Additions to the NewStuff summary file
[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 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
141 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
142 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
143 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
144 dmarc_status. It adds new control flags dmarc_disable_verify and
145 dmarc_enable_forensic.
146
147 22. Add expansion variable $authenticated_fail_id, which is the username
148 provided to the authentication method which failed. It is available
149 for use in subsequent ACL processing (typically quit or notquit ACLs).
150
151
152 Version 4.80
153 ------------
154
155 1. New authenticator driver, "gsasl". Server-only (at present).
156 This is a SASL interface, licensed under GPL, which can be found at
157 http://www.gnu.org/software/gsasl/.
158 This system does not provide sources of data for authentication, so
159 careful use needs to be made of the conditions in Exim.
160
161 2. New authenticator driver, "heimdal_gssapi". Server-only.
162 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
163 is no longer honoured for setuid programs by Heimdal. Use the
164 "server_keytab" option to point to the keytab.
165
166 3. The "pkg-config" system can now be used when building Exim to reference
167 cflags and library information for lookups and authenticators, rather
168 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
169 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
170 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
171
172 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
173 find the headers and libraries for PCRE.
174
175 4. New expansion variable $tls_bits.
176
177 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
178 be joined together with ASCII NUL characters to construct the key to pass
179 into the DBM library. Can be used with gsasl to access sasldb2 files as
180 used by Cyrus SASL.
181
182 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
183
184 Avoid release 1.0.1a if you can. Note that the default value of
185 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
186 increased susceptibility to attack. This may still have interoperability
187 implications for very old clients (see version 4.31 change 37) but
188 administrators can choose to make the trade-off themselves and restore
189 compatibility at the cost of session security.
190
191 7. Use of the new expansion variable $tls_sni in the main configuration option
192 tls_certificate will cause Exim to re-expand the option, if the client
193 sends the TLS Server Name Indication extension, to permit choosing a
194 different certificate; tls_privatekey will also be re-expanded. You must
195 still set these options to expand to valid files when $tls_sni is not set.
196
197 The SMTP Transport has gained the option tls_sni, which will set a hostname
198 for outbound TLS sessions, and set $tls_sni too.
199
200 A new log_selector, +tls_sni, has been added, to log received SNI values
201 for Exim as a server.
202
203 8. The existing "accept_8bitmime" option now defaults to true. This means
204 that Exim is deliberately not strictly RFC compliant. We're following
205 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
206 Those who disagree, or know that they are talking to mail servers that,
207 even today, are not 8-bit clean, need to turn off this option.
208
209 9. Exim can now be started with -bw (with an optional timeout, given as
210 -bw<timespec>). With this, stdin at startup is a socket that is
211 already listening for connections. This has a more modern name of
212 "socket activation", but forcing the activated socket to fd 0. We're
213 interested in adding more support for modern variants.
214
215 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
216 for numbers indicates multiplication by 1024^3.
217
218 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
219 gnutls_require_mac & gnutls_require_protocols are no longer supported.
220 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
221 string, documentation for which is at:
222 http://www.gnutls.org/manual/html_node/Priority-Strings.html
223
224 SNI support has been added to Exim's GnuTLS integration too.
225
226 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
227 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
228
229 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
230 is now available. If the contents of the file are valid, then Exim will
231 send that back in response to a TLS status request; this is OCSP Stapling.
232 Exim will not maintain the contents of the file in any way: administrators
233 are responsible for ensuring that it is up-to-date.
234
235 See "experimental-spec.txt" for more details.
236
237 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
238 identically to TXT record lookups.
239
240 14. New expansion variable $tod_epoch_l for higher-precision time.
241
242 15. New global option tls_dh_max_bits, defaulting to current value of NSS
243 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
244 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
245
246 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
247 Option can now be a path or an identifier for a standard prime.
248 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
249 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
250 primes.
251
252 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
253 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
254 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
255
256
257 Version 4.77
258 ------------
259
260 1. New options for the ratelimit ACL condition: /count= and /unique=.
261 The /noupdate option has been replaced by a /readonly option.
262
263 2. The SMTP transport's protocol option may now be set to "smtps", to
264 use SSL-on-connect outbound.
265
266 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
267 there is a problem talking to the AV scanner, or the AV scanner running.
268
269 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
270 and check if the search item is a member of the list. This does not
271 support named lists, but does subject the list part to string expansion.
