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 new perl_taintmode option allows to run the embedded perl
13 interpreter in taint mode.
15 2. New log_selector: dnssec, adds a "DS" tag to acceptance and delivery lines.
17 3. Speculative debugging, via a "kill" option to the "control=debug" ACL
20 4. New expansion item ${sha3:<string>} / ${sha3_<N>:<string>}.
21 N can be 224, 256 (default), 384, 512.
22 With GnuTLS 3.5.0 or later, only.
24 5. Facility for named queues: A commandline argument can specify
25 the queue name for a queue operation, and an ACL modifier can set
26 the queue to be used for a message. A $queue_name variable gives
29 6. New expansion operators base32/base32d.
31 7. The CHUNKING ESMTP extension from RFC 3030. May give some slight
32 performance increase and network load decrease. Main config option
33 chunking_advertise_hosts, and smtp transport option hosts_try_chunking
36 8. LMDB lookup support, as Experimental. Patch supplied by Andrew Colin Kissa.
38 9. Expansion operator escape8bit, like escape but not touching newline etc..
40 10. Feature macros, generated from compile options. All start with "_HAVE_"
41 and go on with some roughly recognisable name. Use the "-bP macros"
42 command-line option to see what is present.
48 1. The ACL conditions regex and mime_regex now capture substrings
49 into numeric variables $regex1 to 9, like the "match" expansion condition.
51 2. New $callout_address variable records the address used for a spam=,
52 malware= or verify= callout.
54 3. Transports now take a "max_parallel" option, to limit concurrency.
56 4. Expansion operators ${ipv6norm:<string>} and ${ipv6denorm:<string>}.
57 The latter expands to a 8-element colon-sep set of hex digits including
58 leading zeroes. A trailing ipv4-style dotted-decimal set is converted
59 to hex. Pure ipv4 addresses are converted to IPv4-mapped IPv6.
60 The former operator strips leading zeroes and collapses the longest
61 set of 0-groups to a double-colon.
63 5. New "-bP config" support, to dump the effective configuration.
65 6. New $dkim_key_length variable.
67 7. New base64d and base64 expansion items (the existing str2b64 being a
68 synonym of the latter). Add support in base64 for certificates.
70 8. New main configuration option "bounce_return_linesize_limit" to
71 avoid oversize bodies in bounces. The dafault value matches RFC
74 9. New $initial_cwd expansion variable.
80 1. Support for using the system standard CA bundle.
82 2. New expansion items $config_file, $config_dir, containing the file
83 and directory name of the main configuration file. Also $exim_version.
85 3. New "malware=" support for Avast.
87 4. New "spam=" variant option for Rspamd.
89 5. Assorted options on malware= and spam= scanners.
91 6. A commandline option to write a comment into the logfile.
93 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
94 be configured to make connections via socks5 proxies.
96 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for
97 the transmission of UTF-8 envelope addresses.
99 9. If built with EXPERIMENTAL_INTERNATIONAL, an expansion item for a commonly
100 used encoding of Maildir folder names.
102 10. A logging option for slow DNS lookups.
104 11. New ${env {<variable>}} expansion.
106 12. A non-SMTP authenticator using information from TLS client certificates.
108 13. Main option "tls_eccurve" for selecting an Elliptic Curve for TLS.
109 Patch originally by Wolfgang Breyha.
111 14. Main option "dns_trust_aa" for trusting your local nameserver at the
112 same level as DNSSEC.
118 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
119 DANE smtp draft to assess a secure chain of trust of the certificate
120 used to establish the TLS connection based on a TLSA record in the
121 domain of the sender.
123 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
124 and several new events have been created. The reason is because it has
125 been expanded beyond just firing events during the transport phase. Any
126 existing TPDA transport options will have to be rewritten to use a new
127 $event_name expansion variable in a condition. Refer to the
128 experimental-spec.txt for details and examples.
130 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
131 server certs used for TLS match the result of the MX lookup. It does
132 not use the same mechanism as DANE.
142 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
143 configured to expect an initial header from a proxy that will make the
144 actual external source IP:host be used in exim instead of the IP of the
145 proxy that is connecting to it.
