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.
12 1. The ACL conditions regex and mime_regex now capture substrings
13 into numeric variables $regex1 to 9, like the "match" expansion condition.
15 2. New $callout_address variable records the address used for a spam=,
16 malware= or verify= callout.
18 3. Transports now take a "max_parallel" option, to limit concurrency.
20 4. Expansion operators ${ipv6norm:<string>} and ${ipv6denorm:<string>}.
21 The latter expands to a 8-element colon-sep set of hex digits including
22 leading zeroes. A trailing ipv4-style dotted-decimal set is converted
23 to hex. Pure ipv4 addresses are converted to IPv4-mapped IPv6.
24 The former operator strips leading zeroes and collapses the longest
25 set of 0-groups to a double-colon.
31 1. Support for using the system standard CA bundle.
33 2. New expansion items $config_file, $config_dir, containing the file
34 and directory name of the main configuration file. Also $exim_version.
36 3. New "malware=" support for Avast.
38 4. New "spam=" variant option for Rspamd.
40 5. Assorted options on malware= and spam= scanners.
42 6. A commandline option to write a comment into the logfile.
44 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
45 be configured to make connections via socks5 proxies.
47 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for
48 the transmission of UTF-8 envelope addresses.
50 9. If built with EXPERIMENTAL_INTERNATIONAL, an expansion item for a commonly
51 used encoding of Maildir folder names.
53 10. A logging option for slow DNS lookups.
55 11. New ${env {<variable>}} expansion.
57 12. A non-SMTP authenticator using information from TLS client certificates.
59 13. Main option "tls_eccurve" for selecting an Elliptic Curve for TLS.
60 Patch originally by Wolfgang Breyha.
62 14. Main option "dns_trust_aa" for trusting your local nameserver at the
69 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
70 DANE smtp draft to assess a secure chain of trust of the certificate
71 used to establish the TLS connection based on a TLSA record in the
74 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
75 and several new events have been created. The reason is because it has
76 been expanded beyond just firing events during the transport phase. Any
77 existing TPDA transport options will have to be rewritten to use a new
78 $event_name expansion variable in a condition. Refer to the
79 experimental-spec.txt for details and examples.
81 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
82 server certs used for TLS match the result of the MX lookup. It does
83 not use the same mechanism as DANE.
93 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
94 configured to expect an initial header from a proxy that will make the
95 actual external source IP:host be used in exim instead of the IP of the
96 proxy that is connecting to it.
98 2. New verify option header_names_ascii, which will check to make sure
99 there are no non-ASCII characters in header names. Exim itself handles
100 those non-ASCII characters, but downstream apps may not, so Exim can
101 detect and reject if those characters are present.
103 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
104 codepoints with valid ones.
106 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
107 command line and matching a regex against the return data for trigger
108 and a second regex to extract malware_name. The mail spoolfile name can
109 be included in the command line.
111 5. The smtp transport now supports options "tls_verify_hosts" and
112 "tls_try_verify_hosts". If either is set the certificate verification
113 is split from the encryption operation. The default remains that a failed
114 verification cancels the encryption.
116 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
117 lookup can now set a list of servers to use that is different from the
120 7. New command-line option -C for exiqgrep to specify alternate exim.conf
121 file when searching the queue.
123 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
125 9. Support for DNSSEC on outbound connections.
127 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
128 "certextract" to extract fields from them. Hash operators md5 and sha1
129 work over them for generating fingerprints, and a new sha256 operator
132 11. PRDR is now supported dy default.
134 12. OCSP stapling is now supported by default.
136 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
137 Delivery Status Notification messages in MIME format, and negociate
138 DSN features per RFC 3461.
144 1. New command-line option -bI:sieve will list all supported sieve extensions
145 of this Exim build on standard output, one per line.
146 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
147 query this to establish the correct list to include in the protocol's
148 SIEVE capability line.
150 2. If the -n option is combined with the -bP option, then the name of an
151 emitted option is not output, only the value (if visible to you).
152 For instance, "exim -n -bP pid_file_path" should just emit a pathname
153 followed by a newline, and no other text.
155 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
156 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
157 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
158 acceptable for security. (Option accepted but ignored if using OpenSSL).
