3c58b42ef1d97fda6ee361c142b905a847c630b6
[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 4.86
10 ------------
11
12 1. Support for using the system standard CA bundle.
13
14 2. New expansion items $config_file, $config_dir, containing the file
15 and directory name of the main configuration file. Also $exim_version.
16
17 3. New "malware=" support for Avast.
18
19 4. New "spam=" variant option for Rspamd.
20
21 5. Assorted options on malware= and spam= scanners.
22
23 6. A commandline option to write a comment into the logfile.
24
25 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
26 be configured to make connections via socks5 proxies.
27
28 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for
29 the transmission of UTF-8 envelope addresses.
30
31 9. If built with EXPERIMENTAL_INTERNATIONAL, an expansion item for a commonly
32 used encoding of Maildir folder names.
33
34 10. A logging option for slow DNS lookups.
35
36 11. New ${env {<variable>}} expansion.
37
38 12. A non-SMTP authenticator using information from TLS client certificates.
39
40 13. Main option "tls_eccurve" for selecting an Elliptic Curve for TLS.
41 Patch originally by Wolfgang Breyha.
42
43
44 Version 4.85
45 ------------
46
47 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
48 DANE smtp draft to assess a secure chain of trust of the certificate
49 used to establish the TLS connection based on a TLSA record in the
50 domain of the sender.
51
52 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
53 and several new events have been created. The reason is because it has
54 been expanded beyond just firing events during the transport phase. Any
55 existing TPDA transport options will have to be rewritten to use a new
56 $event_name expansion variable in a condition. Refer to the
57 experimental-spec.txt for details and examples.
58
59 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
60 server certs used for TLS match the result of the MX lookup. It does
61 not use the same mechanism as DANE.
62
63
64 Version 4.84
65 ------------
66
67
68 Version 4.83
69 ------------
70
71 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
72 configured to expect an initial header from a proxy that will make the
73 actual external source IP:host be used in exim instead of the IP of the
74 proxy that is connecting to it.
75
76 2. New verify option header_names_ascii, which will check to make sure
77 there are no non-ASCII characters in header names. Exim itself handles
78 those non-ASCII characters, but downstream apps may not, so Exim can
79 detect and reject if those characters are present.
80
81 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
82 codepoints with valid ones.
83
84 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
85 command line and matching a regex against the return data for trigger
86 and a second regex to extract malware_name. The mail spoolfile name can
87 be included in the command line.
88
89 5. The smtp transport now supports options "tls_verify_hosts" and
90 "tls_try_verify_hosts". If either is set the certificate verification
91 is split from the encryption operation. The default remains that a failed
92 verification cancels the encryption.
93
94 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
95 lookup can now set a list of servers to use that is different from the
96 default list.
97
98 7. New command-line option -C for exiqgrep to specify alternate exim.conf
99 file when searching the queue.
100
101 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
102
103 9. Support for DNSSEC on outbound connections.
104
105 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
106 "certextract" to extract fields from them. Hash operators md5 and sha1
107 work over them for generating fingerprints, and a new sha256 operator
108 for them added.
109
110 11. PRDR is now supported dy default.
111
112 12. OCSP stapling is now supported by default.
113
114 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
115 Delivery Status Notification messages in MIME format, and negociate
116 DSN features per RFC 3461.
117
118
119 Version 4.82
120 ------------
121
122 1. New command-line option -bI:sieve will list all supported sieve extensions
123 of this Exim build on standard output, one per line.
124 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
125 query this to establish the correct list to include in the protocol's
126 SIEVE capability line.
127
128 2. If the -n option is combined with the -bP option, then the name of an
129 emitted option is not output, only the value (if visible to you).
130 For instance, "exim -n -bP pid_file_path" should just emit a pathname
131 followed by a newline, and no other text.
132
133 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
134 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
135 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
136 acceptable for security. (Option accepted but ignored if using OpenSSL).
137 Defaults to 1024, the old value. May be lowered only to 512, or raised as
138 far as you like. Raising this may hinder TLS interoperability with other
139 sites and is not currently recommended. Lowering this will permit you to
140 establish a TLS session which is not as secure as you might like.
141
142 Unless you really know what you are doing, leave it alone.
143
144 4. If not built with DISABLE_DNSSEC, Exim now has the main option
145 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
146 to send the DO flag to your recursive resolver. If you have a recursive
147 resolver, which can set the Authenticated Data (AD) flag in results, Exim
148 can now detect this. Exim does not perform validation itself, instead
149 relying upon a trusted path to the resolver.