147 2. New verify option header_names_ascii, which will check to make sure
148 there are no non-ASCII characters in header names. Exim itself handles
149 those non-ASCII characters, but downstream apps may not, so Exim can
150 detect and reject if those characters are present.
152 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
153 codepoints with valid ones.
155 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
156 command line and matching a regex against the return data for trigger
157 and a second regex to extract malware_name. The mail spoolfile name can
158 be included in the command line.
160 5. The smtp transport now supports options "tls_verify_hosts" and
161 "tls_try_verify_hosts". If either is set the certificate verification
162 is split from the encryption operation. The default remains that a failed
163 verification cancels the encryption.
165 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
166 lookup can now set a list of servers to use that is different from the
169 7. New command-line option -C for exiqgrep to specify alternate exim.conf
170 file when searching the queue.
172 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
174 9. Support for DNSSEC on outbound connections.
176 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
177 "certextract" to extract fields from them. Hash operators md5 and sha1
178 work over them for generating fingerprints, and a new sha256 operator
181 11. PRDR is now supported dy default.
183 12. OCSP stapling is now supported by default.
185 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
186 Delivery Status Notification messages in MIME format, and negociate
187 DSN features per RFC 3461.
193 1. New command-line option -bI:sieve will list all supported sieve extensions
194 of this Exim build on standard output, one per line.
195 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
196 query this to establish the correct list to include in the protocol's
197 SIEVE capability line.
199 2. If the -n option is combined with the -bP option, then the name of an
200 emitted option is not output, only the value (if visible to you).
201 For instance, "exim -n -bP pid_file_path" should just emit a pathname
202 followed by a newline, and no other text.
204 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
205 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
206 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
207 acceptable for security. (Option accepted but ignored if using OpenSSL).
208 Defaults to 1024, the old value. May be lowered only to 512, or raised as
209 far as you like. Raising this may hinder TLS interoperability with other
210 sites and is not currently recommended. Lowering this will permit you to
211 establish a TLS session which is not as secure as you might like.
213 Unless you really know what you are doing, leave it alone.
215 4. If not built with DISABLE_DNSSEC, Exim now has the main option
216 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
217 to send the DO flag to your recursive resolver. If you have a recursive
218 resolver, which can set the Authenticated Data (AD) flag in results, Exim
219 can now detect this. Exim does not perform validation itself, instead
220 relying upon a trusted path to the resolver.
222 Current status: work-in-progress; $sender_host_dnssec variable added.
224 5. DSCP support for outbound connections: on a transport using the smtp driver,
225 set "dscp = ef", for instance, to cause the connections to have the relevant
226 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
228 Similarly for inbound connections, there is a new control modifier, dscp,
229 so "warn control = dscp/ef" in the connect ACL, or after authentication.
231 Supported values depend upon system libraries. "exim -bI:dscp" to list the
232 ones Exim knows of. You can also set a raw number 0..0x3F.
234 6. The -G command-line flag is no longer ignored; it is now equivalent to an
235 ACL setting "control = suppress_local_fixups". The -L command-line flag
236 is now accepted and forces use of syslog, with the provided tag as the
237 process name. A few other flags used by Sendmail are now accepted and
240 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
241 ACL modifier; works for single-recipient mails which are recieved on and
242 deliverable via SMTP. Using the connection made for a recipient verify,
243 if requested before the verify, or a new one made for the purpose while
244 the inbound connection is still active. The bulk of the mail item is copied
245 direct from the inbound socket to the outbound (as well as the spool file).
246 When the source notifies the end of data, the data acceptance by the destination
247 is negociated before the acceptance is sent to the source. If the destination
248 does not accept the mail item, for example due to content-scanning, the item
249 is not accepted from the source and therefore there is no need to generate
250 a bounce mail. This is of benefit when providing a secondary-MX service.
251 The downside is that delays are under the control of the ultimate destination
254 The Recieved-by: header on items delivered by cutthrough is generated
255 early in reception rather than at the end; this will affect any timestamp
256 included. The log line showing delivery is recorded before that showing
257 reception; it uses a new ">>" tag instead of "=>".
259 To support the feature, verify-callout connections can now use ESMTP and TLS.
260 The usual smtp transport options are honoured, plus a (new, default everything)
261 hosts_verify_avoid_tls.