272
273 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
274 built, Exim no longer performs string expansion on the second string of
275 the match_* expansion conditions: "match_address", "match_domain",
276 "match_ip" & "match_local_part". Named lists can still be used.
277
278
279 Version 4.76
280 ------------
281
282 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
283 or off in the resolver library.
284
285
286 Version 4.75
287 ------------
288
289 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
290 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
291 libraries. The following global options have been added in support of
292 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
293 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
294
295 2. The pipe transport now takes a boolean option, "freeze_signal", default
296 false. When true, if the external delivery command exits on a signal then
297 Exim will freeze the message in the queue, instead of generating a bounce.
298
299 3. Log filenames may now use %M as an escape, instead of %D (still available).
300 The %M pattern expands to yyyymm, providing month-level resolution.
301
302 4. The $message_linecount variable is now updated for the maildir_tag option,
303 in the same way as $message_size, to reflect the real number of lines,
304 including any header additions or removals from transport.
305
306 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
307 Exim now selects entries randomly, to better scale in a cluster setup.
308
309
310 Version 4.74
311 ------------
312
313 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
314 the flaw permitted the Exim run-time user to cause root to append to
315 arbitrary files of the attacker's choosing, with the content based
316 on content supplied by the attacker.
317
318 2. Exim now supports loading some lookup types at run-time, using your
319 platform's dlopen() functionality. This has limited platform support
320 and the intention is not to support every variant, it's limited to
321 dlopen(). This permits the main Exim binary to not be linked against
322 all the libraries needed for all the lookup types.
323
324
325 Version 4.73
326 ------------
327
328 NOTE: this version is not guaranteed backwards-compatible, please read the
329 items below carefully
330
331 1. A new main configuration option, "openssl_options", is available if Exim
332 is built with SSL support provided by OpenSSL. The option allows
333 administrators to specify OpenSSL options to be used on connections;
334 typically this is to set bug compatibility features which the OpenSSL
335 developers have not enabled by default. There may be security
336 consequences for certain options, so these should not be changed
337 frivolously.
338
339 2. A new pipe transport option, "permit_coredumps", may help with problem
340 diagnosis in some scenarios. Note that Exim is typically installed as
341 a setuid binary, which on most OSes will inhibit coredumps by default,
342 so that safety mechanism would have to be overridden for this option to
343 be able to take effect.
344
345 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
346 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
347 Note that this switches Exim to use a new API ("INSTREAM") and a future
348 release of ClamAV will remove support for the old API ("STREAM").
349
350 The av_scanner option, when set to "clamd", now takes an optional third
351 part, "local", which causes Exim to pass a filename to ClamAV instead of
352 the file content. This is the same behaviour as when clamd is pointed at
353 a Unix-domain socket. For example:
354
355 av_scanner = clamd:192.0.2.3 1234:local
356
357 ClamAV's ExtendedDetectionInfo response format is now handled.
358
359 4. There is now a -bmalware option, restricted to admin users. This option
360 takes one parameter, a filename, and scans that file with Exim's
361 malware-scanning framework. This is intended purely as a debugging aid
362 to ensure that Exim's scanning is working, not to replace other tools.
363 Note that the ACL framework is not invoked, so if av_scanner references
364 ACL variables without a fallback then this will fail.
365
366 5. There is a new expansion operator, "reverse_ip", which will reverse IP
367 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
368
369 ${reverse_ip:192.0.2.4}
370 -> 4.2.0.192
371 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
372 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
373
374 6. There is a new ACL control called "debug", to enable debug logging.
375 This allows selective logging of certain incoming transactions within
376 production environments, with some care. It takes two options, "tag"
377 and "opts"; "tag" is included in the filename of the log and "opts"
378 is used as per the -d<options> command-line option. Examples, which
379 don't all make sense in all contexts:
380
381 control = debug
382 control = debug/tag=.$sender_host_address
383 control = debug/opts=+expand+acl
384 control = debug/tag=.$message_exim_id/opts=+expand
385
386 7. It has always been implicit in the design and the documentation that
387 "the Exim user" is not root. src/EDITME said that using root was
388 "very strongly discouraged". This is not enough to keep people from
389 shooting themselves in the foot in days when many don't configure Exim
390 themselves but via package build managers. The security consequences of
391 running various bits of network code are severe if there should be bugs in
392 them. As such, the Exim user may no longer be root. If configured
393 statically, Exim will refuse to build. If configured as ref:user then Exim
394 will exit shortly after start-up. If you must shoot yourself in the foot,
395 then henceforth you will have to maintain your own local patches to strip
396 the safeties off.