150
151 Current status: work-in-progress; $sender_host_dnssec variable added.
152
153 5. DSCP support for outbound connections: on a transport using the smtp driver,
154 set "dscp = ef", for instance, to cause the connections to have the relevant
155 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
156
157 Similarly for inbound connections, there is a new control modifier, dscp,
158 so "warn control = dscp/ef" in the connect ACL, or after authentication.
159
160 Supported values depend upon system libraries. "exim -bI:dscp" to list the
161 ones Exim knows of. You can also set a raw number 0..0x3F.
162
163 6. The -G command-line flag is no longer ignored; it is now equivalent to an
164 ACL setting "control = suppress_local_fixups". The -L command-line flag
165 is now accepted and forces use of syslog, with the provided tag as the
166 process name. A few other flags used by Sendmail are now accepted and
167 ignored.
168
169 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
170 ACL modifier; works for single-recipient mails which are recieved on and
171 deliverable via SMTP. Using the connection made for a recipient verify,
172 if requested before the verify, or a new one made for the purpose while
173 the inbound connection is still active. The bulk of the mail item is copied
174 direct from the inbound socket to the outbound (as well as the spool file).
175 When the source notifies the end of data, the data acceptance by the destination
176 is negociated before the acceptance is sent to the source. If the destination
177 does not accept the mail item, for example due to content-scanning, the item
178 is not accepted from the source and therefore there is no need to generate
179 a bounce mail. This is of benefit when providing a secondary-MX service.
180 The downside is that delays are under the control of the ultimate destination
181 system not your own.
182
183 The Recieved-by: header on items delivered by cutthrough is generated
184 early in reception rather than at the end; this will affect any timestamp
185 included. The log line showing delivery is recorded before that showing
186 reception; it uses a new ">>" tag instead of "=>".
187
188 To support the feature, verify-callout connections can now use ESMTP and TLS.
189 The usual smtp transport options are honoured, plus a (new, default everything)
190 hosts_verify_avoid_tls.
191
192 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
193 for specific access to the information for each connection. The old names
194 are present for now but deprecated.
195
196 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
197
198 8. New expansion operators ${listnamed:name} to get the content of a named list
199 and ${listcount:string} to count the items in a list.
200
201 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
202 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
203 modules. For some situations this is desirable, but we expect admin in
204 those situations to know they want the feature. More commonly, it means
205 that GUI user modules get loaded and are broken by the setuid Exim being
206 unable to access files specified in environment variables and passed
207 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
208 unless this new option is set.
209
210 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
211 so have also added a build option which can be used to build Exim with GnuTLS
212 but without trying to use any kind of PKCS11 support. Uncomment this in the
213 Local/Makefile:
214
215 AVOID_GNUTLS_PKCS11=yes
216
217 10. The "acl = name" condition on an ACL now supports optional arguments.
218 New expansion item "${acl {name}{arg}...}" and expansion condition
219 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
220 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
221 Variable $acl_narg contains the number of arguments. If the ACL sets
222 a "message =" value this becomes the result of the expansion item,
223 or the value of $value for the expansion condition. If the ACL returns
224 accept the expansion condition is true; if reject, false. A defer
225 return results in a forced fail.
226
227 11. Routers and transports can now have multiple headers_add and headers_remove
228 option lines. The concatenated list is used.
229
230 12. New ACL modifier "remove_header" can remove headers before message gets
231 handled by routers/transports.
232
233 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
234 "aaaa" and "a" lookups is done and the full set of results returned.
235
236 14. New expansion variable $headers_added with content from ACL add_header
237 modifier (but not yet added to messsage).
238
239 15. New 8bitmime status logging option for received messages. Log field "M8S".
240
241 16. New authenticated_sender logging option, adding to log field "A".
242
243 17. New expansion variables $router_name and $transport_name. Useful
244 particularly for debug_print as -bt commandline option does not
245 require privilege whereas -d does.
246
247 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
248 proposed extension to SMTP from Eric Hall.
249
250 19. The pipe transport has gained the force_command option, to allow
251 decorating commands from user .forward pipe aliases with prefix
252 wrappers, for instance.
253
254 20. Callout connections can now AUTH; the same controls as normal delivery
255 connections apply.
256
257 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
258 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
259 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
260 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
261 dmarc_status. It adds new control flags dmarc_disable_verify and
262 dmarc_enable_forensic.