159 Defaults to 1024, the old value. May be lowered only to 512, or raised as
160 far as you like. Raising this may hinder TLS interoperability with other
161 sites and is not currently recommended. Lowering this will permit you to
162 establish a TLS session which is not as secure as you might like.
164 Unless you really know what you are doing, leave it alone.
166 4. If not built with DISABLE_DNSSEC, Exim now has the main option
167 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
168 to send the DO flag to your recursive resolver. If you have a recursive
169 resolver, which can set the Authenticated Data (AD) flag in results, Exim
170 can now detect this. Exim does not perform validation itself, instead
171 relying upon a trusted path to the resolver.
173 Current status: work-in-progress; $sender_host_dnssec variable added.
175 5. DSCP support for outbound connections: on a transport using the smtp driver,
176 set "dscp = ef", for instance, to cause the connections to have the relevant
177 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
179 Similarly for inbound connections, there is a new control modifier, dscp,
180 so "warn control = dscp/ef" in the connect ACL, or after authentication.
182 Supported values depend upon system libraries. "exim -bI:dscp" to list the
183 ones Exim knows of. You can also set a raw number 0..0x3F.
185 6. The -G command-line flag is no longer ignored; it is now equivalent to an
186 ACL setting "control = suppress_local_fixups". The -L command-line flag
187 is now accepted and forces use of syslog, with the provided tag as the
188 process name. A few other flags used by Sendmail are now accepted and
191 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
192 ACL modifier; works for single-recipient mails which are recieved on and
193 deliverable via SMTP. Using the connection made for a recipient verify,
194 if requested before the verify, or a new one made for the purpose while
195 the inbound connection is still active. The bulk of the mail item is copied
196 direct from the inbound socket to the outbound (as well as the spool file).
197 When the source notifies the end of data, the data acceptance by the destination
198 is negociated before the acceptance is sent to the source. If the destination
199 does not accept the mail item, for example due to content-scanning, the item
200 is not accepted from the source and therefore there is no need to generate
201 a bounce mail. This is of benefit when providing a secondary-MX service.
202 The downside is that delays are under the control of the ultimate destination
205 The Recieved-by: header on items delivered by cutthrough is generated
206 early in reception rather than at the end; this will affect any timestamp
207 included. The log line showing delivery is recorded before that showing
208 reception; it uses a new ">>" tag instead of "=>".
210 To support the feature, verify-callout connections can now use ESMTP and TLS.
211 The usual smtp transport options are honoured, plus a (new, default everything)
212 hosts_verify_avoid_tls.
214 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
215 for specific access to the information for each connection. The old names
216 are present for now but deprecated.
218 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
220 8. New expansion operators ${listnamed:name} to get the content of a named list
221 and ${listcount:string} to count the items in a list.
223 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
224 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
225 modules. For some situations this is desirable, but we expect admin in
226 those situations to know they want the feature. More commonly, it means
227 that GUI user modules get loaded and are broken by the setuid Exim being
228 unable to access files specified in environment variables and passed
229 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
230 unless this new option is set.
232 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
233 so have also added a build option which can be used to build Exim with GnuTLS
234 but without trying to use any kind of PKCS11 support. Uncomment this in the
237 AVOID_GNUTLS_PKCS11=yes
239 10. The "acl = name" condition on an ACL now supports optional arguments.
240 New expansion item "${acl {name}{arg}...}" and expansion condition
241 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
242 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
243 Variable $acl_narg contains the number of arguments. If the ACL sets
244 a "message =" value this becomes the result of the expansion item,
245 or the value of $value for the expansion condition. If the ACL returns
246 accept the expansion condition is true; if reject, false. A defer
247 return results in a forced fail.
249 11. Routers and transports can now have multiple headers_add and headers_remove
250 option lines. The concatenated list is used.
252 12. New ACL modifier "remove_header" can remove headers before message gets
253 handled by routers/transports.
255 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
256 "aaaa" and "a" lookups is done and the full set of results returned.
258 14. New expansion variable $headers_added with content from ACL add_header
259 modifier (but not yet added to messsage).
261 15. New 8bitmime status logging option for received messages. Log field "M8S".
