosing, with the content based
279 on content supplied by the attacker.
280
281 2. Exim now supports loading some lookup types at run-time, using your
282 platform's dlopen() functionality. This has limited platform support
283 and the intention is not to support every variant, it's limited to
284 dlopen(). This permits the main Exim binary to not be linked against
285 all the libraries needed for all the lookup types.
286
287
288 Version 4.73
289 ------------
290
291 NOTE: this version is not guaranteed backwards-compatible, please read the
292 items below carefully
293
294 1. A new main configuration option, "openssl_options", is available if Exim
295 is built with SSL support provided by OpenSSL. The option allows
296 administrators to specify OpenSSL options to be used on connections;
297 typically this is to set bug compatibility features which the OpenSSL
298 developers have not enabled by default. There may be security
299 consequences for certain options, so these should not be changed
300 frivolously.
301
302 2. A new pipe transport option, "permit_coredumps", may help with problem
303 diagnosis in some scenarios. Note that Exim is typically installed as
304 a setuid binary, which on most OSes will inhibit coredumps by default,
305 so that safety mechanism would have to be overridden for this option to
306 be able to take effect.
307
308 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
309 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
310 Note that this switches Exim to use a new API ("INSTREAM") and a future
311 release of ClamAV will remove support for the old API ("STREAM").
312
313 The av_scanner option, when set to "clamd", now takes an optional third
314 part, "local", which causes Exim to pass a filename to ClamAV instead of
315 the file content. This is the same behaviour as when clamd is pointed at
316 a Unix-domain socket. For example:
317
318 av_scanner = clamd:192.0.2.3 1234:local
319
320 ClamAV's ExtendedDetectionInfo response format is now handled.
321
322 4. There is now a -bmalware option, restricted to admin users. This option
323 takes one parameter, a filename, and scans that file with Exim's
324 malware-scanning framework. This is intended purely as a debugging aid
325 to ensure that Exim's scanning is working, not to replace other tools.
326 Note that the ACL framework is not invoked, so if av_scanner references
327 ACL variables without a fallback then this will fail.
328
329 5. There is a new expansion operator, "reverse_ip", which will reverse IP
330 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
331
332 ${reverse_ip:192.0.2.4}
333 -> 4.2.0.192
334 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
335 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
336
337 6. There is a new ACL control called "debug", to enable debug logging.
338 This allows selective logging of certain incoming transactions within
339 production environments, with some care. It takes two options, "tag"
340 and "opts"; "tag" is included in the filename of the log and "opts"
341 is used as per the -d<options> command-line option. Examples, which
342 don't all make sense in all contexts:
343
344 control = debug
345 control = debug/tag=.$sender_host_address
346 control = debug/opts=+expand+acl
347 control = debug/tag=.$message_exim_id/opts=+expand
348
349 7. It has always been implicit in the design and the documentation that
350 "the Exim user" is not root. src/EDITME said that using root was
351 "very strongly discouraged". This is not enough to keep people from
352 shooting themselves in the foot in days when many don't configure Exim
353 themselves but via package build managers. The security consequences of
354 running various bits of network code are severe if there should be bugs in
355 them. As such, the Exim user may no longer be root. If configured
356 statically, Exim will refuse to build. If configured as ref:user then Exim
357 will exit shortly after start-up. If you must shoot yourself in the foot,
358 then henceforth you will have to maintain your own local patches to strip
359 the safeties off.
360
361 8. There is a new expansion operator, bool_lax{}. Where bool{} uses the ACL
362 condition logic to determine truth/failure and will fail to expand many
363 strings, bool_lax{} uses the router condition logic, where most strings
364 do evaluate true.
365 Note: bool{00} is false, bool_lax{00} is true.
366
367 9. Routers now support multiple "condition" tests,
368
369 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
370 Setting this allows an admin to define which entry in the tcpwrappers
371 config file will be used to control access to the daemon. This option
372 is only available when Exim is built with USE_TCP_WRAPPERS. The
373 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
374 build option.
375
376 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
377 the Exim run-time user, instead of root.
378
379 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
380 is forced on. This is mitigated by the new build option
381 TRUSTED_CONFIG_LIST which defines a list of configuration files which
382 are trusted; one per line. If a config file is owned by root and matches
383 a pathname in the list, then it may be invoked by the Exim build-time
384 user without Exim relinquishing root privileges.