263
264 22. Add expansion variable $authenticated_fail_id, which is the username
265 provided to the authentication method which failed. It is available
266 for use in subsequent ACL processing (typically quit or notquit ACLs).
267
268 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
269 UDP host and port.
270
271 24. New ${hexquote:..string..} expansion operator converts non-printable
272 characters in the string to \xNN form.
273
274 25. Experimental TPDA (Transport Post Delivery Action) function added.
275 Patch provided by Axel Rau.
276
277 26. Experimental Redis lookup added. Patch provided by Warren Baker.
278
279
280 Version 4.80
281 ------------
282
283 1. New authenticator driver, "gsasl". Server-only (at present).
284 This is a SASL interface, licensed under GPL, which can be found at
285 http://www.gnu.org/software/gsasl/.
286 This system does not provide sources of data for authentication, so
287 careful use needs to be made of the conditions in Exim.
288
289 2. New authenticator driver, "heimdal_gssapi". Server-only.
290 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
291 is no longer honoured for setuid programs by Heimdal. Use the
292 "server_keytab" option to point to the keytab.
293
294 3. The "pkg-config" system can now be used when building Exim to reference
295 cflags and library information for lookups and authenticators, rather
296 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
297 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
298 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
299
300 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
301 find the headers and libraries for PCRE.
302
303 4. New expansion variable $tls_bits.
304
305 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
306 be joined together with ASCII NUL characters to construct the key to pass
307 into the DBM library. Can be used with gsasl to access sasldb2 files as
308 used by Cyrus SASL.
309
310 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
311
312 Avoid release 1.0.1a if you can. Note that the default value of
313 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
314 increased susceptibility to attack. This may still have interoperability
315 implications for very old clients (see version 4.31 change 37) but
316 administrators can choose to make the trade-off themselves and restore
317 compatibility at the cost of session security.
318
319 7. Use of the new expansion variable $tls_sni in the main configuration option
320 tls_certificate will cause Exim to re-expand the option, if the client
321 sends the TLS Server Name Indication extension, to permit choosing a
322 different certificate; tls_privatekey will also be re-expanded. You must
323 still set these options to expand to valid files when $tls_sni is not set.
324
325 The SMTP Transport has gained the option tls_sni, which will set a hostname
326 for outbound TLS sessions, and set $tls_sni too.
327
328 A new log_selector, +tls_sni, has been added, to log received SNI values
329 for Exim as a server.
330
331 8. The existing "accept_8bitmime" option now defaults to true. This means
332 that Exim is deliberately not strictly RFC compliant. We're following
333 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
334 Those who disagree, or know that they are talking to mail servers that,
335 even today, are not 8-bit clean, need to turn off this option.
336
337 9. Exim can now be started with -bw (with an optional timeout, given as
338 -bw<timespec>). With this, stdin at startup is a socket that is
339 already listening for connections. This has a more modern name of
340 "socket activation", but forcing the activated socket to fd 0. We're
341 interested in adding more support for modern variants.
342
343 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
344 for numbers indicates multiplication by 1024^3.
345
346 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
347 gnutls_require_mac & gnutls_require_protocols are no longer supported.
348 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
349 string, documentation for which is at:
350 http://www.gnutls.org/manual/html_node/Priority-Strings.html
351
352 SNI support has been added to Exim's GnuTLS integration too.
353
354 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
355 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
356
357 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
358 is now available. If the contents of the file are valid, then Exim will
359 send that back in response to a TLS status request; this is OCSP Stapling.
360 Exim will not maintain the contents of the file in any way: administrators
361 are responsible for ensuring that it is up-to-date.
362
363 See "experimental-spec.txt" for more details.
364
365 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
366 identically to TXT record lookups.
367
368 14. New expansion variable $tod_epoch_l for higher-precision time.
369
370 15. New global option tls_dh_max_bits, defaulting to current value of NSS
371 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
372 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
373
374 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
375 Option can now be a path or an identifier for a standard prime.
376 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
377 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
378 primes.
379
380 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
381 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
382 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
383
384
385 Version 4.77
386 ------------
387
388 1. New options for the ratelimit ACL condition: /count= and /unique=.
389 The /noupdate option has been replaced by a /readonly option.
390
391 2. The SMTP transport's protocol option may now be set to "smtps", to
392 use SSL-on-connect outbound.
393
394 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
395 there is a problem talking to the AV scanner, or the AV scanner running.
