ACL modifier
[exim.git] / doc / doc-txt / NewStuff
1 New Features in Exim
2 --------------------
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.
9 Version 4.88
10 ------------
12 1. The new perl_tainmode option allows to run the embedded perl
13 interpreter in taint mode.
15 2. Facility for named queues. A commandline argument can specify
16 the queue name for a queue-runner, and an ACL modifier can set
17 the queue to be used for a message.
20 Version 4.87
21 ------------
23 1. The ACL conditions regex and mime_regex now capture substrings
24 into numeric variables $regex1 to 9, like the "match" expansion condition.
26 2. New $callout_address variable records the address used for a spam=,
27 malware= or verify= callout.
29 3. Transports now take a "max_parallel" option, to limit concurrency.
31 4. Expansion operators ${ipv6norm:<string>} and ${ipv6denorm:<string>}.
32 The latter expands to a 8-element colon-sep set of hex digits including
33 leading zeroes. A trailing ipv4-style dotted-decimal set is converted
34 to hex. Pure ipv4 addresses are converted to IPv4-mapped IPv6.
35 The former operator strips leading zeroes and collapses the longest
36 set of 0-groups to a double-colon.
38 5. New "-bP config" support, to dump the effective configuration.
40 6. New $dkim_key_length variable.
42 7. New base64d and base64 expansion items (the existing str2b64 being a
43 synonym of the latter). Add support in base64 for certificates.
45 8. New main configuration option "bounce_return_linesize_limit" to
46 avoid oversize bodies in bounces. The dafault value matches RFC
47 limits.
49 9. New $initial_cwd expansion variable.
52 Version 4.86
53 ------------
55 1. Support for using the system standard CA bundle.
57 2. New expansion items $config_file, $config_dir, containing the file
58 and directory name of the main configuration file. Also $exim_version.
60 3. New "malware=" support for Avast.
62 4. New "spam=" variant option for Rspamd.
64 5. Assorted options on malware= and spam= scanners.
66 6. A commandline option to write a comment into the logfile.
68 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
69 be configured to make connections via socks5 proxies.
71 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for
72 the transmission of UTF-8 envelope addresses.
74 9. If built with EXPERIMENTAL_INTERNATIONAL, an expansion item for a commonly
75 used encoding of Maildir folder names.
77 10. A logging option for slow DNS lookups.
79 11. New ${env {<variable>}} expansion.
81 12. A non-SMTP authenticator using information from TLS client certificates.
83 13. Main option "tls_eccurve" for selecting an Elliptic Curve for TLS.
84 Patch originally by Wolfgang Breyha.
86 14. Main option "dns_trust_aa" for trusting your local nameserver at the
87 same level as DNSSEC.
90 Version 4.85
91 ------------
93 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
94 DANE smtp draft to assess a secure chain of trust of the certificate
95 used to establish the TLS connection based on a TLSA record in the
96 domain of the sender.
98 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
99 and several new events have been created. The reason is because it has
100 been expanded beyond just firing events during the transport phase. Any
101 existing TPDA transport options will have to be rewritten to use a new
102 $event_name expansion variable in a condition. Refer to the
103 experimental-spec.txt for details and examples.
105 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
106 server certs used for TLS match the result of the MX lookup. It does
107 not use the same mechanism as DANE.
110 Version 4.84
111 ------------
114 Version 4.83
115 ------------
117 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
118 configured to expect an initial header from a proxy that will make the
119 actual external source IP:host be used in exim instead of the IP of the
120 proxy that is connecting to it.
122 2. New verify option header_names_ascii, which will check to make sure
123 there are no non-ASCII characters in header names. Exim itself handles
124 those non-ASCII characters, but downstream apps may not, so Exim can
125 detect and reject if those characters are present.
127 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
128 codepoints with valid ones.
130 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
131 command line and matching a regex against the return data for trigger
132 and a second regex to extract malware_name. The mail spoolfile name can
133 be included in the command line.
135 5. The smtp transport now supports options "tls_verify_hosts" and
136 "tls_try_verify_hosts". If either is set the certificate verification
137 is split from the encryption operation. The default remains that a failed
138 verification cancels the encryption.
140 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
141 lookup can now set a list of servers to use that is different from the
142 default list.
144 7. New command-line option -C for exiqgrep to specify alternate exim.conf
145 file when searching the queue.
147 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
149 9. Support for DNSSEC on outbound connections.