263 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
264 for specific access to the information for each connection. The old names
265 are present for now but deprecated.
267 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
269 8. New expansion operators ${listnamed:name} to get the content of a named list
270 and ${listcount:string} to count the items in a list.
272 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
273 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
274 modules. For some situations this is desirable, but we expect admin in
275 those situations to know they want the feature. More commonly, it means
276 that GUI user modules get loaded and are broken by the setuid Exim being
277 unable to access files specified in environment variables and passed
278 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
279 unless this new option is set.
281 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
282 so have also added a build option which can be used to build Exim with GnuTLS
283 but without trying to use any kind of PKCS11 support. Uncomment this in the
286 AVOID_GNUTLS_PKCS11=yes
288 10. The "acl = name" condition on an ACL now supports optional arguments.
289 New expansion item "${acl {name}{arg}...}" and expansion condition
290 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
291 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
292 Variable $acl_narg contains the number of arguments. If the ACL sets
293 a "message =" value this becomes the result of the expansion item,
294 or the value of $value for the expansion condition. If the ACL returns
295 accept the expansion condition is true; if reject, false. A defer
296 return results in a forced fail.
298 11. Routers and transports can now have multiple headers_add and headers_remove
299 option lines. The concatenated list is used.
301 12. New ACL modifier "remove_header" can remove headers before message gets
302 handled by routers/transports.
304 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
305 "aaaa" and "a" lookups is done and the full set of results returned.
307 14. New expansion variable $headers_added with content from ACL add_header
308 modifier (but not yet added to message).
310 15. New 8bitmime status logging option for received messages. Log field "M8S".
312 16. New authenticated_sender logging option, adding to log field "A".
314 17. New expansion variables $router_name and $transport_name. Useful
315 particularly for debug_print as -bt commandline option does not
316 require privilege whereas -d does.
318 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
319 proposed extension to SMTP from Eric Hall.
321 19. The pipe transport has gained the force_command option, to allow
322 decorating commands from user .forward pipe aliases with prefix
323 wrappers, for instance.
325 20. Callout connections can now AUTH; the same controls as normal delivery
328 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
329 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
330 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
331 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
332 dmarc_status. It adds new control flags dmarc_disable_verify and
333 dmarc_enable_forensic.
335 22. Add expansion variable $authenticated_fail_id, which is the username
336 provided to the authentication method which failed. It is available
337 for use in subsequent ACL processing (typically quit or notquit ACLs).
339 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
342 24. New ${hexquote:..string..} expansion operator converts non-printable
343 characters in the string to \xNN form.
345 25. Experimental TPDA (Transport Post Delivery Action) function added.
346 Patch provided by Axel Rau.
348 26. Experimental Redis lookup added. Patch provided by Warren Baker.
354 1. New authenticator driver, "gsasl". Server-only (at present).
355 This is a SASL interface, licensed under GPL, which can be found at
356 http://www.gnu.org/software/gsasl/.
357 This system does not provide sources of data for authentication, so
358 careful use needs to be made of the conditions in Exim.
360 2. New authenticator driver, "heimdal_gssapi". Server-only.
361 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
362 is no longer honoured for setuid programs by Heimdal. Use the
363 "server_keytab" option to point to the keytab.
365 3. The "pkg-config" system can now be used when building Exim to reference
366 cflags and library information for lookups and authenticators, rather
367 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
368 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
369 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
371 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
372 find the headers and libraries for PCRE.
374 4. New expansion variable $tls_bits.
376 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
377 be joined together with ASCII NUL characters to construct the key to pass
378 into the DBM library. Can be used with gsasl to access sasldb2 files as
381 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
383 Avoid release 1.0.1a if you can. Note that the default value of
384 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
385 increased susceptibility to attack. This may still have interoperability
386 implications for very old clients (see version 4.31 change 37) but
387 administrators can choose to make the trade-off themselves and restore
388 compatibility at the cost of session security.
390 7. Use of the new expansion variable $tls_sni in the main configuration option
391 tls_certificate will cause Exim to re-expand the option, if the client
392 sends the TLS Server Name Indication extension, to permit choosing a
393 different certificate; tls_privatekey will also be re-expanded. You must
394 still set these options to expand to valid files when $tls_sni is not set.