396
397 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
398 and check if the search item is a member of the list. This does not
399 support named lists, but does subject the list part to string expansion.
400
401 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
402 built, Exim no longer performs string expansion on the second string of
403 the match_* expansion conditions: "match_address", "match_domain",
404 "match_ip" & "match_local_part". Named lists can still be used.
405
406
407 Version 4.76
408 ------------
409
410 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
411 or off in the resolver library.
412
413
414 Version 4.75
415 ------------
416
417 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
418 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
419 libraries. The following global options have been added in support of
420 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
421 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
422
423 2. The pipe transport now takes a boolean option, "freeze_signal", default
424 false. When true, if the external delivery command exits on a signal then
425 Exim will freeze the message in the queue, instead of generating a bounce.
426
427 3. Log filenames may now use %M as an escape, instead of %D (still available).
428 The %M pattern expands to yyyymm, providing month-level resolution.
429
430 4. The $message_linecount variable is now updated for the maildir_tag option,
431 in the same way as $message_size, to reflect the real number of lines,
432 including any header additions or removals from transport.
433
434 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
435 Exim now selects entries randomly, to better scale in a cluster setup.
436
437
438 Version 4.74
439 ------------
440
441 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
442 the flaw permitted the Exim run-time user to cause root to append to
443 arbitrary files of the attacker's choosing, with the content based
444 on content supplied by the attacker.
445
446 2. Exim now supports loading some lookup types at run-time, using your
447 platform's dlopen() functionality. This has limited platform support
448 and the intention is not to support every variant, it's limited to
449 dlopen(). This permits the main Exim binary to not be linked against
450 all the libraries needed for all the lookup types.
451
452
453 Version 4.73
454 ------------
455
456 NOTE: this version is not guaranteed backwards-compatible, please read the
457 items below carefully
458
459 1. A new main configuration option, "openssl_options", is available if Exim
460 is built with SSL support provided by OpenSSL. The option allows
461 administrators to specify OpenSSL options to be used on connections;
462 typically this is to set bug compatibility features which the OpenSSL
463 developers have not enabled by default. There may be security
464 consequences for certain options, so these should not be changed
465 frivolously.
466
467 2. A new pipe transport option, "permit_coredumps", may help with problem
468 diagnosis in some scenarios. Note that Exim is typically installed as
469 a setuid binary, which on most OSes will inhibit coredumps by default,
470 so that safety mechanism would have to be overridden for this option to
471 be able to take effect.
472
473 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
474 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
475 Note that this switches Exim to use a new API ("INSTREAM") and a future
476 release of ClamAV will remove support for the old API ("STREAM").
477
478 The av_scanner option, when set to "clamd", now takes an optional third
479 part, "local", which causes Exim to pass a filename to ClamAV instead of
480 the file content. This is the same behaviour as when clamd is pointed at
481 a Unix-domain socket. For example:
482
483 av_scanner = clamd:192.0.2.3 1234:local
484
485 ClamAV's ExtendedDetectionInfo response format is now handled.
486
487 4. There is now a -bmalware option, restricted to admin users. This option
488 takes one parameter, a filename, and scans that file with Exim's
489 malware-scanning framework. This is intended purely as a debugging aid
490 to ensure that Exim's scanning is working, not to replace other tools.
491 Note that the ACL framework is not invoked, so if av_scanner references
492 ACL variables without a fallback then this will fail.
493
494 5. There is a new expansion operator, "reverse_ip", which will reverse IP
495 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
496
497 ${reverse_ip:192.0.2.4}
498 -> 4.2.0.192
499 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
500 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
501
502 6. There is a new ACL control called "debug", to enable debug logging.
503 This allows selective logging of certain incoming transactions within
504 production environments, with some care. It takes two options, "tag"
505 and "opts"; "tag" is included in the filename of the log and "opts"
506 is used as per the -d<options> command-line option. Examples, which
507 don't all make sense in all contexts:
508
509 control = debug
510 control = debug/tag=.$sender_host_address
511 control = debug/opts=+expand+acl
512 control = debug/tag=.$message_exim_id/opts=+expand
513
514 7. It has always been implicit in the design and the documentation that
515 "the Exim user" is not root. src/EDITME said that using root was
516 "very strongly discouraged". This is not enough to keep people from
517 shooting themselves in the foot in days when many don't configure Exim
518 themselves but via package build managers. The security consequences of
519 running various bits of network code are severe if there should be bugs in
520 them. As such, the Exim user may no longer be root. If configured
521 statically, Exim will refuse to build. If configured as ref:user then Exim
522 will exit shortly after start-up. If you must shoot yourself in the foot,
523 then henceforth you will have to maintain your own local patches to strip
524 the safeties off.