385
386 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
387 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
388 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
389 include the main config. As a transition mechanism, we are temporarily
390 providing a work-around: the new build option WHITELIST_D_MACROS provides
391 a colon-separated list of macro names which may be overridden by the Exim
392 run-time user. The values of these macros are constrained to the regex
393 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
394
395
396 Version 4.72
397 ------------
398
399 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
400 writable, the other to locking of MBX folders (not mbox).
401
402 2. MySQL stored procedures are now supported.
403
404 3. The dkim_domain transport option is now a list, not a single string, and
405 messages will be signed for each element in the list (discarding
406 duplicates).
407
408 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
409 in the presence of multiple character strings within the RR. Prior to 4.70,
410 only the first string would be returned. The dnsdb lookup now, by default,
411 preserves the pre-4.70 semantics, but also now takes an extended output
412 separator specification. The separator can be followed by a semicolon, to
413 concatenate the individual text strings together with no join character,
414 or by a comma and a second separator character, in which case the text
415 strings within a TXT record are joined on that second character.
416 Administrators are reminded that DNS provides no ordering guarantees
417 between multiple records in an RRset. For example:
418
419 foo.example. IN TXT "a" "b" "c"
420 foo.example. IN TXT "d" "e" "f"
421
422 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
423 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
424 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
425
426
427 Version 4.70 / 4.71
428 -------------------
429
430 1. Native DKIM support without an external library.
431 (Note that if no action to prevent it is taken, a straight upgrade will
432 result in DKIM verification of all signed incoming emails. See spec
433 for details on conditionally disabling)
434
435 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
436
437 3. There is now a bool{} expansion condition which maps certain strings to
438 true/false condition values (most likely of use in conjunction with the
439 and{} expansion operator).
440
441 4. The $spam_score, $spam_bar and $spam_report variables are now available
442 at delivery time.
443
444 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
445 options, provided that Exim is invoked by an admin_user.
446
447 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
448 which increases compatibility with older clients at the cost of decreased
449 security. Don't set this unless you need to support such clients.
450
451 7. There is a new expansion operator, ${randint:...} which will produce a
452 "random" number less than the supplied integer. This randomness is
453 not guaranteed to be cryptographically strong, but depending upon how
454 Exim was built may be better than the most naive schemes.
455
456 8. Exim now explicitly ensures that SHA256 is available when linked against
457 OpenSSL.
458
459 9. The transport_filter_timeout option now applies to SMTP transports too.
460
461
462 Version 4.69
463 ------------
464
465 1. Preliminary DKIM support in Experimental.
466
467
468 Version 4.68
469 ------------
470
471 1. The body_linecount and body_zerocount C variables are now exported in the
472 local_scan API.
473
474 2. When a dnslists lookup succeeds, the key that was looked up is now placed
475 in $dnslist_matched. When the key is an IP address, it is not reversed in
476 this variable (though it is, of course, in the actual lookup). In simple
477 cases, for example:
478
479 deny dnslists = spamhaus.example
480
481 the key is also available in another variable (in this case,
482 $sender_host_address). In more complicated cases, however, this is not
483 true. For example, using a data lookup might generate a dnslists lookup
484 like this:
485
486 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
487
488 If this condition succeeds, the value in $dnslist_matched might be
489 192.168.6.7 (for example).
490
491 3. Authenticators now have a client_condition option. When Exim is running as
492 a client, it skips an authenticator whose client_condition expansion yields
493 "0", "no", or "false". This can be used, for example, to skip plain text
494 authenticators when the connection is not encrypted by a setting such as:
495
496 client_condition = ${if !eq{$tls_cipher}{}}
497
498 Note that the 4.67 documentation states that $tls_cipher contains the
499 cipher used for incoming messages. In fact, during SMTP delivery, it
500 contains the cipher used for the delivery. The same is true for
501 $tls_peerdn.
502
503 4. There is now a -Mvc <message-id> option, which outputs a copy of the
504 message to the standard output, in RFC 2822 format. The option can be used
505 only by an admin user.