263 16. New authenticated_sender logging option, adding to log field "A".
265 17. New expansion variables $router_name and $transport_name. Useful
266 particularly for debug_print as -bt commandline option does not
267 require privilege whereas -d does.
269 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
270 proposed extension to SMTP from Eric Hall.
272 19. The pipe transport has gained the force_command option, to allow
273 decorating commands from user .forward pipe aliases with prefix
274 wrappers, for instance.
276 20. Callout connections can now AUTH; the same controls as normal delivery
279 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
280 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
281 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
282 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
283 dmarc_status. It adds new control flags dmarc_disable_verify and
284 dmarc_enable_forensic.
286 22. Add expansion variable $authenticated_fail_id, which is the username
287 provided to the authentication method which failed. It is available
288 for use in subsequent ACL processing (typically quit or notquit ACLs).
290 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
293 24. New ${hexquote:..string..} expansion operator converts non-printable
294 characters in the string to \xNN form.
296 25. Experimental TPDA (Transport Post Delivery Action) function added.
297 Patch provided by Axel Rau.
299 26. Experimental Redis lookup added. Patch provided by Warren Baker.
305 1. New authenticator driver, "gsasl". Server-only (at present).
306 This is a SASL interface, licensed under GPL, which can be found at
307 http://www.gnu.org/software/gsasl/.
308 This system does not provide sources of data for authentication, so
309 careful use needs to be made of the conditions in Exim.
311 2. New authenticator driver, "heimdal_gssapi". Server-only.
312 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
313 is no longer honoured for setuid programs by Heimdal. Use the
314 "server_keytab" option to point to the keytab.
316 3. The "pkg-config" system can now be used when building Exim to reference
317 cflags and library information for lookups and authenticators, rather
318 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
319 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
320 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
322 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
323 find the headers and libraries for PCRE.
325 4. New expansion variable $tls_bits.
327 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
328 be joined together with ASCII NUL characters to construct the key to pass
329 into the DBM library. Can be used with gsasl to access sasldb2 files as
332 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
334 Avoid release 1.0.1a if you can. Note that the default value of
335 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
336 increased susceptibility to attack. This may still have interoperability
337 implications for very old clients (see version 4.31 change 37) but
338 administrators can choose to make the trade-off themselves and restore
339 compatibility at the cost of session security.
341 7. Use of the new expansion variable $tls_sni in the main configuration option
342 tls_certificate will cause Exim to re-expand the option, if the client
343 sends the TLS Server Name Indication extension, to permit choosing a
344 different certificate; tls_privatekey will also be re-expanded. You must
345 still set these options to expand to valid files when $tls_sni is not set.
347 The SMTP Transport has gained the option tls_sni, which will set a hostname
348 for outbound TLS sessions, and set $tls_sni too.
350 A new log_selector, +tls_sni, has been added, to log received SNI values
351 for Exim as a server.
353 8. The existing "accept_8bitmime" option now defaults to true. This means
354 that Exim is deliberately not strictly RFC compliant. We're following
355 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
356 Those who disagree, or know that they are talking to mail servers that,
357 even today, are not 8-bit clean, need to turn off this option.
359 9. Exim can now be started with -bw (with an optional timeout, given as
360 -bw<timespec>). With this, stdin at startup is a socket that is
361 already listening for connections. This has a more modern name of
362 "socket activation", but forcing the activated socket to fd 0. We're
363 interested in adding more support for modern variants.
365 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
366 for numbers indicates multiplication by 1024^3.
368 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
369 gnutls_require_mac & gnutls_require_protocols are no longer supported.
370 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
371 string, documentation for which is at:
372 http://www.gnutls.org/manual/html_node/Priority-Strings.html
374 SNI support has been added to Exim's GnuTLS integration too.
376 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
377 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
379 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
380 is now available. If the contents of the file are valid, then Exim will
381 send that back in response to a TLS status request; this is OCSP Stapling.
382 Exim will not maintain the contents of the file in any way: administrators
383 are responsible for ensuring that it is up-to-date.
385 See "experimental-spec.txt" for more details.
387 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
388 identically to TXT record lookups.