525
526 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
527 condition logic to determine truth/failure and will fail to expand many
528 strings, bool_lax{} uses the router condition logic, where most strings
529 do evaluate true.
530 Note: bool{00} is false, bool_lax{00} is true.
531
532 9. Routers now support multiple "condition" tests.
533
534 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
535 Setting this allows an admin to define which entry in the tcpwrappers
536 config file will be used to control access to the daemon. This option
537 is only available when Exim is built with USE_TCP_WRAPPERS. The
538 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
539 build option.
540
541 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
542 the Exim run-time user, instead of root.
543
544 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
545 is forced on. This is mitigated by the new build option
546 TRUSTED_CONFIG_LIST which defines a list of configuration files which
547 are trusted; one per line. If a config file is owned by root and matches
548 a pathname in the list, then it may be invoked by the Exim build-time
549 user without Exim relinquishing root privileges.
550
551 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
552 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
553 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
554 include the main config. As a transition mechanism, we are temporarily
555 providing a work-around: the new build option WHITELIST_D_MACROS provides
556 a colon-separated list of macro names which may be overridden by the Exim
557 run-time user. The values of these macros are constrained to the regex
558 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
559
560
561 Version 4.72
562 ------------
563
564 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
565 writable, the other to locking of MBX folders (not mbox).
566
567 2. MySQL stored procedures are now supported.
568
569 3. The dkim_domain transport option is now a list, not a single string, and
570 messages will be signed for each element in the list (discarding
571 duplicates).
572
573 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
574 in the presence of multiple character strings within the RR. Prior to 4.70,
575 only the first string would be returned. The dnsdb lookup now, by default,
576 preserves the pre-4.70 semantics, but also now takes an extended output
577 separator specification. The separator can be followed by a semicolon, to
578 concatenate the individual text strings together with no join character,
579 or by a comma and a second separator character, in which case the text
580 strings within a TXT record are joined on that second character.
581 Administrators are reminded that DNS provides no ordering guarantees
582 between multiple records in an RRset. For example:
583
584 foo.example. IN TXT "a" "b" "c"
585 foo.example. IN TXT "d" "e" "f"
586
587 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
588 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
589 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
590
591
592 Version 4.70 / 4.71
593 -------------------
594
595 1. Native DKIM support without an external library.
596 (Note that if no action to prevent it is taken, a straight upgrade will
597 result in DKIM verification of all signed incoming emails. See spec
598 for details on conditionally disabling)
599
600 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
601
602 3. There is now a bool{} expansion condition which maps certain strings to
603 true/false condition values (most likely of use in conjunction with the
604 and{} expansion operator).
605
606 4. The $spam_score, $spam_bar and $spam_report variables are now available
607 at delivery time.
608
609 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
610 options, provided that Exim is invoked by an admin_user.
611
612 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
613 which increases compatibility with older clients at the cost of decreased
614 security. Don't set this unless you need to support such clients.
615
616 7. There is a new expansion operator, ${randint:...} which will produce a
617 "random" number less than the supplied integer. This randomness is
618 not guaranteed to be cryptographically strong, but depending upon how
619 Exim was built may be better than the most naive schemes.
620
621 8. Exim now explicitly ensures that SHA256 is available when linked against
622 OpenSSL.
623
624 9. The transport_filter_timeout option now applies to SMTP transports too.
625
626
627 Version 4.69
628 ------------
629
630 1. Preliminary DKIM support in Experimental.
631
632
633 Version 4.68
634 ------------
635
636 1. The body_linecount and body_zerocount C variables are now exported in the
637 local_scan API.
638
639 2. When a dnslists lookup succeeds, the key that was looked up is now placed
640 in $dnslist_matched. When the key is an IP address, it is not reversed in
641 this variable (though it is, of course, in the actual lookup). In simple
642 cases, for example:
643
644 deny dnslists = spamhaus.example
645
646 the key is also available in another variable (in this case,
647 $sender_host_address). In more complicated cases, however, this is not
648 true. For example, using a data lookup might generate a dnslists lookup
649 like this:
650
651 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
652
653 If this condition succeeds, the value in $dnslist_matched might be
654 192.168.6.7 (for example).