506
507 5. There is now a /noupdate option for the ratelimit ACL condition. It
508 computes the rate and checks the limit as normal, but it does not update
509 the saved data. This means that, in relevant ACLs, it is possible to lookup
510 the existence of a specified (or auto-generated) ratelimit key without
511 incrementing the ratelimit counter for that key.
512
513 In order for this to be useful, another ACL entry must set the rate
514 for the same key somewhere (otherwise it will always be zero).
515
516 Example:
517
518 acl_check_connect:
519 # Read the rate; if it doesn't exist or is below the maximum
520 # we update it below
521 deny ratelimit = 100 / 5m / strict / noupdate
522 log_message = RATE: $sender_rate / $sender_rate_period \
523 (max $sender_rate_limit)
524
525 [... some other logic and tests...]
526
527 warn ratelimit = 100 / 5m / strict / per_cmd
528 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
529 (max $sender_rate_limit)
530 condition = ${if le{$sender_rate}{$sender_rate_limit}}
531
532 accept
533
534 6. The variable $max_received_linelength contains the number of bytes in the
535 longest line that was received as part of the message, not counting the
536 line termination character(s).
537
538 7. Host lists can now include +ignore_defer and +include_defer, analagous to
539 +ignore_unknown and +include_unknown. These options should be used with
540 care, probably only in non-critical host lists such as whitelists.
541
542 8. There's a new option called queue_only_load_latch, which defaults true.
543 If set false when queue_only_load is greater than zero, Exim re-evaluates
544 the load for each incoming message in an SMTP session. Otherwise, once one
545 message is queued, the remainder are also.
546
547 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
548 cases when an SMTP session ends without sending QUIT. However, when Exim
549 itself is is bad trouble, such as being unable to write to its log files,
550 this ACL is not run, because it might try to do things (such as write to
551 log files) that make the situation even worse.
552
553 Like the QUIT ACL, this new ACL is provided to make it possible to gather
554 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
555 modifier is forbidden in this ACL.
556
557 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
558 to a string that indicates the reason for the termination of the SMTP
559 connection. The possible values are:
560
561 acl-drop Another ACL issued a "drop" command
562 bad-commands Too many unknown or non-mail commands
563 command-timeout Timeout while reading SMTP commands
564 connection-lost The SMTP connection has been lost
565 data-timeout Timeout while reading message data
566 local-scan-error The local_scan() function crashed
567 local-scan-timeout The local_scan() function timed out
568 signal-exit SIGTERM or SIGINT
569 synchronization-error SMTP synchronization error
570 tls-failed TLS failed to start
571
572 In most cases when an SMTP connection is closed without having received
573 QUIT, Exim sends an SMTP response message before actually closing the
574 connection. With the exception of acl-drop, the default message can be
575 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
576 "drop" verb in another ACL, it is the message from the other ACL that is
577 used.
578
579 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
580 servers with individual queries. This is done by starting the query with
581 "servers=x:y:z;", where each item in the list may take one of two forms:
582
583 (1) If it is just a host name, the appropriate global option (mysql_servers
584 or pgsql_servers) is searched for a host of the same name, and the
585 remaining parameters (database, user, password) are taken from there.
586
587 (2) If it contains any slashes, it is taken as a complete parameter set.
588
589 The list of servers is used in exactly the same was as the global list.
590 Once a connection to a server has happened and a query has been
591 successfully executed, processing of the lookup ceases.
592
593 This feature is intended for use in master/slave situations where updates
594 are occurring, and one wants to update a master rather than a slave. If the
595 masters are in the list for reading, you might have:
596
597 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
598
599 In an updating lookup, you could then write
600
601 ${lookup mysql{servers=master; UPDATE ...}
602
603 If, on the other hand, the master is not to be used for reading lookups:
604
605 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
606
607 you can still update the master by
608
609 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
610
611 11. The message_body_newlines option (default FALSE, for backwards
612 compatibility) can be used to control whether newlines are present in
613 $message_body and $message_body_end. If it is FALSE, they are replaced by
614 spaces.