390 14. New expansion variable $tod_epoch_l for higher-precision time.
392 15. New global option tls_dh_max_bits, defaulting to current value of NSS
393 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
394 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
396 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
397 Option can now be a path or an identifier for a standard prime.
398 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
399 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
402 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
403 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
404 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
410 1. New options for the ratelimit ACL condition: /count= and /unique=.
411 The /noupdate option has been replaced by a /readonly option.
413 2. The SMTP transport's protocol option may now be set to "smtps", to
414 use SSL-on-connect outbound.
416 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
417 there is a problem talking to the AV scanner, or the AV scanner running.
419 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
420 and check if the search item is a member of the list. This does not
421 support named lists, but does subject the list part to string expansion.
423 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
424 built, Exim no longer performs string expansion on the second string of
425 the match_* expansion conditions: "match_address", "match_domain",
426 "match_ip" & "match_local_part". Named lists can still be used.
432 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
433 or off in the resolver library.
439 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
440 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
441 libraries. The following global options have been added in support of
442 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
443 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
445 2. The pipe transport now takes a boolean option, "freeze_signal", default
446 false. When true, if the external delivery command exits on a signal then
447 Exim will freeze the message in the queue, instead of generating a bounce.
449 3. Log filenames may now use %M as an escape, instead of %D (still available).
450 The %M pattern expands to yyyymm, providing month-level resolution.
452 4. The $message_linecount variable is now updated for the maildir_tag option,
453 in the same way as $message_size, to reflect the real number of lines,
454 including any header additions or removals from transport.
456 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
457 Exim now selects entries randomly, to better scale in a cluster setup.
463 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
464 the flaw permitted the Exim run-time user to cause root to append to
465 arbitrary files of the attacker's choosing, with the content based
466 on content supplied by the attacker.
468 2. Exim now supports loading some lookup types at run-time, using your
469 platform's dlopen() functionality. This has limited platform support
470 and the intention is not to support every variant, it's limited to
471 dlopen(). This permits the main Exim binary to not be linked against
472 all the libraries needed for all the lookup types.
478 NOTE: this version is not guaranteed backwards-compatible, please read the
479 items below carefully
481 1. A new main configuration option, "openssl_options", is available if Exim
482 is built with SSL support provided by OpenSSL. The option allows
483 administrators to specify OpenSSL options to be used on connections;
484 typically this is to set bug compatibility features which the OpenSSL
485 developers have not enabled by default. There may be security
486 consequences for certain options, so these should not be changed
489 2. A new pipe transport option, "permit_coredumps", may help with problem
490 diagnosis in some scenarios. Note that Exim is typically installed as
491 a setuid binary, which on most OSes will inhibit coredumps by default,
492 so that safety mechanism would have to be overridden for this option to
493 be able to take effect.
495 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
496 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
497 Note that this switches Exim to use a new API ("INSTREAM") and a future
498 release of ClamAV will remove support for the old API ("STREAM").
500 The av_scanner option, when set to "clamd", now takes an optional third
501 part, "local", which causes Exim to pass a filename to ClamAV instead of
502 the file content. This is the same behaviour as when clamd is pointed at
503 a Unix-domain socket. For example:
505 av_scanner = clamd:192.0.2.3 1234:local
507 ClamAV's ExtendedDetectionInfo response format is now handled.
509 4. There is now a -bmalware option, restricted to admin users. This option
510 takes one parameter, a filename, and scans that file with Exim's
511 malware-scanning framework. This is intended purely as a debugging aid
512 to ensure that Exim's scanning is working, not to replace other tools.
513 Note that the ACL framework is not invoked, so if av_scanner references
514 ACL variables without a fallback then this will fail.
516 5. There is a new expansion operator, "reverse_ip", which will reverse IP
517 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
519 ${reverse_ip:192.0.2.4}
521 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
522 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
524 6. There is a new ACL control called "debug", to enable debug logging.