397
398 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
399 condition logic to determine truth/failure and will fail to expand many
400 strings, bool_lax{} uses the router condition logic, where most strings
401 do evaluate true.
402 Note: bool{00} is false, bool_lax{00} is true.
403
404 9. Routers now support multiple "condition" tests.
405
406 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
407 Setting this allows an admin to define which entry in the tcpwrappers
408 config file will be used to control access to the daemon. This option
409 is only available when Exim is built with USE_TCP_WRAPPERS. The
410 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
411 build option.
412
413 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
414 the Exim run-time user, instead of root.
415
416 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
417 is forced on. This is mitigated by the new build option
418 TRUSTED_CONFIG_LIST which defines a list of configuration files which
419 are trusted; one per line. If a config file is owned by root and matches
420 a pathname in the list, then it may be invoked by the Exim build-time
421 user without Exim relinquishing root privileges.
422
423 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
424 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
425 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
426 include the main config. As a transition mechanism, we are temporarily
427 providing a work-around: the new build option WHITELIST_D_MACROS provides
428 a colon-separated list of macro names which may be overridden by the Exim
429 run-time user. The values of these macros are constrained to the regex
430 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
431
432
433 Version 4.72
434 ------------
435
436 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
437 writable, the other to locking of MBX folders (not mbox).
438
439 2. MySQL stored procedures are now supported.
440
441 3. The dkim_domain transport option is now a list, not a single string, and
442 messages will be signed for each element in the list (discarding
443 duplicates).
444
445 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
446 in the presence of multiple character strings within the RR. Prior to 4.70,
447 only the first string would be returned. The dnsdb lookup now, by default,
448 preserves the pre-4.70 semantics, but also now takes an extended output
449 separator specification. The separator can be followed by a semicolon, to
450 concatenate the individual text strings together with no join character,
451 or by a comma and a second separator character, in which case the text
452 strings within a TXT record are joined on that second character.
453 Administrators are reminded that DNS provides no ordering guarantees
454 between multiple records in an RRset. For example:
455
456 foo.example. IN TXT "a" "b" "c"
457 foo.example. IN TXT "d" "e" "f"
458
459 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
460 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
461 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
462
463
464 Version 4.70 / 4.71
465 -------------------
466
467 1. Native DKIM support without an external library.
468 (Note that if no action to prevent it is taken, a straight upgrade will
469 result in DKIM verification of all signed incoming emails. See spec
470 for details on conditionally disabling)
471
472 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
473
474 3. There is now a bool{} expansion condition which maps certain strings to
475 true/false condition values (most likely of use in conjunction with the
476 and{} expansion operator).
477
478 4. The $spam_score, $spam_bar and $spam_report variables are now available
479 at delivery time.
480
481 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
482 options, provided that Exim is invoked by an admin_user.
483
484 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
485 which increases compatibility with older clients at the cost of decreased
486 security. Don't set this unless you need to support such clients.
487
488 7. There is a new expansion operator, ${randint:...} which will produce a
489 "random" number less than the supplied integer. This randomness is
490 not guaranteed to be cryptographically strong, but depending upon how
491 Exim was built may be better than the most naive schemes.
492
493 8. Exim now explicitly ensures that SHA256 is available when linked against
494 OpenSSL.
495
496 9. The transport_filter_timeout option now applies to SMTP transports too.
497
498
499 Version 4.69
500 ------------
501
502 1. Preliminary DKIM support in Experimental.
503
504
505 Version 4.68
506 ------------
507
508 1. The body_linecount and body_zerocount C variables are now exported in the
509 local_scan API.
510
511 2. When a dnslists lookup succeeds, the key that was looked up is now placed
512 in $dnslist_matched. When the key is an IP address, it is not reversed in
513 this variable (though it is, of course, in the actual lookup). In simple
514 cases, for example:
515
516 deny dnslists = spamhaus.example
517
518 the key is also available in another variable (in this case,
519 $sender_host_address). In more complicated cases, however, this is not
520 true. For example, using a data lookup might generate a dnslists lookup
521 like this:
522
523 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
524
525 If this condition succeeds, the value in $dnslist_matched might be
526 192.168.6.7 (for example).