151 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
152 "certextract" to extract fields from them. Hash operators md5 and sha1
153 work over them for generating fingerprints, and a new sha256 operator
154 for them added.
156 11. PRDR is now supported dy default.
158 12. OCSP stapling is now supported by default.
160 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
161 Delivery Status Notification messages in MIME format, and negociate
162 DSN features per RFC 3461.
165 Version 4.82
166 ------------
168 1. New command-line option -bI:sieve will list all supported sieve extensions
169 of this Exim build on standard output, one per line.
170 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
171 query this to establish the correct list to include in the protocol's
172 SIEVE capability line.
174 2. If the -n option is combined with the -bP option, then the name of an
175 emitted option is not output, only the value (if visible to you).
176 For instance, "exim -n -bP pid_file_path" should just emit a pathname
177 followed by a newline, and no other text.
179 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
180 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
181 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
182 acceptable for security. (Option accepted but ignored if using OpenSSL).
183 Defaults to 1024, the old value. May be lowered only to 512, or raised as
184 far as you like. Raising this may hinder TLS interoperability with other
185 sites and is not currently recommended. Lowering this will permit you to
186 establish a TLS session which is not as secure as you might like.
188 Unless you really know what you are doing, leave it alone.
190 4. If not built with DISABLE_DNSSEC, Exim now has the main option
191 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
192 to send the DO flag to your recursive resolver. If you have a recursive
193 resolver, which can set the Authenticated Data (AD) flag in results, Exim
194 can now detect this. Exim does not perform validation itself, instead
195 relying upon a trusted path to the resolver.
197 Current status: work-in-progress; $sender_host_dnssec variable added.
199 5. DSCP support for outbound connections: on a transport using the smtp driver,
200 set "dscp = ef", for instance, to cause the connections to have the relevant
201 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
203 Similarly for inbound connections, there is a new control modifier, dscp,
204 so "warn control = dscp/ef" in the connect ACL, or after authentication.
206 Supported values depend upon system libraries. "exim -bI:dscp" to list the
207 ones Exim knows of. You can also set a raw number 0..0x3F.
209 6. The -G command-line flag is no longer ignored; it is now equivalent to an
210 ACL setting "control = suppress_local_fixups". The -L command-line flag
211 is now accepted and forces use of syslog, with the provided tag as the
212 process name. A few other flags used by Sendmail are now accepted and
213 ignored.
215 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
216 ACL modifier; works for single-recipient mails which are recieved on and
217 deliverable via SMTP. Using the connection made for a recipient verify,
218 if requested before the verify, or a new one made for the purpose while
219 the inbound connection is still active. The bulk of the mail item is copied
220 direct from the inbound socket to the outbound (as well as the spool file).
221 When the source notifies the end of data, the data acceptance by the destination
222 is negociated before the acceptance is sent to the source. If the destination
223 does not accept the mail item, for example due to content-scanning, the item
224 is not accepted from the source and therefore there is no need to generate
225 a bounce mail. This is of benefit when providing a secondary-MX service.
226 The downside is that delays are under the control of the ultimate destination
227 system not your own.
229 The Recieved-by: header on items delivered by cutthrough is generated
230 early in reception rather than at the end; this will affect any timestamp
231 included. The log line showing delivery is recorded before that showing
232 reception; it uses a new ">>" tag instead of "=>".
234 To support the feature, verify-callout connections can now use ESMTP and TLS.
235 The usual smtp transport options are honoured, plus a (new, default everything)
236 hosts_verify_avoid_tls.
238 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
239 for specific access to the information for each connection. The old names
240 are present for now but deprecated.
242 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
244 8. New expansion operators ${listnamed:name} to get the content of a named list
245 and ${listcount:string} to count the items in a list.
247 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
248 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
249 modules. For some situations this is desirable, but we expect admin in
250 those situations to know they want the feature. More commonly, it means
251 that GUI user modules get loaded and are broken by the setuid Exim being
252 unable to access files specified in environment variables and passed
253 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
254 unless this new option is set.
256 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
257 so have also added a build option which can be used to build Exim with GnuTLS
258 but without trying to use any kind of PKCS11 support. Uncomment this in the
259 Local/Makefile:
263 10. The "acl = name" condition on an ACL now supports optional arguments.
264 New expansion item "${acl {name}{arg}...}" and expansion condition
265 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
266 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
267 Variable $acl_narg contains the number of arguments. If the ACL sets
268 a "message =" value this becomes the result of the expansion item,
269 or the value of $value for the expansion condition. If the ACL returns
270 accept the expansion condition is true; if reject, false. A defer
271 return results in a forced fail.