525 This allows selective logging of certain incoming transactions within
526 production environments, with some care. It takes two options, "tag"
527 and "opts"; "tag" is included in the filename of the log and "opts"
528 is used as per the -d<options> command-line option. Examples, which
529 don't all make sense in all contexts:
532 control = debug/tag=.$sender_host_address
533 control = debug/opts=+expand+acl
534 control = debug/tag=.$message_exim_id/opts=+expand
536 7. It has always been implicit in the design and the documentation that
537 "the Exim user" is not root. src/EDITME said that using root was
538 "very strongly discouraged". This is not enough to keep people from
539 shooting themselves in the foot in days when many don't configure Exim
540 themselves but via package build managers. The security consequences of
541 running various bits of network code are severe if there should be bugs in
542 them. As such, the Exim user may no longer be root. If configured
543 statically, Exim will refuse to build. If configured as ref:user then Exim
544 will exit shortly after start-up. If you must shoot yourself in the foot,
545 then henceforth you will have to maintain your own local patches to strip
548 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
549 condition logic to determine truth/failure and will fail to expand many
550 strings, bool_lax{} uses the router condition logic, where most strings
552 Note: bool{00} is false, bool_lax{00} is true.
554 9. Routers now support multiple "condition" tests.
556 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
557 Setting this allows an admin to define which entry in the tcpwrappers
558 config file will be used to control access to the daemon. This option
559 is only available when Exim is built with USE_TCP_WRAPPERS. The
560 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
563 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
564 the Exim run-time user, instead of root.
566 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
567 is forced on. This is mitigated by the new build option
568 TRUSTED_CONFIG_LIST which defines a list of configuration files which
569 are trusted; one per line. If a config file is owned by root and matches
570 a pathname in the list, then it may be invoked by the Exim build-time
571 user without Exim relinquishing root privileges.
573 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
574 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
575 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
576 include the main config. As a transition mechanism, we are temporarily
577 providing a work-around: the new build option WHITELIST_D_MACROS provides
578 a colon-separated list of macro names which may be overridden by the Exim
579 run-time user. The values of these macros are constrained to the regex
580 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
586 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
587 writable, the other to locking of MBX folders (not mbox).
589 2. MySQL stored procedures are now supported.
591 3. The dkim_domain transport option is now a list, not a single string, and
592 messages will be signed for each element in the list (discarding
595 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
596 in the presence of multiple character strings within the RR. Prior to 4.70,
597 only the first string would be returned. The dnsdb lookup now, by default,
598 preserves the pre-4.70 semantics, but also now takes an extended output
599 separator specification. The separator can be followed by a semicolon, to
600 concatenate the individual text strings together with no join character,
601 or by a comma and a second separator character, in which case the text
602 strings within a TXT record are joined on that second character.
603 Administrators are reminded that DNS provides no ordering guarantees
604 between multiple records in an RRset. For example:
606 foo.example. IN TXT "a" "b" "c"
607 foo.example. IN TXT "d" "e" "f"
609 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
610 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
611 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
617 1. Native DKIM support without an external library.
618 (Note that if no action to prevent it is taken, a straight upgrade will
619 result in DKIM verification of all signed incoming emails. See spec
620 for details on conditionally disabling)
622 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
624 3. There is now a bool{} expansion condition which maps certain strings to
625 true/false condition values (most likely of use in conjunction with the
626 and{} expansion operator).
628 4. The $spam_score, $spam_bar and $spam_report variables are now available
631 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
632 options, provided that Exim is invoked by an admin_user.
634 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
635 which increases compatibility with older clients at the cost of decreased
636 security. Don't set this unless you need to support such clients.
638 7. There is a new expansion operator, ${randint:...} which will produce a
639 "random" number less than the supplied integer. This randomness is
640 not guaranteed to be cryptographically strong, but depending upon how
641 Exim was built may be better than the most naive schemes.
643 8. Exim now explicitly ensures that SHA256 is available when linked against
646 9. The transport_filter_timeout option now applies to SMTP transports too.
652 1. Preliminary DKIM support in Experimental.
658 1. The body_linecount and body_zerocount C variables are now exported in the
661 2. When a dnslists lookup succeeds, the key that was looked up is now placed
662 in $dnslist_matched. When the key is an IP address, it is not reversed in
663 this variable (though it is, of course, in the actual lookup). In simple
666 deny dnslists = spamhaus.example
668 the key is also available in another variable (in this case,
669 $sender_host_address). In more complicated cases, however, this is not
670 true. For example, using a data lookup might generate a dnslists lookup
673 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
675 If this condition succeeds, the value in $dnslist_matched might be
676 192.168.6.7 (for example).