527
528 3. Authenticators now have a client_condition option. When Exim is running as
529 a client, it skips an authenticator whose client_condition expansion yields
530 "0", "no", or "false". This can be used, for example, to skip plain text
531 authenticators when the connection is not encrypted by a setting such as:
532
533 client_condition = ${if !eq{$tls_cipher}{}}
534
535 Note that the 4.67 documentation states that $tls_cipher contains the
536 cipher used for incoming messages. In fact, during SMTP delivery, it
537 contains the cipher used for the delivery. The same is true for
538 $tls_peerdn.
539
540 4. There is now a -Mvc <message-id> option, which outputs a copy of the
541 message to the standard output, in RFC 2822 format. The option can be used
542 only by an admin user.
543
544 5. There is now a /noupdate option for the ratelimit ACL condition. It
545 computes the rate and checks the limit as normal, but it does not update
546 the saved data. This means that, in relevant ACLs, it is possible to lookup
547 the existence of a specified (or auto-generated) ratelimit key without
548 incrementing the ratelimit counter for that key.
549
550 In order for this to be useful, another ACL entry must set the rate
551 for the same key somewhere (otherwise it will always be zero).
552
553 Example:
554
555 acl_check_connect:
556 # Read the rate; if it doesn't exist or is below the maximum
557 # we update it below
558 deny ratelimit = 100 / 5m / strict / noupdate
559 log_message = RATE: $sender_rate / $sender_rate_period \
560 (max $sender_rate_limit)
561
562 [... some other logic and tests...]
563
564 warn ratelimit = 100 / 5m / strict / per_cmd
565 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
566 (max $sender_rate_limit)
567 condition = ${if le{$sender_rate}{$sender_rate_limit}}
568
569 accept
570
571 6. The variable $max_received_linelength contains the number of bytes in the
572 longest line that was received as part of the message, not counting the
573 line termination character(s).
574
575 7. Host lists can now include +ignore_defer and +include_defer, analagous to
576 +ignore_unknown and +include_unknown. These options should be used with
577 care, probably only in non-critical host lists such as whitelists.
578
579 8. There's a new option called queue_only_load_latch, which defaults true.
580 If set false when queue_only_load is greater than zero, Exim re-evaluates
581 the load for each incoming message in an SMTP session. Otherwise, once one
582 message is queued, the remainder are also.
583
584 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
585 cases when an SMTP session ends without sending QUIT. However, when Exim
586 itself is is bad trouble, such as being unable to write to its log files,
587 this ACL is not run, because it might try to do things (such as write to
588 log files) that make the situation even worse.
589
590 Like the QUIT ACL, this new ACL is provided to make it possible to gather
591 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
592 modifier is forbidden in this ACL.
593
594 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
595 to a string that indicates the reason for the termination of the SMTP
596 connection. The possible values are:
597
598 acl-drop Another ACL issued a "drop" command
599 bad-commands Too many unknown or non-mail commands
600 command-timeout Timeout while reading SMTP commands
601 connection-lost The SMTP connection has been lost
602 data-timeout Timeout while reading message data
603 local-scan-error The local_scan() function crashed
604 local-scan-timeout The local_scan() function timed out
605 signal-exit SIGTERM or SIGINT
606 synchronization-error SMTP synchronization error
607 tls-failed TLS failed to start
608
609 In most cases when an SMTP connection is closed without having received
610 QUIT, Exim sends an SMTP response message before actually closing the
611 connection. With the exception of acl-drop, the default message can be
612 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
613 "drop" verb in another ACL, it is the message from the other ACL that is
614 used.
615
616 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
617 servers with individual queries. This is done by starting the query with
618 "servers=x:y:z;", where each item in the list may take one of two forms:
619
620 (1) If it is just a host name, the appropriate global option (mysql_servers
621 or pgsql_servers) is searched for a host of the same name, and the
622 remaining parameters (database, user, password) are taken from there.
623
624 (2) If it contains any slashes, it is taken as a complete parameter set.
625
626 The list of servers is used in exactly the same was as the global list.
627 Once a connection to a server has happened and a query has been
628 successfully executed, processing of the lookup ceases.
629
630 This feature is intended for use in master/slave situations where updates
631 are occurring, and one wants to update a master rather than a slave. If the
632 masters are in the list for reading, you might have:
633
634 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
635
636 In an updating lookup, you could then write
637
638 ${lookup mysql{servers=master; UPDATE ...}
639
640 If, on the other hand, the master is not to be used for reading lookups:
641
642 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
643
644 you can still update the master by
645
646 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
647
648 11. The message_body_newlines option (default FALSE, for backwards
649 compatibility) can be used to control whether newlines are present in
650 $message_body and $message_body_end. If it is FALSE, they are replaced by
651 spaces.