615
616
617 Version 4.67
618 ------------
619
620 1. There is a new log selector called smtp_no_mail, which is not included in
621 the default setting. When it is set, a line is written to the main log
622 whenever an accepted SMTP connection terminates without having issued a
623 MAIL command.
624
625 2. When an item in a dnslists list is followed by = and & and a list of IP
626 addresses, the behaviour was not clear when the lookup returned more than
627 one IP address. This has been solved by the addition of == and =& for "all"
628 rather than the default "any" matching.
629
630 3. Up till now, the only control over which cipher suites GnuTLS uses has been
631 for the cipher algorithms. New options have been added to allow some of the
632 other parameters to be varied.
633
634 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
635 set, Exim compiles a runtime option called disable_fsync.
636
637 5. There is a new variable called $smtp_count_at_connection_start.
638
639 6. There's a new control called no_pipelining.
640
641 7. There are two new variables called $sending_ip_address and $sending_port.
642 These are set whenever an SMTP connection to another host has been set up.
643
644 8. The expansion of the helo_data option in the smtp transport now happens
645 after the connection to the server has been made.
646
647 9. There is a new expansion operator ${rfc2047d: that decodes strings that
648 are encoded as per RFC 2047.
649
650 10. There is a new log selector called "pid", which causes the current process
651 id to be added to every log line, in square brackets, immediately after the
652 time and date.
653
654 11. Exim has been modified so that it flushes SMTP output before implementing
655 a delay in an ACL. It also flushes the output before performing a callout,
656 as this can take a substantial time. These behaviours can be disabled by
657 obeying control = no_delay_flush or control = no_callout_flush,
658 respectively, at some earlier stage of the connection.
659
660 12. There are two new expansion conditions that iterate over a list. They are
661 called forany and forall.
662
663 13. There's a new global option called dsn_from that can be used to vary the
664 contents of From: lines in bounces and other automatically generated
665 messages ("delivery status notifications" - hence the name of the option).
666
667 14. The smtp transport has a new option called hosts_avoid_pipelining.
668
669 15. By default, exigrep does case-insensitive matches. There is now a -I option
670 that makes it case-sensitive.
671
672 16. A number of new features ("addresses", "map", "filter", and "reduce") have
673 been added to string expansions to make it easier to process lists of
674 items, typically addresses.
675
676 17. There's a new ACL modifier called "continue". It does nothing of itself,
677 and processing of the ACL always continues with the next condition or
678 modifier. It is provided so that the side effects of expanding its argument
679 can be used.
680
681 18. It is now possible to use newline and other control characters (those with
682 values less than 32, plus DEL) as separators in lists.
683
684 19. The exigrep utility now has a -v option, which inverts the matching
685 condition.
686
687 20. The host_find_failed option in the manualroute router can now be set to
688 "ignore".
689
690
691 Version 4.66
692 ------------
693
694 No new features were added to 4.66.
695
696
697 Version 4.65
698 ------------
699
700 No new features were added to 4.65.
701
702
703 Version 4.64
704 ------------
705
706 1. ACL variables can now be given arbitrary names, as long as they start with
707 "acl_c" or "acl_m" (for connection variables and message variables), are at
708 least six characters long, with the sixth character being either a digit or
709 an underscore.
710
711 2. There is a new ACL modifier called log_reject_target. It makes it possible
712 to specify which logs are used for messages about ACL rejections.
713
714 3. There is a new authenticator called "dovecot". This is an interface to the
715 authentication facility of the Dovecot POP/IMAP server, which can support a
716 number of authentication methods.
717
718 4. The variable $message_headers_raw provides a concatenation of all the
719 messages's headers without any decoding. This is in contrast to
720 $message_headers, which does RFC2047 decoding on the header contents.
721
722 5. In a DNS black list, if two domain names, comma-separated, are given, the
723 second is used first to do an initial check, making use of any IP value
724 restrictions that are set. If there is a match, the first domain is used,
725 without any IP value restrictions, to get the TXT record.
726
727 6. All authenticators now have a server_condition option.
728
729 7. There is a new command-line option called -Mset. It is useful only in
730 conjunction with -be (that is, when testing string expansions). It must be
731 followed by a message id; Exim loads the given message from its spool
732 before doing the expansions.
733
734 8. Another similar new command-line option is called -bem. It operates like
735 -be except that it must be followed by the name of a file that contains a
736 message.