678 3. Authenticators now have a client_condition option. When Exim is running as
679 a client, it skips an authenticator whose client_condition expansion yields
680 "0", "no", or "false". This can be used, for example, to skip plain text
681 authenticators when the connection is not encrypted by a setting such as:
683 client_condition = ${if !eq{$tls_cipher}{}}
685 Note that the 4.67 documentation states that $tls_cipher contains the
686 cipher used for incoming messages. In fact, during SMTP delivery, it
687 contains the cipher used for the delivery. The same is true for
690 4. There is now a -Mvc <message-id> option, which outputs a copy of the
691 message to the standard output, in RFC 2822 format. The option can be used
692 only by an admin user.
694 5. There is now a /noupdate option for the ratelimit ACL condition. It
695 computes the rate and checks the limit as normal, but it does not update
696 the saved data. This means that, in relevant ACLs, it is possible to lookup
697 the existence of a specified (or auto-generated) ratelimit key without
698 incrementing the ratelimit counter for that key.
700 In order for this to be useful, another ACL entry must set the rate
701 for the same key somewhere (otherwise it will always be zero).
706 # Read the rate; if it doesn't exist or is below the maximum
708 deny ratelimit = 100 / 5m / strict / noupdate
709 log_message = RATE: $sender_rate / $sender_rate_period \
710 (max $sender_rate_limit)
712 [... some other logic and tests...]
714 warn ratelimit = 100 / 5m / strict / per_cmd
715 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
716 (max $sender_rate_limit)
717 condition = ${if le{$sender_rate}{$sender_rate_limit}}
721 6. The variable $max_received_linelength contains the number of bytes in the
722 longest line that was received as part of the message, not counting the
723 line termination character(s).
725 7. Host lists can now include +ignore_defer and +include_defer, analagous to
726 +ignore_unknown and +include_unknown. These options should be used with
727 care, probably only in non-critical host lists such as whitelists.
729 8. There's a new option called queue_only_load_latch, which defaults true.
730 If set false when queue_only_load is greater than zero, Exim re-evaluates
731 the load for each incoming message in an SMTP session. Otherwise, once one
732 message is queued, the remainder are also.
734 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
735 cases when an SMTP session ends without sending QUIT. However, when Exim
736 itself is is bad trouble, such as being unable to write to its log files,
737 this ACL is not run, because it might try to do things (such as write to
738 log files) that make the situation even worse.
740 Like the QUIT ACL, this new ACL is provided to make it possible to gather
741 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
742 modifier is forbidden in this ACL.
744 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
745 to a string that indicates the reason for the termination of the SMTP
746 connection. The possible values are:
748 acl-drop Another ACL issued a "drop" command
749 bad-commands Too many unknown or non-mail commands
750 command-timeout Timeout while reading SMTP commands
751 connection-lost The SMTP connection has been lost
752 data-timeout Timeout while reading message data
753 local-scan-error The local_scan() function crashed
754 local-scan-timeout The local_scan() function timed out
755 signal-exit SIGTERM or SIGINT
756 synchronization-error SMTP synchronization error
757 tls-failed TLS failed to start
759 In most cases when an SMTP connection is closed without having received
760 QUIT, Exim sends an SMTP response message before actually closing the
761 connection. With the exception of acl-drop, the default message can be
762 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
763 "drop" verb in another ACL, it is the message from the other ACL that is
766 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
767 servers with individual queries. This is done by starting the query with
768 "servers=x:y:z;", where each item in the list may take one of two forms:
770 (1) If it is just a host name, the appropriate global option (mysql_servers
771 or pgsql_servers) is searched for a host of the same name, and the
772 remaining parameters (database, user, password) are taken from there.
774 (2) If it contains any slashes, it is taken as a complete parameter set.
776 The list of servers is used in exactly the same was as the global list.
777 Once a connection to a server has happened and a query has been
778 successfully executed, processing of the lookup ceases.