273 11. Routers and transports can now have multiple headers_add and headers_remove
274 option lines. The concatenated list is used.
276 12. New ACL modifier "remove_header" can remove headers before message gets
277 handled by routers/transports.
279 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
280 "aaaa" and "a" lookups is done and the full set of results returned.
282 14. New expansion variable $headers_added with content from ACL add_header
283 modifier (but not yet added to message).
285 15. New 8bitmime status logging option for received messages. Log field "M8S".
287 16. New authenticated_sender logging option, adding to log field "A".
289 17. New expansion variables $router_name and $transport_name. Useful
290 particularly for debug_print as -bt commandline option does not
291 require privilege whereas -d does.
293 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
294 proposed extension to SMTP from Eric Hall.
296 19. The pipe transport has gained the force_command option, to allow
297 decorating commands from user .forward pipe aliases with prefix
298 wrappers, for instance.
300 20. Callout connections can now AUTH; the same controls as normal delivery
301 connections apply.
303 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
304 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
305 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
306 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
307 dmarc_status. It adds new control flags dmarc_disable_verify and
308 dmarc_enable_forensic.
310 22. Add expansion variable $authenticated_fail_id, which is the username
311 provided to the authentication method which failed. It is available
312 for use in subsequent ACL processing (typically quit or notquit ACLs).
314 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
315 UDP host and port.
317 24. New ${hexquote:..string..} expansion operator converts non-printable
318 characters in the string to \xNN form.
320 25. Experimental TPDA (Transport Post Delivery Action) function added.
321 Patch provided by Axel Rau.
323 26. Experimental Redis lookup added. Patch provided by Warren Baker.
326 Version 4.80
327 ------------
329 1. New authenticator driver, "gsasl". Server-only (at present).
330 This is a SASL interface, licensed under GPL, which can be found at
332 This system does not provide sources of data for authentication, so
333 careful use needs to be made of the conditions in Exim.
335 2. New authenticator driver, "heimdal_gssapi". Server-only.
336 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
337 is no longer honoured for setuid programs by Heimdal. Use the
338 "server_keytab" option to point to the keytab.
340 3. The "pkg-config" system can now be used when building Exim to reference
341 cflags and library information for lookups and authenticators, rather
342 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
343 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
344 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
346 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
347 find the headers and libraries for PCRE.
349 4. New expansion variable $tls_bits.
351 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
352 be joined together with ASCII NUL characters to construct the key to pass
353 into the DBM library. Can be used with gsasl to access sasldb2 files as
354 used by Cyrus SASL.
356 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
358 Avoid release 1.0.1a if you can. Note that the default value of
359 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
360 increased susceptibility to attack. This may still have interoperability
361 implications for very old clients (see version 4.31 change 37) but
362 administrators can choose to make the trade-off themselves and restore
363 compatibility at the cost of session security.
365 7. Use of the new expansion variable $tls_sni in the main configuration option
366 tls_certificate will cause Exim to re-expand the option, if the client
367 sends the TLS Server Name Indication extension, to permit choosing a
368 different certificate; tls_privatekey will also be re-expanded. You must
369 still set these options to expand to valid files when $tls_sni is not set.
371 The SMTP Transport has gained the option tls_sni, which will set a hostname
372 for outbound TLS sessions, and set $tls_sni too.
374 A new log_selector, +tls_sni, has been added, to log received SNI values
375 for Exim as a server.
377 8. The existing "accept_8bitmime" option now defaults to true. This means
378 that Exim is deliberately not strictly RFC compliant. We're following
379 Dan Bernstein's advice in by default.
380 Those who disagree, or know that they are talking to mail servers that,
381 even today, are not 8-bit clean, need to turn off this option.
383 9. Exim can now be started with -bw (with an optional timeout, given as
384 -bw<timespec>). With this, stdin at startup is a socket that is
385 already listening for connections. This has a more modern name of
386 "socket activation", but forcing the activated socket to fd 0. We're
387 interested in adding more support for modern variants.
389 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
390 for numbers indicates multiplication by 1024^3.
392 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
393 gnutls_require_mac & gnutls_require_protocols are no longer supported.
394 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
395 string, documentation for which is at:
398 SNI support has been added to Exim's GnuTLS integration too.
400 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
401 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
403 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
404 is now available. If the contents of the file are valid, then Exim will
405 send that back in response to a TLS status request; this is OCSP Stapling.