655
656 3. Authenticators now have a client_condition option. When Exim is running as
657 a client, it skips an authenticator whose client_condition expansion yields
658 "0", "no", or "false". This can be used, for example, to skip plain text
659 authenticators when the connection is not encrypted by a setting such as:
660
661 client_condition = ${if !eq{$tls_cipher}{}}
662
663 Note that the 4.67 documentation states that $tls_cipher contains the
664 cipher used for incoming messages. In fact, during SMTP delivery, it
665 contains the cipher used for the delivery. The same is true for
666 $tls_peerdn.
667
668 4. There is now a -Mvc <message-id> option, which outputs a copy of the
669 message to the standard output, in RFC 2822 format. The option can be used
670 only by an admin user.
671
672 5. There is now a /noupdate option for the ratelimit ACL condition. It
673 computes the rate and checks the limit as normal, but it does not update
674 the saved data. This means that, in relevant ACLs, it is possible to lookup
675 the existence of a specified (or auto-generated) ratelimit key without
676 incrementing the ratelimit counter for that key.
677
678 In order for this to be useful, another ACL entry must set the rate
679 for the same key somewhere (otherwise it will always be zero).
680
681 Example:
682
683 acl_check_connect:
684 # Read the rate; if it doesn't exist or is below the maximum
685 # we update it below
686 deny ratelimit = 100 / 5m / strict / noupdate
687 log_message = RATE: $sender_rate / $sender_rate_period \
688 (max $sender_rate_limit)
689
690 [... some other logic and tests...]
691
692 warn ratelimit = 100 / 5m / strict / per_cmd
693 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
694 (max $sender_rate_limit)
695 condition = ${if le{$sender_rate}{$sender_rate_limit}}
696
697 accept
698
699 6. The variable $max_received_linelength contains the number of bytes in the
700 longest line that was received as part of the message, not counting the
701 line termination character(s).
702
703 7. Host lists can now include +ignore_defer and +include_defer, analagous to
704 +ignore_unknown and +include_unknown. These options should be used with
705 care, probably only in non-critical host lists such as whitelists.
706
707 8. There's a new option called queue_only_load_latch, which defaults true.
708 If set false when queue_only_load is greater than zero, Exim re-evaluates
709 the load for each incoming message in an SMTP session. Otherwise, once one
710 message is queued, the remainder are also.
711
712 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
713 cases when an SMTP session ends without sending QUIT. However, when Exim
714 itself is is bad trouble, such as being unable to write to its log files,
715 this ACL is not run, because it might try to do things (such as write to
716 log files) that make the situation even worse.
717
718 Like the QUIT ACL, this new ACL is provided to make it possible to gather
719 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
720 modifier is forbidden in this ACL.
721
722 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
723 to a string that indicates the reason for the termination of the SMTP
724 connection. The possible values are:
725
726 acl-drop Another ACL issued a "drop" command
727 bad-commands Too many unknown or non-mail commands
728 command-timeout Timeout while reading SMTP commands
729 connection-lost The SMTP connection has been lost
730 data-timeout Timeout while reading message data
731 local-scan-error The local_scan() function crashed
732 local-scan-timeout The local_scan() function timed out
733 signal-exit SIGTERM or SIGINT
734 synchronization-error SMTP synchronization error
735 tls-failed TLS failed to start
736
737 In most cases when an SMTP connection is closed without having received
738 QUIT, Exim sends an SMTP response message before actually closing the
739 connection. With the exception of acl-drop, the default message can be
740 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
741 "drop" verb in another ACL, it is the message from the other ACL that is
742 used.
743
744 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
745 servers with individual queries. This is done by starting the query with
746 "servers=x:y:z;", where each item in the list may take one of two forms:
747
748 (1) If it is just a host name, the appropriate global option (mysql_servers
749 or pgsql_servers) is searched for a host of the same name, and the
750 remaining parameters (database, user, password) are taken from there.
751
752 (2) If it contains any slashes, it is taken as a complete parameter set.
753
754 The list of servers is used in exactly the same was as the global list.
755 Once a connection to a server has happened and a query has been
756 successfully executed, processing of the lookup ceases.
757
758 This feature is intended for use in master/slave situations where updates
759 are occurring, and one wants to update a master rather than a slave. If the
760 masters are in the list for reading, you might have:
761
762 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
763
764 In an updating lookup, you could then write
765
766 ${lookup mysql{servers=master; UPDATE ...}
767
768 If, on the other hand, the master is not to be used for reading lookups:
769
770 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
771
772 you can still update the master by
773
774 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
775
776 11. The message_body_newlines option (default FALSE, for backwards
777 compatibility) can be used to control whether newlines are present in
778 $message_body and $message_body_end. If it is FALSE, they are replaced by
779 spaces.