780 This feature is intended for use in master/slave situations where updates
781 are occurring, and one wants to update a master rather than a slave. If the
782 masters are in the list for reading, you might have:
784 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
786 In an updating lookup, you could then write
788 ${lookup mysql{servers=master; UPDATE ...}
790 If, on the other hand, the master is not to be used for reading lookups:
792 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
794 you can still update the master by
796 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
798 11. The message_body_newlines option (default FALSE, for backwards
799 compatibility) can be used to control whether newlines are present in
800 $message_body and $message_body_end. If it is FALSE, they are replaced by
807 1. There is a new log selector called smtp_no_mail, which is not included in
808 the default setting. When it is set, a line is written to the main log
809 whenever an accepted SMTP connection terminates without having issued a
812 2. When an item in a dnslists list is followed by = and & and a list of IP
813 addresses, the behaviour was not clear when the lookup returned more than
814 one IP address. This has been solved by the addition of == and =& for "all"
815 rather than the default "any" matching.
817 3. Up till now, the only control over which cipher suites GnuTLS uses has been
818 for the cipher algorithms. New options have been added to allow some of the
819 other parameters to be varied.
821 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
822 set, Exim compiles a runtime option called disable_fsync.
824 5. There is a new variable called $smtp_count_at_connection_start.
826 6. There's a new control called no_pipelining.
828 7. There are two new variables called $sending_ip_address and $sending_port.
829 These are set whenever an SMTP connection to another host has been set up.
831 8. The expansion of the helo_data option in the smtp transport now happens
832 after the connection to the server has been made.
834 9. There is a new expansion operator ${rfc2047d: that decodes strings that
835 are encoded as per RFC 2047.
837 10. There is a new log selector called "pid", which causes the current process
838 id to be added to every log line, in square brackets, immediately after the
841 11. Exim has been modified so that it flushes SMTP output before implementing
842 a delay in an ACL. It also flushes the output before performing a callout,
843 as this can take a substantial time. These behaviours can be disabled by
844 obeying control = no_delay_flush or control = no_callout_flush,
845 respectively, at some earlier stage of the connection.
847 12. There are two new expansion conditions that iterate over a list. They are
848 called forany and forall.
850 13. There's a new global option called dsn_from that can be used to vary the
851 contents of From: lines in bounces and other automatically generated
852 messages ("delivery status notifications" - hence the name of the option).
854 14. The smtp transport has a new option called hosts_avoid_pipelining.
856 15. By default, exigrep does case-insensitive matches. There is now a -I option
857 that makes it case-sensitive.
859 16. A number of new features ("addresses", "map", "filter", and "reduce") have
860 been added to string expansions to make it easier to process lists of
861 items, typically addresses.
863 17. There's a new ACL modifier called "continue". It does nothing of itself,
864 and processing of the ACL always continues with the next condition or
865 modifier. It is provided so that the side effects of expanding its argument
868 18. It is now possible to use newline and other control characters (those with
869 values less than 32, plus DEL) as separators in lists.
871 19. The exigrep utility now has a -v option, which inverts the matching
874 20. The host_find_failed option in the manualroute router can now be set to
881 No new features were added to 4.66.
887 No new features were added to 4.65.
893 1. ACL variables can now be given arbitrary names, as long as they start with
894 "acl_c" or "acl_m" (for connection variables and message variables), are at
895 least six characters long, with the sixth character being either a digit or
898 2. There is a new ACL modifier called log_reject_target. It makes it possible
899 to specify which logs are used for messages about ACL rejections.
901 3. There is a new authenticator called "dovecot". This is an interface to the
902 authentication facility of the Dovecot POP/IMAP server, which can support a
903 number of authentication methods.
905 4. The variable $message_headers_raw provides a concatenation of all the
906 messages's headers without any decoding. This is in contrast to
907 $message_headers, which does RFC2047 decoding on the header contents.
909 5. In a DNS black list, if two domain names, comma-separated, are given, the
910 second is used first to do an initial check, making use of any IP value
911 restrictions that are set. If there is a match, the first domain is used,
912 without any IP value restrictions, to get the TXT record.
914 6. All authenticators now have a server_condition option.