406 Exim will not maintain the contents of the file in any way: administrators
407 are responsible for ensuring that it is up-to-date.
409 See "experimental-spec.txt" for more details.
411 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
412 identically to TXT record lookups.
414 14. New expansion variable $tod_epoch_l for higher-precision time.
416 15. New global option tls_dh_max_bits, defaulting to current value of NSS
417 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
418 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
420 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
421 Option can now be a path or an identifier for a standard prime.
422 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
423 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
424 primes.
426 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
427 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
428 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
431 Version 4.77
432 ------------
434 1. New options for the ratelimit ACL condition: /count= and /unique=.
435 The /noupdate option has been replaced by a /readonly option.
437 2. The SMTP transport's protocol option may now be set to "smtps", to
438 use SSL-on-connect outbound.
440 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
441 there is a problem talking to the AV scanner, or the AV scanner running.
443 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
444 and check if the search item is a member of the list. This does not
445 support named lists, but does subject the list part to string expansion.
447 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
448 built, Exim no longer performs string expansion on the second string of
449 the match_* expansion conditions: "match_address", "match_domain",
450 "match_ip" & "match_local_part". Named lists can still be used.
453 Version 4.76
454 ------------
456 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
457 or off in the resolver library.
460 Version 4.75
461 ------------
463 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
464 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
465 libraries. The following global options have been added in support of
466 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
467 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
469 2. The pipe transport now takes a boolean option, "freeze_signal", default
470 false. When true, if the external delivery command exits on a signal then
471 Exim will freeze the message in the queue, instead of generating a bounce.
473 3. Log filenames may now use %M as an escape, instead of %D (still available).
474 The %M pattern expands to yyyymm, providing month-level resolution.
476 4. The $message_linecount variable is now updated for the maildir_tag option,
477 in the same way as $message_size, to reflect the real number of lines,
478 including any header additions or removals from transport.
480 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
481 Exim now selects entries randomly, to better scale in a cluster setup.
484 Version 4.74
485 ------------
487 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
488 the flaw permitted the Exim run-time user to cause root to append to
489 arbitrary files of the attacker's choosing, with the content based
490 on content supplied by the attacker.
492 2. Exim now supports loading some lookup types at run-time, using your
493 platform's dlopen() functionality. This has limited platform support
494 and the intention is not to support every variant, it's limited to
495 dlopen(). This permits the main Exim binary to not be linked against
496 all the libraries needed for all the lookup types.
499 Version 4.73
500 ------------
502 NOTE: this version is not guaranteed backwards-compatible, please read the
503 items below carefully
505 1. A new main configuration option, "openssl_options", is available if Exim
506 is built with SSL support provided by OpenSSL. The option allows
507 administrators to specify OpenSSL options to be used on connections;
508 typically this is to set bug compatibility features which the OpenSSL
509 developers have not enabled by default. There may be security
510 consequences for certain options, so these should not be changed
511 frivolously.
513 2. A new pipe transport option, "permit_coredumps", may help with problem
514 diagnosis in some scenarios. Note that Exim is typically installed as
515 a setuid binary, which on most OSes will inhibit coredumps by default,
516 so that safety mechanism would have to be overridden for this option to
517 be able to take effect.
519 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
520 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
521 Note that this switches Exim to use a new API ("INSTREAM") and a future
522 release of ClamAV will remove support for the old API ("STREAM").
524 The av_scanner option, when set to "clamd", now takes an optional third
525 part, "local", which causes Exim to pass a filename to ClamAV instead of
526 the file content. This is the same behaviour as when clamd is pointed at
527 a Unix-domain socket. For example:
529 av_scanner = clamd: 1234:local
531 ClamAV's ExtendedDetectionInfo response format is now handled.
533 4. There is now a -bmalware option, restricted to admin users. This option
534 takes one parameter, a filename, and scans that file with Exim's
535 malware-scanning framework. This is intended purely as a debugging aid
536 to ensure that Exim's scanning is working, not to replace other tools.
537 Note that the ACL framework is not invoked, so if av_scanner references
538 ACL variables without a fallback then this will fail.
540 5. There is a new expansion operator, "reverse_ip", which will reverse IP
541 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
543 ${reverse_ip:}
544 ->
545 ${reverse_ip:2001:0db8:c42:9:1:abcd:}
546 ->
548 6. There is a new ACL control called "debug", to enable debug logging.