780
781
782 Version 4.67
783 ------------
784
785 1. There is a new log selector called smtp_no_mail, which is not included in
786 the default setting. When it is set, a line is written to the main log
787 whenever an accepted SMTP connection terminates without having issued a
788 MAIL command.
789
790 2. When an item in a dnslists list is followed by = and & and a list of IP
791 addresses, the behaviour was not clear when the lookup returned more than
792 one IP address. This has been solved by the addition of == and =& for "all"
793 rather than the default "any" matching.
794
795 3. Up till now, the only control over which cipher suites GnuTLS uses has been
796 for the cipher algorithms. New options have been added to allow some of the
797 other parameters to be varied.
798
799 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
800 set, Exim compiles a runtime option called disable_fsync.
801
802 5. There is a new variable called $smtp_count_at_connection_start.
803
804 6. There's a new control called no_pipelining.
805
806 7. There are two new variables called $sending_ip_address and $sending_port.
807 These are set whenever an SMTP connection to another host has been set up.
808
809 8. The expansion of the helo_data option in the smtp transport now happens
810 after the connection to the server has been made.
811
812 9. There is a new expansion operator ${rfc2047d: that decodes strings that
813 are encoded as per RFC 2047.
814
815 10. There is a new log selector called "pid", which causes the current process
816 id to be added to every log line, in square brackets, immediately after the
817 time and date.
818
819 11. Exim has been modified so that it flushes SMTP output before implementing
820 a delay in an ACL. It also flushes the output before performing a callout,
821 as this can take a substantial time. These behaviours can be disabled by
822 obeying control = no_delay_flush or control = no_callout_flush,
823 respectively, at some earlier stage of the connection.
824
825 12. There are two new expansion conditions that iterate over a list. They are
826 called forany and forall.
827
828 13. There's a new global option called dsn_from that can be used to vary the
829 contents of From: lines in bounces and other automatically generated
830 messages ("delivery status notifications" - hence the name of the option).
831
832 14. The smtp transport has a new option called hosts_avoid_pipelining.
833
834 15. By default, exigrep does case-insensitive matches. There is now a -I option
835 that makes it case-sensitive.
836
837 16. A number of new features ("addresses", "map", "filter", and "reduce") have
838 been added to string expansions to make it easier to process lists of
839 items, typically addresses.
840
841 17. There's a new ACL modifier called "continue". It does nothing of itself,
842 and processing of the ACL always continues with the next condition or
843 modifier. It is provided so that the side effects of expanding its argument
844 can be used.
845
846 18. It is now possible to use newline and other control characters (those with
847 values less than 32, plus DEL) as separators in lists.
848
849 19. The exigrep utility now has a -v option, which inverts the matching
850 condition.
851
852 20. The host_find_failed option in the manualroute router can now be set to
853 "ignore".
854
855
856 Version 4.66
857 ------------
858
859 No new features were added to 4.66.
860
861
862 Version 4.65
863 ------------
864
865 No new features were added to 4.65.
866
867
868 Version 4.64
869 ------------
870
871 1. ACL variables can now be given arbitrary names, as long as they start with
872 "acl_c" or "acl_m" (for connection variables and message variables), are at
873 least six characters long, with the sixth character being either a digit or
874 an underscore.
875
876 2. There is a new ACL modifier called log_reject_target. It makes it possible
877 to specify which logs are used for messages about ACL rejections.
878
879 3. There is a new authenticator called "dovecot". This is an interface to the
880 authentication facility of the Dovecot POP/IMAP server, which can support a
881 number of authentication methods.
882
883 4. The variable $message_headers_raw provides a concatenation of all the
884 messages's headers without any decoding. This is in contrast to
885 $message_headers, which does RFC2047 decoding on the header contents.
886
887 5. In a DNS black list, if two domain names, comma-separated, are given, the
888 second is used first to do an initial check, making use of any IP value
889 restrictions that are set. If there is a match, the first domain is used,
890 without any IP value restrictions, to get the TXT record.
891
892 6. All authenticators now have a server_condition option.
893
894 7. There is a new command-line option called -Mset. It is useful only in
895 conjunction with -be (that is, when testing string expansions). It must be
896 followed by a message id; Exim loads the given message from its spool
897 before doing the expansions.