916 7. There is a new command-line option called -Mset. It is useful only in
917 conjunction with -be (that is, when testing string expansions). It must be
918 followed by a message id; Exim loads the given message from its spool
919 before doing the expansions.
921 8. Another similar new command-line option is called -bem. It operates like
922 -be except that it must be followed by the name of a file that contains a
925 9. When an address is delayed because of a 4xx response to a RCPT command, it
926 is now the combination of sender and recipient that is delayed in
927 subsequent queue runs until its retry time is reached.
929 10. Unary negation and the bitwise logical operators and, or, xor, not, and
930 shift, have been added to the eval: and eval10: expansion items.
932 11. The variables $interface_address and $interface_port have been renamed
933 as $received_ip_address and $received_port, to make it clear that they
934 relate to message reception rather than delivery. (The old names remain
935 available for compatibility.)
937 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
938 to vary the message that is sent when an SMTP command is accepted.
944 1. There is a new Boolean option called filter_prepend_home for the redirect
947 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
948 start of receiving a non-SMTP message, before any of the message has been
951 3. When an SMTP error message is specified in a "message" modifier in an ACL,
952 or in a :fail: or :defer: message in a redirect router, Exim now checks the
953 start of the message for an SMTP error code.
955 4. There is a new parameter for LDAP lookups called "referrals", which takes
956 one of the settings "follow" (the default) or "nofollow".
958 5. Version 20070721.2 of exipick now included, offering these new options:
960 After all other sorting options have bee processed, reverse order
961 before displaying messages (-R is synonym).
963 Randomize order of matching messages before displaying.
965 Instead of displaying the matching messages, display the sum
967 --sort <variable>[,<variable>...]
968 Before displaying matching messages, sort the messages according to
969 each messages value for each variable.
971 Negate the value for every test (returns inverse output from the
972 same criteria without --not).
978 1. The ${readsocket expansion item now supports Internet domain sockets as well
979 as Unix domain sockets. If the first argument begins "inet:", it must be of
980 the form "inet:host:port". The port is mandatory; it may be a number or the
981 name of a TCP port in /etc/services. The host may be a name, or it may be an
982 IP address. An ip address may optionally be enclosed in square brackets.
983 This is best for IPv6 addresses. For example:
985 ${readsocket{inet:[::1]:1234}{<request data>}...
987 Only a single host name may be given, but if looking it up yield more than
988 one IP address, they are each tried in turn until a connection is made. Once
989 a connection has been made, the behaviour is as for ${readsocket with a Unix
992 2. If a redirect router sets up file or pipe deliveries for more than one
993 incoming address, and the relevant transport has batch_max set greater than
994 one, a batch delivery now occurs.
996 3. The appendfile transport has a new option called maildirfolder_create_regex.
997 Its value is a regular expression. For a maildir delivery, this is matched
998 against the maildir directory; if it matches, Exim ensures that a
999 maildirfolder file is created alongside the new, cur, and tmp directories.
1005 The documentation is up-to-date for the 4.61 release. Major new features since
1006 the 4.60 release are:
1008 . An option called disable_ipv6, to disable the use of IPv6 completely.
1010 . An increase in the number of ACL variables to 20 of each type.
1012 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
1013 $2, $3, (though those are still set) because the numeric variables get used
1014 for other things in complicated expansions.
1016 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
1018 . It is possible to use setclassresources() on some BSD OS to control the
1019 resources used in pipe deliveries.
1021 . A new ACL modifier called add_header, which can be used with any verb.
1023 . More errors are detectable in retry rules.
1025 There are a number of other additions too.
1031 The documentation is up-to-date for the 4.60 release. Major new features since
1032 the 4.50 release are:
1034 . Support for SQLite.
1036 . Support for IGNOREQUOTA in LMTP.
1038 . Extensions to the "submission mode" features.
1040 . Support for Client SMTP Authorization (CSA).
1042 . Support for ratelimiting hosts and users.
1044 . New expansion items to help with the BATV "prvs" scheme.
1046 . A "match_ip" condition, that matches an IP address against a list.
1048 There are many more minor changes.
git://git.exim.org / users / heiko / exim.git / blob