549 This allows selective logging of certain incoming transactions within
550 production environments, with some care. It takes two options, "tag"
551 and "opts"; "tag" is included in the filename of the log and "opts"
552 is used as per the -d<options> command-line option. Examples, which
553 don't all make sense in all contexts:
555 control = debug
556 control = debug/tag=.$sender_host_address
557 control = debug/opts=+expand+acl
558 control = debug/tag=.$message_exim_id/opts=+expand
560 7. It has always been implicit in the design and the documentation that
561 "the Exim user" is not root. src/EDITME said that using root was
562 "very strongly discouraged". This is not enough to keep people from
563 shooting themselves in the foot in days when many don't configure Exim
564 themselves but via package build managers. The security consequences of
565 running various bits of network code are severe if there should be bugs in
566 them. As such, the Exim user may no longer be root. If configured
567 statically, Exim will refuse to build. If configured as ref:user then Exim
568 will exit shortly after start-up. If you must shoot yourself in the foot,
569 then henceforth you will have to maintain your own local patches to strip
570 the safeties off.
572 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
573 condition logic to determine truth/failure and will fail to expand many
574 strings, bool_lax{} uses the router condition logic, where most strings
575 do evaluate true.
576 Note: bool{00} is false, bool_lax{00} is true.
578 9. Routers now support multiple "condition" tests.
580 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
581 Setting this allows an admin to define which entry in the tcpwrappers
582 config file will be used to control access to the daemon. This option
583 is only available when Exim is built with USE_TCP_WRAPPERS. The
584 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
585 build option.
587 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
588 the Exim run-time user, instead of root.
590 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
591 is forced on. This is mitigated by the new build option
592 TRUSTED_CONFIG_LIST which defines a list of configuration files which
593 are trusted; one per line. If a config file is owned by root and matches
594 a pathname in the list, then it may be invoked by the Exim build-time
595 user without Exim relinquishing root privileges.
597 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
598 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
599 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
600 include the main config. As a transition mechanism, we are temporarily
601 providing a work-around: the new build option WHITELIST_D_MACROS provides
602 a colon-separated list of macro names which may be overridden by the Exim
603 run-time user. The values of these macros are constrained to the regex
604 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
607 Version 4.72
608 ------------
610 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
611 writable, the other to locking of MBX folders (not mbox).
613 2. MySQL stored procedures are now supported.
615 3. The dkim_domain transport option is now a list, not a single string, and
616 messages will be signed for each element in the list (discarding
617 duplicates).
619 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
620 in the presence of multiple character strings within the RR. Prior to 4.70,
621 only the first string would be returned. The dnsdb lookup now, by default,
622 preserves the pre-4.70 semantics, but also now takes an extended output
623 separator specification. The separator can be followed by a semicolon, to
624 concatenate the individual text strings together with no join character,
625 or by a comma and a second separator character, in which case the text
626 strings within a TXT record are joined on that second character.
627 Administrators are reminded that DNS provides no ordering guarantees
628 between multiple records in an RRset. For example:
630 foo.example. IN TXT "a" "b" "c"
631 foo.example. IN TXT "d" "e" "f"
633 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
634 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
635 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
638 Version 4.70 / 4.71
639 -------------------
641 1. Native DKIM support without an external library.
642 (Note that if no action to prevent it is taken, a straight upgrade will
643 result in DKIM verification of all signed incoming emails. See spec
644 for details on conditionally disabling)
646 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
648 3. There is now a bool{} expansion condition which maps certain strings to
649 true/false condition values (most likely of use in conjunction with the
650 and{} expansion operator).
652 4. The $spam_score, $spam_bar and $spam_report variables are now available
653 at delivery time.
655 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
656 options, provided that Exim is invoked by an admin_user.
658 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
659 which increases compatibility with older clients at the cost of decreased
660 security. Don't set this unless you need to support such clients.
662 7. There is a new expansion operator, ${randint:...} which will produce a
663 "random" number less than the supplied integer. This randomness is
664 not guaranteed to be cryptographically strong, but depending upon how
665 Exim was built may be better than the most naive schemes.
667 8. Exim now explicitly ensures that SHA256 is available when linked against
668 OpenSSL.
670 9. The transport_filter_timeout option now applies to SMTP transports too.
673 Version 4.69
674 ------------
676 1. Preliminary DKIM support in Experimental.
679 Version 4.68
680 ------------
682 1. The body_linecount and body_zerocount C variables are now exported in the
683 local_scan API.