396 The SMTP Transport has gained the option tls_sni, which will set a hostname
397 for outbound TLS sessions, and set $tls_sni too.
399 A new log_selector, +tls_sni, has been added, to log received SNI values
400 for Exim as a server.
402 8. The existing "accept_8bitmime" option now defaults to true. This means
403 that Exim is deliberately not strictly RFC compliant. We're following
404 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
405 Those who disagree, or know that they are talking to mail servers that,
406 even today, are not 8-bit clean, need to turn off this option.
408 9. Exim can now be started with -bw (with an optional timeout, given as
409 -bw<timespec>). With this, stdin at startup is a socket that is
410 already listening for connections. This has a more modern name of
411 "socket activation", but forcing the activated socket to fd 0. We're
412 interested in adding more support for modern variants.
414 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
415 for numbers indicates multiplication by 1024^3.
417 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
418 gnutls_require_mac & gnutls_require_protocols are no longer supported.
419 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
420 string, documentation for which is at:
421 http://www.gnutls.org/manual/html_node/Priority-Strings.html
423 SNI support has been added to Exim's GnuTLS integration too.
425 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
426 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
428 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
429 is now available. If the contents of the file are valid, then Exim will
430 send that back in response to a TLS status request; this is OCSP Stapling.
431 Exim will not maintain the contents of the file in any way: administrators
432 are responsible for ensuring that it is up-to-date.
434 See "experimental-spec.txt" for more details.
436 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
437 identically to TXT record lookups.
439 14. New expansion variable $tod_epoch_l for higher-precision time.
441 15. New global option tls_dh_max_bits, defaulting to current value of NSS
442 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
443 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
445 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
446 Option can now be a path or an identifier for a standard prime.
447 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
448 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
451 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
452 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
453 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
459 1. New options for the ratelimit ACL condition: /count= and /unique=.
460 The /noupdate option has been replaced by a /readonly option.
462 2. The SMTP transport's protocol option may now be set to "smtps", to
463 use SSL-on-connect outbound.
465 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
466 there is a problem talking to the AV scanner, or the AV scanner running.
468 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
469 and check if the search item is a member of the list. This does not
470 support named lists, but does subject the list part to string expansion.
472 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
473 built, Exim no longer performs string expansion on the second string of
474 the match_* expansion conditions: "match_address", "match_domain",
475 "match_ip" & "match_local_part". Named lists can still be used.
481 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
482 or off in the resolver library.
488 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
489 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
490 libraries. The following global options have been added in support of
491 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
492 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
494 2. The pipe transport now takes a boolean option, "freeze_signal", default
495 false. When true, if the external delivery command exits on a signal then
496 Exim will freeze the message in the queue, instead of generating a bounce.
498 3. Log filenames may now use %M as an escape, instead of %D (still available).
499 The %M pattern expands to yyyymm, providing month-level resolution.
501 4. The $message_linecount variable is now updated for the maildir_tag option,
502 in the same way as $message_size, to reflect the real number of lines,
503 including any header additions or removals from transport.
505 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
506 Exim now selects entries randomly, to better scale in a cluster setup.
512 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
513 the flaw permitted the Exim run-time user to cause root to append to
514 arbitrary files of the attacker's choosing, with the content based
515 on content supplied by the attacker.
517 2. Exim now supports loading some lookup types at run-time, using your
518 platform's dlopen() functionality. This has limited platform support
519 and the intention is not to support every variant, it's limited to
520 dlopen(). This permits the main Exim binary to not be linked against
521 all the libraries needed for all the lookup types.
527 NOTE: this version is not guaranteed backwards-compatible, please read the
528 items below carefully
530 1. A new main configuration option, "openssl_options", is available if Exim
531 is built with SSL support provided by OpenSSL. The option allows
532 administrators to specify OpenSSL options to be used on connections;
533 typically this is to set bug compatibility features which the OpenSSL
534 developers have not enabled by default. There may be security
535 consequences for certain options, so these should not be changed
538 2. A new pipe transport option, "permit_coredumps", may help with problem
539 diagnosis in some scenarios. Note that Exim is typically installed as
540 a setuid binary, which on most OSes will inhibit coredumps by default,
541 so that safety mechanism would have to be overridden for this option to
542 be able to take effect.