652
653
654 Version 4.67
655 ------------
656
657 1. There is a new log selector called smtp_no_mail, which is not included in
658 the default setting. When it is set, a line is written to the main log
659 whenever an accepted SMTP connection terminates without having issued a
660 MAIL command.
661
662 2. When an item in a dnslists list is followed by = and & and a list of IP
663 addresses, the behaviour was not clear when the lookup returned more than
664 one IP address. This has been solved by the addition of == and =& for "all"
665 rather than the default "any" matching.
666
667 3. Up till now, the only control over which cipher suites GnuTLS uses has been
668 for the cipher algorithms. New options have been added to allow some of the
669 other parameters to be varied.
670
671 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
672 set, Exim compiles a runtime option called disable_fsync.
673
674 5. There is a new variable called $smtp_count_at_connection_start.
675
676 6. There's a new control called no_pipelining.
677
678 7. There are two new variables called $sending_ip_address and $sending_port.
679 These are set whenever an SMTP connection to another host has been set up.
680
681 8. The expansion of the helo_data option in the smtp transport now happens
682 after the connection to the server has been made.
683
684 9. There is a new expansion operator ${rfc2047d: that decodes strings that
685 are encoded as per RFC 2047.
686
687 10. There is a new log selector called "pid", which causes the current process
688 id to be added to every log line, in square brackets, immediately after the
689 time and date.
690
691 11. Exim has been modified so that it flushes SMTP output before implementing
692 a delay in an ACL. It also flushes the output before performing a callout,
693 as this can take a substantial time. These behaviours can be disabled by
694 obeying control = no_delay_flush or control = no_callout_flush,
695 respectively, at some earlier stage of the connection.
696
697 12. There are two new expansion conditions that iterate over a list. They are
698 called forany and forall.
699
700 13. There's a new global option called dsn_from that can be used to vary the
701 contents of From: lines in bounces and other automatically generated
702 messages ("delivery status notifications" - hence the name of the option).
703
704 14. The smtp transport has a new option called hosts_avoid_pipelining.
705
706 15. By default, exigrep does case-insensitive matches. There is now a -I option
707 that makes it case-sensitive.
708
709 16. A number of new features ("addresses", "map", "filter", and "reduce") have
710 been added to string expansions to make it easier to process lists of
711 items, typically addresses.
712
713 17. There's a new ACL modifier called "continue". It does nothing of itself,
714 and processing of the ACL always continues with the next condition or
715 modifier. It is provided so that the side effects of expanding its argument
716 can be used.
717
718 18. It is now possible to use newline and other control characters (those with
719 values less than 32, plus DEL) as separators in lists.
720
721 19. The exigrep utility now has a -v option, which inverts the matching
722 condition.
723
724 20. The host_find_failed option in the manualroute router can now be set to
725 "ignore".
726
727
728 Version 4.66
729 ------------
730
731 No new features were added to 4.66.
732
733
734 Version 4.65
735 ------------
736
737 No new features were added to 4.65.
738
739
740 Version 4.64
741 ------------
742
743 1. ACL variables can now be given arbitrary names, as long as they start with
744 "acl_c" or "acl_m" (for connection variables and message variables), are at
745 least six characters long, with the sixth character being either a digit or
746 an underscore.
747
748 2. There is a new ACL modifier called log_reject_target. It makes it possible
749 to specify which logs are used for messages about ACL rejections.
750
751 3. There is a new authenticator called "dovecot". This is an interface to the
752 authentication facility of the Dovecot POP/IMAP server, which can support a
753 number of authentication methods.
754
755 4. The variable $message_headers_raw provides a concatenation of all the
756 messages's headers without any decoding. This is in contrast to
757 $message_headers, which does RFC2047 decoding on the header contents.
758
759 5. In a DNS black list, if two domain names, comma-separated, are given, the
760 second is used first to do an initial check, making use of any IP value
761 restrictions that are set. If there is a match, the first domain is used,
762 without any IP value restrictions, to get the TXT record.
763
764 6. All authenticators now have a server_condition option.
765
766 7. There is a new command-line option called -Mset. It is useful only in
767 conjunction with -be (that is, when testing string expansions). It must be
768 followed by a message id; Exim loads the given message from its spool
769 before doing the expansions.