685 2. When a dnslists lookup succeeds, the key that was looked up is now placed
686 in $dnslist_matched. When the key is an IP address, it is not reversed in
687 this variable (though it is, of course, in the actual lookup). In simple
688 cases, for example:
690 deny dnslists = spamhaus.example
692 the key is also available in another variable (in this case,
693 $sender_host_address). In more complicated cases, however, this is not
694 true. For example, using a data lookup might generate a dnslists lookup
695 like this:
697 deny dnslists = spamhaus.example/<|||...
699 If this condition succeeds, the value in $dnslist_matched might be
700 (for example).
702 3. Authenticators now have a client_condition option. When Exim is running as
703 a client, it skips an authenticator whose client_condition expansion yields
704 "0", "no", or "false". This can be used, for example, to skip plain text
705 authenticators when the connection is not encrypted by a setting such as:
707 client_condition = ${if !eq{$tls_cipher}{}}
709 Note that the 4.67 documentation states that $tls_cipher contains the
710 cipher used for incoming messages. In fact, during SMTP delivery, it
711 contains the cipher used for the delivery. The same is true for
712 $tls_peerdn.
714 4. There is now a -Mvc <message-id> option, which outputs a copy of the
715 message to the standard output, in RFC 2822 format. The option can be used
716 only by an admin user.
718 5. There is now a /noupdate option for the ratelimit ACL condition. It
719 computes the rate and checks the limit as normal, but it does not update
720 the saved data. This means that, in relevant ACLs, it is possible to lookup
721 the existence of a specified (or auto-generated) ratelimit key without
722 incrementing the ratelimit counter for that key.
724 In order for this to be useful, another ACL entry must set the rate
725 for the same key somewhere (otherwise it will always be zero).
727 Example:
729 acl_check_connect:
730 # Read the rate; if it doesn't exist or is below the maximum
731 # we update it below
732 deny ratelimit = 100 / 5m / strict / noupdate
733 log_message = RATE: $sender_rate / $sender_rate_period \
734 (max $sender_rate_limit)
736 [... some other logic and tests...]
738 warn ratelimit = 100 / 5m / strict / per_cmd
739 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
740 (max $sender_rate_limit)
741 condition = ${if le{$sender_rate}{$sender_rate_limit}}
743 accept
745 6. The variable $max_received_linelength contains the number of bytes in the
746 longest line that was received as part of the message, not counting the
747 line termination character(s).
749 7. Host lists can now include +ignore_defer and +include_defer, analagous to
750 +ignore_unknown and +include_unknown. These options should be used with
751 care, probably only in non-critical host lists such as whitelists.
753 8. There's a new option called queue_only_load_latch, which defaults true.
754 If set false when queue_only_load is greater than zero, Exim re-evaluates
755 the load for each incoming message in an SMTP session. Otherwise, once one
756 message is queued, the remainder are also.
758 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
759 cases when an SMTP session ends without sending QUIT. However, when Exim
760 itself is is bad trouble, such as being unable to write to its log files,
761 this ACL is not run, because it might try to do things (such as write to
762 log files) that make the situation even worse.
764 Like the QUIT ACL, this new ACL is provided to make it possible to gather
765 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
766 modifier is forbidden in this ACL.
768 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
769 to a string that indicates the reason for the termination of the SMTP
770 connection. The possible values are:
772 acl-drop Another ACL issued a "drop" command
773 bad-commands Too many unknown or non-mail commands
774 command-timeout Timeout while reading SMTP commands
775 connection-lost The SMTP connection has been lost
776 data-timeout Timeout while reading message data
777 local-scan-error The local_scan() function crashed
778 local-scan-timeout The local_scan() function timed out
779 signal-exit SIGTERM or SIGINT
780 synchronization-error SMTP synchronization error
781 tls-failed TLS failed to start
783 In most cases when an SMTP connection is closed without having received
784 QUIT, Exim sends an SMTP response message before actually closing the
785 connection. With the exception of acl-drop, the default message can be
786 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
787 "drop" verb in another ACL, it is the message from the other ACL that is
788 used.
790 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
791 servers with individual queries. This is done by starting the query with
792 "servers=x:y:z;", where each item in the list may take one of two forms:
794 (1) If it is just a host name, the appropriate global option (mysql_servers
795 or pgsql_servers) is searched for a host of the same name, and the
796 remaining parameters (database, user, password) are taken from there.
798 (2) If it contains any slashes, it is taken as a complete parameter set.
800 The list of servers is used in exactly the same was as the global list.
801 Once a connection to a server has happened and a query has been
802 successfully executed, processing of the lookup ceases.