544 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
545 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
546 Note that this switches Exim to use a new API ("INSTREAM") and a future
547 release of ClamAV will remove support for the old API ("STREAM").
549 The av_scanner option, when set to "clamd", now takes an optional third
550 part, "local", which causes Exim to pass a filename to ClamAV instead of
551 the file content. This is the same behaviour as when clamd is pointed at
552 a Unix-domain socket. For example:
554 av_scanner = clamd:192.0.2.3 1234:local
556 ClamAV's ExtendedDetectionInfo response format is now handled.
558 4. There is now a -bmalware option, restricted to admin users. This option
559 takes one parameter, a filename, and scans that file with Exim's
560 malware-scanning framework. This is intended purely as a debugging aid
561 to ensure that Exim's scanning is working, not to replace other tools.
562 Note that the ACL framework is not invoked, so if av_scanner references
563 ACL variables without a fallback then this will fail.
565 5. There is a new expansion operator, "reverse_ip", which will reverse IP
566 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
568 ${reverse_ip:192.0.2.4}
570 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
571 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
573 6. There is a new ACL control called "debug", to enable debug logging.
574 This allows selective logging of certain incoming transactions within
575 production environments, with some care. It takes two options, "tag"
576 and "opts"; "tag" is included in the filename of the log and "opts"
577 is used as per the -d<options> command-line option. Examples, which
578 don't all make sense in all contexts:
581 control = debug/tag=.$sender_host_address
582 control = debug/opts=+expand+acl
583 control = debug/tag=.$message_exim_id/opts=+expand
585 7. It has always been implicit in the design and the documentation that
586 "the Exim user" is not root. src/EDITME said that using root was
587 "very strongly discouraged". This is not enough to keep people from
588 shooting themselves in the foot in days when many don't configure Exim
589 themselves but via package build managers. The security consequences of
590 running various bits of network code are severe if there should be bugs in
591 them. As such, the Exim user may no longer be root. If configured
592 statically, Exim will refuse to build. If configured as ref:user then Exim
593 will exit shortly after start-up. If you must shoot yourself in the foot,
594 then henceforth you will have to maintain your own local patches to strip
597 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
598 condition logic to determine truth/failure and will fail to expand many
599 strings, bool_lax{} uses the router condition logic, where most strings
601 Note: bool{00} is false, bool_lax{00} is true.
603 9. Routers now support multiple "condition" tests.
605 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
606 Setting this allows an admin to define which entry in the tcpwrappers
607 config file will be used to control access to the daemon. This option
608 is only available when Exim is built with USE_TCP_WRAPPERS. The
609 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
612 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
613 the Exim run-time user, instead of root.
615 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
616 is forced on. This is mitigated by the new build option
617 TRUSTED_CONFIG_LIST which defines a list of configuration files which
618 are trusted; one per line. If a config file is owned by root and matches
619 a pathname in the list, then it may be invoked by the Exim build-time
620 user without Exim relinquishing root privileges.
622 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
623 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
624 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
625 include the main config. As a transition mechanism, we are temporarily
626 providing a work-around: the new build option WHITELIST_D_MACROS provides
627 a colon-separated list of macro names which may be overridden by the Exim
628 run-time user. The values of these macros are constrained to the regex
629 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
635 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
636 writable, the other to locking of MBX folders (not mbox).
638 2. MySQL stored procedures are now supported.
640 3. The dkim_domain transport option is now a list, not a single string, and
641 messages will be signed for each element in the list (discarding
644 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
645 in the presence of multiple character strings within the RR. Prior to 4.70,
646 only the first string would be returned. The dnsdb lookup now, by default,
647 preserves the pre-4.70 semantics, but also now takes an extended output
648 separator specification. The separator can be followed by a semicolon, to
649 concatenate the individual text strings together with no join character,
650 or by a comma and a second separator character, in which case the text
651 strings within a TXT record are joined on that second character.