770
771 8. Another similar new command-line option is called -bem. It operates like
772 -be except that it must be followed by the name of a file that contains a
773 message.
774
775 9. When an address is delayed because of a 4xx response to a RCPT command, it
776 is now the combination of sender and recipient that is delayed in
777 subsequent queue runs until its retry time is reached.
778
779 10. Unary negation and the bitwise logical operators and, or, xor, not, and
780 shift, have been added to the eval: and eval10: expansion items.
781
782 11. The variables $interface_address and $interface_port have been renamed
783 as $received_ip_address and $received_port, to make it clear that they
784 relate to message reception rather than delivery. (The old names remain
785 available for compatibility.)
786
787 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
788 to vary the message that is sent when an SMTP command is accepted.
789
790
791 Version 4.63
792 ------------
793
794 1. There is a new Boolean option called filter_prepend_home for the redirect
795 router.
796
797 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
798 start of receiving a non-SMTP message, before any of the message has been
799 read.
800
801 3. When an SMTP error message is specified in a "message" modifier in an ACL,
802 or in a :fail: or :defer: message in a redirect router, Exim now checks the
803 start of the message for an SMTP error code.
804
805 4. There is a new parameter for LDAP lookups called "referrals", which takes
806 one of the settings "follow" (the default) or "nofollow".
807
808 5. Version 20070721.2 of exipick now included, offering these new options:
809 --reverse
810 After all other sorting options have bee processed, reverse order
811 before displaying messages (-R is synonym).
812 --random
813 Randomize order of matching messages before displaying.
814 --size
815 Instead of displaying the matching messages, display the sum
816 of their sizes.
817 --sort <variable>[,<variable>...]
818 Before displaying matching messages, sort the messages according to
819 each messages value for each variable.
820 --not
821 Negate the value for every test (returns inverse output from the
822 same criteria without --not).
823
824
825 Version 4.62
826 ------------
827
828 1. The ${readsocket expansion item now supports Internet domain sockets as well
829 as Unix domain sockets. If the first argument begins "inet:", it must be of
830 the form "inet:host:port". The port is mandatory; it may be a number or the
831 name of a TCP port in /etc/services. The host may be a name, or it may be an
832 IP address. An ip address may optionally be enclosed in square brackets.
833 This is best for IPv6 addresses. For example:
834
835 ${readsocket{inet:[::1]:1234}{<request data>}...
836
837 Only a single host name may be given, but if looking it up yield more than
838 one IP address, they are each tried in turn until a connection is made. Once
839 a connection has been made, the behaviour is as for ${readsocket with a Unix
840 domain socket.
841
842 2. If a redirect router sets up file or pipe deliveries for more than one
843 incoming address, and the relevant transport has batch_max set greater than
844 one, a batch delivery now occurs.
845
846 3. The appendfile transport has a new option called maildirfolder_create_regex.
847 Its value is a regular expression. For a maildir delivery, this is matched
848 against the maildir directory; if it matches, Exim ensures that a
849 maildirfolder file is created alongside the new, cur, and tmp directories.
850
851
852 Version 4.61
853 ------------
854
855 The documentation is up-to-date for the 4.61 release. Major new features since
856 the 4.60 release are:
857
858 . An option called disable_ipv6, to disable the use of IPv6 completely.
859
860 . An increase in the number of ACL variables to 20 of each type.
861
862 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
863 $2, $3, (though those are still set) because the numeric variables get used
864 for other things in complicated expansions.
865
866 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
867
868 . It is possible to use setclassresources() on some BSD OS to control the
869 resources used in pipe deliveries.
870
871 . A new ACL modifier called add_header, which can be used with any verb.
872
873 . More errors are detectable in retry rules.
874
875 There are a number of other additions too.
876
877
878 Version 4.60
879 ------------
880
881 The documentation is up-to-date for the 4.60 release. Major new features since
882 the 4.50 release are:
883
884 . Support for SQLite.
885
886 . Support for IGNOREQUOTA in LMTP.
887
888 . Extensions to the "submission mode" features.
889
890 . Support for Client SMTP Authorization (CSA).
891
892 . Support for ratelimiting hosts and users.
893
894 . New expansion items to help with the BATV "prvs" scheme.
895
896 . A "match_ip" condition, that matches an IP address against a list.
897
898 There are many more minor changes.
899
900 ****