804 This feature is intended for use in master/slave situations where updates
805 are occurring, and one wants to update a master rather than a slave. If the
806 masters are in the list for reading, you might have:
808 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
810 In an updating lookup, you could then write
812 ${lookup mysql{servers=master; UPDATE ...}
814 If, on the other hand, the master is not to be used for reading lookups:
816 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
818 you can still update the master by
820 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
822 11. The message_body_newlines option (default FALSE, for backwards
823 compatibility) can be used to control whether newlines are present in
824 $message_body and $message_body_end. If it is FALSE, they are replaced by
825 spaces.
828 Version 4.67
829 ------------
831 1. There is a new log selector called smtp_no_mail, which is not included in
832 the default setting. When it is set, a line is written to the main log
833 whenever an accepted SMTP connection terminates without having issued a
834 MAIL command.
836 2. When an item in a dnslists list is followed by = and & and a list of IP
837 addresses, the behaviour was not clear when the lookup returned more than
838 one IP address. This has been solved by the addition of == and =& for "all"
839 rather than the default "any" matching.
841 3. Up till now, the only control over which cipher suites GnuTLS uses has been
842 for the cipher algorithms. New options have been added to allow some of the
843 other parameters to be varied.
845 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
846 set, Exim compiles a runtime option called disable_fsync.
848 5. There is a new variable called $smtp_count_at_connection_start.
850 6. There's a new control called no_pipelining.
852 7. There are two new variables called $sending_ip_address and $sending_port.
853 These are set whenever an SMTP connection to another host has been set up.
855 8. The expansion of the helo_data option in the smtp transport now happens
856 after the connection to the server has been made.
858 9. There is a new expansion operator ${rfc2047d: that decodes strings that
859 are encoded as per RFC 2047.
861 10. There is a new log selector called "pid", which causes the current process
862 id to be added to every log line, in square brackets, immediately after the
863 time and date.
865 11. Exim has been modified so that it flushes SMTP output before implementing
866 a delay in an ACL. It also flushes the output before performing a callout,
867 as this can take a substantial time. These behaviours can be disabled by
868 obeying control = no_delay_flush or control = no_callout_flush,
869 respectively, at some earlier stage of the connection.
871 12. There are two new expansion conditions that iterate over a list. They are
872 called forany and forall.
874 13. There's a new global option called dsn_from that can be used to vary the
875 contents of From: lines in bounces and other automatically generated
876 messages ("delivery status notifications" - hence the name of the option).
878 14. The smtp transport has a new option called hosts_avoid_pipelining.
880 15. By default, exigrep does case-insensitive matches. There is now a -I option
881 that makes it case-sensitive.
883 16. A number of new features ("addresses", "map", "filter", and "reduce") have
884 been added to string expansions to make it easier to process lists of
885 items, typically addresses.
887 17. There's a new ACL modifier called "continue". It does nothing of itself,
888 and processing of the ACL always continues with the next condition or
889 modifier. It is provided so that the side effects of expanding its argument
890 can be used.
892 18. It is now possible to use newline and other control characters (those with
893 values less than 32, plus DEL) as separators in lists.
895 19. The exigrep utility now has a -v option, which inverts the matching
896 condition.
898 20. The host_find_failed option in the manualroute router can now be set to
899 "ignore".
902 Version 4.66
903 ------------
905 No new features were added to 4.66.
908 Version 4.65
909 ------------
911 No new features were added to 4.65.
914 Version 4.64
915 ------------
917 1. ACL variables can now be given arbitrary names, as long as they start with
918 "acl_c" or "acl_m" (for connection variables and message variables), are at
919 least six characters long, with the sixth character being either a digit or
920 an underscore.
922 2. There is a new ACL modifier called log_reject_target. It makes it possible
923 to specify which logs are used for messages about ACL rejections.
925 3. There is a new authenticator called "dovecot". This is an interface to the
926 authentication facility of the Dovecot POP/IMAP server, which can support a
927 number of authentication methods.
929 4. The variable $message_headers_raw provides a concatenation of all the
930 messages's headers without any decoding. This is in contrast to
931 $message_headers, which does RFC2047 decoding on the header contents.
933 5. In a DNS black list, if two domain names, comma-separated, are given, the
934 second is used first to do an initial check, making use of any IP value
935 restrictions that are set. If there is a match, the first domain is used,
936 without any IP value restrictions, to get the TXT record.
938 6. All authenticators now have a server_condition option.