898
899 8. Another similar new command-line option is called -bem. It operates like
900 -be except that it must be followed by the name of a file that contains a
901 message.
902
903 9. When an address is delayed because of a 4xx response to a RCPT command, it
904 is now the combination of sender and recipient that is delayed in
905 subsequent queue runs until its retry time is reached.
906
907 10. Unary negation and the bitwise logical operators and, or, xor, not, and
908 shift, have been added to the eval: and eval10: expansion items.
909
910 11. The variables $interface_address and $interface_port have been renamed
911 as $received_ip_address and $received_port, to make it clear that they
912 relate to message reception rather than delivery. (The old names remain
913 available for compatibility.)
914
915 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
916 to vary the message that is sent when an SMTP command is accepted.
917
918
919 Version 4.63
920 ------------
921
922 1. There is a new Boolean option called filter_prepend_home for the redirect
923 router.
924
925 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
926 start of receiving a non-SMTP message, before any of the message has been
927 read.
928
929 3. When an SMTP error message is specified in a "message" modifier in an ACL,
930 or in a :fail: or :defer: message in a redirect router, Exim now checks the
931 start of the message for an SMTP error code.
932
933 4. There is a new parameter for LDAP lookups called "referrals", which takes
934 one of the settings "follow" (the default) or "nofollow".
935
936 5. Version 20070721.2 of exipick now included, offering these new options:
937 --reverse
938 After all other sorting options have bee processed, reverse order
939 before displaying messages (-R is synonym).
940 --random
941 Randomize order of matching messages before displaying.
942 --size
943 Instead of displaying the matching messages, display the sum
944 of their sizes.
945 --sort <variable>[,<variable>...]
946 Before displaying matching messages, sort the messages according to
947 each messages value for each variable.
948 --not
949 Negate the value for every test (returns inverse output from the
950 same criteria without --not).
951
952
953 Version 4.62
954 ------------
955
956 1. The ${readsocket expansion item now supports Internet domain sockets as well
957 as Unix domain sockets. If the first argument begins "inet:", it must be of
958 the form "inet:host:port". The port is mandatory; it may be a number or the
959 name of a TCP port in /etc/services. The host may be a name, or it may be an
960 IP address. An ip address may optionally be enclosed in square brackets.
961 This is best for IPv6 addresses. For example:
962
963 ${readsocket{inet:[::1]:1234}{<request data>}...
964
965 Only a single host name may be given, but if looking it up yield more than
966 one IP address, they are each tried in turn until a connection is made. Once
967 a connection has been made, the behaviour is as for ${readsocket with a Unix
968 domain socket.
969
970 2. If a redirect router sets up file or pipe deliveries for more than one
971 incoming address, and the relevant transport has batch_max set greater than
972 one, a batch delivery now occurs.
973
974 3. The appendfile transport has a new option called maildirfolder_create_regex.
975 Its value is a regular expression. For a maildir delivery, this is matched
976 against the maildir directory; if it matches, Exim ensures that a
977 maildirfolder file is created alongside the new, cur, and tmp directories.
978
979
980 Version 4.61
981 ------------
982
983 The documentation is up-to-date for the 4.61 release. Major new features since
984 the 4.60 release are:
985
986 . An option called disable_ipv6, to disable the use of IPv6 completely.
987
988 . An increase in the number of ACL variables to 20 of each type.
989
990 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
991 $2, $3, (though those are still set) because the numeric variables get used
992 for other things in complicated expansions.
993
994 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
995
996 . It is possible to use setclassresources() on some BSD OS to control the
997 resources used in pipe deliveries.
998
999 . A new ACL modifier called add_header, which can be used with any verb.
1000
1001 . More errors are detectable in retry rules.
1002
1003 There are a number of other additions too.
1004
1005
1006 Version 4.60
1007 ------------
1008
1009 The documentation is up-to-date for the 4.60 release. Major new features since
1010 the 4.50 release are:
1011
1012 . Support for SQLite.
1013
1014 . Support for IGNOREQUOTA in LMTP.
1015
1016 . Extensions to the "submission mode" features.
1017
1018 . Support for Client SMTP Authorization (CSA).
1019
1020 . Support for ratelimiting hosts and users.
1021
1022 . New expansion items to help with the BATV "prvs" scheme.
1023
1024 . A "match_ip" condition, that matches an IP address against a list.
1025
1026 There are many more minor changes.
1027
1028 ****