737
738 9. When an address is delayed because of a 4xx response to a RCPT command, it
739 is now the combination of sender and recipient that is delayed in
740 subsequent queue runs until its retry time is reached.
741
742 10. Unary negation and the bitwise logical operators and, or, xor, not, and
743 shift, have been added to the eval: and eval10: expansion items.
744
745 11. The variables $interface_address and $interface_port have been renamed
746 as $received_ip_address and $received_port, to make it clear that they
747 relate to message reception rather than delivery. (The old names remain
748 available for compatibility.)
749
750 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
751 to vary the message that is sent when an SMTP command is accepted.
752
753
754 Version 4.63
755 ------------
756
757 1. There is a new Boolean option called filter_prepend_home for the redirect
758 router.
759
760 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
761 start of receiving a non-SMTP message, before any of the message has been
762 read.
763
764 3. When an SMTP error message is specified in a "message" modifier in an ACL,
765 or in a :fail: or :defer: message in a redirect router, Exim now checks the
766 start of the message for an SMTP error code.
767
768 4. There is a new parameter for LDAP lookups called "referrals", which takes
769 one of the settings "follow" (the default) or "nofollow".
770
771 5. Version 20070721.2 of exipick now included, offering these new options:
772 --reverse
773 After all other sorting options have bee processed, reverse order
774 before displaying messages (-R is synonym).
775 --random
776 Randomize order of matching messages before displaying.
777 --size
778 Instead of displaying the matching messages, display the sum
779 of their sizes.
780 --sort <variable>[,<variable>...]
781 Before displaying matching messages, sort the messages according to
782 each messages value for each variable.
783 --not
784 Negate the value for every test (returns inverse output from the
785 same criteria without --not).
786
787
788 Version 4.62
789 ------------
790
791 1. The ${readsocket expansion item now supports Internet domain sockets as well
792 as Unix domain sockets. If the first argument begins "inet:", it must be of
793 the form "inet:host:port". The port is mandatory; it may be a number or the
794 name of a TCP port in /etc/services. The host may be a name, or it may be an
795 IP address. An ip address may optionally be enclosed in square brackets.
796 This is best for IPv6 addresses. For example:
797
798 ${readsocket{inet:[::1]:1234}{<request data>}...
799
800 Only a single host name may be given, but if looking it up yield more than
801 one IP address, they are each tried in turn until a connection is made. Once
802 a connection has been made, the behaviour is as for ${readsocket with a Unix
803 domain socket.
804
805 2. If a redirect router sets up file or pipe deliveries for more than one
806 incoming address, and the relevant transport has batch_max set greater than
807 one, a batch delivery now occurs.
808
809 3. The appendfile transport has a new option called maildirfolder_create_regex.
810 Its value is a regular expression. For a maildir delivery, this is matched
811 against the maildir directory; if it matches, Exim ensures that a
812 maildirfolder file is created alongside the new, cur, and tmp directories.
813
814
815 Version 4.61
816 ------------
817
818 The documentation is up-to-date for the 4.61 release. Major new features since
819 the 4.60 release are:
820
821 . An option called disable_ipv6, to disable the use of IPv6 completely.
822
823 . An increase in the number of ACL variables to 20 of each type.
824
825 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
826 $2, $3, (though those are still set) because the numeric variables get used
827 for other things in complicated expansions.
828
829 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
830
831 . It is possible to use setclassresources() on some BSD OS to control the
832 resources used in pipe deliveries.
833
834 . A new ACL modifier called add_header, which can be used with any verb.
835
836 . More errors are detectable in retry rules.
837
838 There are a number of other additions too.
839
840
841 Version 4.60
842 ------------
843
844 The documentation is up-to-date for the 4.60 release. Major new features since
845 the 4.50 release are:
846
847 . Support for SQLite.
848
849 . Support for IGNOREQUOTA in LMTP.
850
851 . Extensions to the "submission mode" features.
852
853 . Support for Client SMTP Authorization (CSA).
854
855 . Support for ratelimiting hosts and users.
856
857 . New expansion items to help with the BATV "prvs" scheme.
858
859 . A "match_ip" condition, that matches an IP address against a list.
860
861 There are many more minor changes.
862
863 ****