940 7. There is a new command-line option called -Mset. It is useful only in
941 conjunction with -be (that is, when testing string expansions). It must be
942 followed by a message id; Exim loads the given message from its spool
943 before doing the expansions.
945 8. Another similar new command-line option is called -bem. It operates like
946 -be except that it must be followed by the name of a file that contains a
947 message.
949 9. When an address is delayed because of a 4xx response to a RCPT command, it
950 is now the combination of sender and recipient that is delayed in
951 subsequent queue runs until its retry time is reached.
953 10. Unary negation and the bitwise logical operators and, or, xor, not, and
954 shift, have been added to the eval: and eval10: expansion items.
956 11. The variables $interface_address and $interface_port have been renamed
957 as $received_ip_address and $received_port, to make it clear that they
958 relate to message reception rather than delivery. (The old names remain
959 available for compatibility.)
961 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
962 to vary the message that is sent when an SMTP command is accepted.
965 Version 4.63
966 ------------
968 1. There is a new Boolean option called filter_prepend_home for the redirect
969 router.
971 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
972 start of receiving a non-SMTP message, before any of the message has been
973 read.
975 3. When an SMTP error message is specified in a "message" modifier in an ACL,
976 or in a :fail: or :defer: message in a redirect router, Exim now checks the
977 start of the message for an SMTP error code.
979 4. There is a new parameter for LDAP lookups called "referrals", which takes
980 one of the settings "follow" (the default) or "nofollow".
982 5. Version 20070721.2 of exipick now included, offering these new options:
983 --reverse
984 After all other sorting options have bee processed, reverse order
985 before displaying messages (-R is synonym).
986 --random
987 Randomize order of matching messages before displaying.
988 --size
989 Instead of displaying the matching messages, display the sum
990 of their sizes.
991 --sort <variable>[,<variable>...]
992 Before displaying matching messages, sort the messages according to
993 each messages value for each variable.
994 --not
995 Negate the value for every test (returns inverse output from the
996 same criteria without --not).
999 Version 4.62
1000 ------------
1002 1. The ${readsocket expansion item now supports Internet domain sockets as well
1003 as Unix domain sockets. If the first argument begins "inet:", it must be of
1004 the form "inet:host:port". The port is mandatory; it may be a number or the
1005 name of a TCP port in /etc/services. The host may be a name, or it may be an
1006 IP address. An ip address may optionally be enclosed in square brackets.
1007 This is best for IPv6 addresses. For example:
1009 ${readsocket{inet:[::1]:1234}{<request data>}...
1011 Only a single host name may be given, but if looking it up yield more than
1012 one IP address, they are each tried in turn until a connection is made. Once
1013 a connection has been made, the behaviour is as for ${readsocket with a Unix
1014 domain socket.
1016 2. If a redirect router sets up file or pipe deliveries for more than one
1017 incoming address, and the relevant transport has batch_max set greater than
1018 one, a batch delivery now occurs.
1020 3. The appendfile transport has a new option called maildirfolder_create_regex.
1021 Its value is a regular expression. For a maildir delivery, this is matched
1022 against the maildir directory; if it matches, Exim ensures that a
1023 maildirfolder file is created alongside the new, cur, and tmp directories.
1026 Version 4.61
1027 ------------
1029 The documentation is up-to-date for the 4.61 release. Major new features since
1030 the 4.60 release are:
1032 . An option called disable_ipv6, to disable the use of IPv6 completely.
1034 . An increase in the number of ACL variables to 20 of each type.
1036 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
1037 $2, $3, (though those are still set) because the numeric variables get used
1038 for other things in complicated expansions.
1040 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
1042 . It is possible to use setclassresources() on some BSD OS to control the
1043 resources used in pipe deliveries.
1045 . A new ACL modifier called add_header, which can be used with any verb.
1047 . More errors are detectable in retry rules.
1049 There are a number of other additions too.
1052 Version 4.60
1053 ------------
1055 The documentation is up-to-date for the 4.60 release. Major new features since
1056 the 4.50 release are:
1058 . Support for SQLite.
1060 . Support for IGNOREQUOTA in LMTP.
1062 . Extensions to the "submission mode" features.
1064 . Support for Client SMTP Authorization (CSA).
1066 . Support for ratelimiting hosts and users.
1068 . New expansion items to help with the BATV "prvs" scheme.
1070 . A "match_ip" condition, that matches an IP address against a list.
1072 There are many more minor changes.
1074 ****