652 Administrators are reminded that DNS provides no ordering guarantees
653 between multiple records in an RRset. For example:
655 foo.example. IN TXT "a" "b" "c"
656 foo.example. IN TXT "d" "e" "f"
658 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
659 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
660 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
666 1. Native DKIM support without an external library.
667 (Note that if no action to prevent it is taken, a straight upgrade will
668 result in DKIM verification of all signed incoming emails. See spec
669 for details on conditionally disabling)
671 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
673 3. There is now a bool{} expansion condition which maps certain strings to
674 true/false condition values (most likely of use in conjunction with the
675 and{} expansion operator).
677 4. The $spam_score, $spam_bar and $spam_report variables are now available
680 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
681 options, provided that Exim is invoked by an admin_user.
683 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
684 which increases compatibility with older clients at the cost of decreased
685 security. Don't set this unless you need to support such clients.
687 7. There is a new expansion operator, ${randint:...} which will produce a
688 "random" number less than the supplied integer. This randomness is
689 not guaranteed to be cryptographically strong, but depending upon how
690 Exim was built may be better than the most naive schemes.
692 8. Exim now explicitly ensures that SHA256 is available when linked against
695 9. The transport_filter_timeout option now applies to SMTP transports too.
701 1. Preliminary DKIM support in Experimental.
707 1. The body_linecount and body_zerocount C variables are now exported in the
710 2. When a dnslists lookup succeeds, the key that was looked up is now placed
711 in $dnslist_matched. When the key is an IP address, it is not reversed in
712 this variable (though it is, of course, in the actual lookup). In simple
715 deny dnslists = spamhaus.example
717 the key is also available in another variable (in this case,
718 $sender_host_address). In more complicated cases, however, this is not
719 true. For example, using a data lookup might generate a dnslists lookup
722 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
724 If this condition succeeds, the value in $dnslist_matched might be
725 192.168.6.7 (for example).
727 3. Authenticators now have a client_condition option. When Exim is running as
728 a client, it skips an authenticator whose client_condition expansion yields
729 "0", "no", or "false". This can be used, for example, to skip plain text
730 authenticators when the connection is not encrypted by a setting such as:
732 client_condition = ${if !eq{$tls_cipher}{}}
734 Note that the 4.67 documentation states that $tls_cipher contains the
735 cipher used for incoming messages. In fact, during SMTP delivery, it
736 contains the cipher used for the delivery. The same is true for
739 4. There is now a -Mvc <message-id> option, which outputs a copy of the
740 message to the standard output, in RFC 2822 format. The option can be used
741 only by an admin user.
743 5. There is now a /noupdate option for the ratelimit ACL condition. It
744 computes the rate and checks the limit as normal, but it does not update
745 the saved data. This means that, in relevant ACLs, it is possible to lookup
746 the existence of a specified (or auto-generated) ratelimit key without
747 incrementing the ratelimit counter for that key.
749 In order for this to be useful, another ACL entry must set the rate
750 for the same key somewhere (otherwise it will always be zero).
755 # Read the rate; if it doesn't exist or is below the maximum
757 deny ratelimit = 100 / 5m / strict / noupdate
758 log_message = RATE: $sender_rate / $sender_rate_period \
759 (max $sender_rate_limit)
761 [... some other logic and tests...]
763 warn ratelimit = 100 / 5m / strict / per_cmd
764 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
765 (max $sender_rate_limit)
766 condition = ${if le{$sender_rate}{$sender_rate_limit}}
770 6. The variable $max_received_linelength contains the number of bytes in the
771 longest line that was received as part of the message, not counting the
772 line termination character(s).
774 7. Host lists can now include +ignore_defer and +include_defer, analagous to
775 +ignore_unknown and +include_unknown. These options should be used with
776 care, probably only in non-critical host lists such as whitelists.
778 8. There's a new option called queue_only_load_latch, which defaults true.
779 If set false when queue_only_load is greater than zero, Exim re-evaluates
780 the load for each incoming message in an SMTP session. Otherwise, once one
781 message is queued, the remainder are also.
783 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
784 cases when an SMTP session ends without sending QUIT. However, when Exim
785 itself is is bad trouble, such as being unable to write to its log files,
786 this ACL is not run, because it might try to do things (such as write to
787 log files) that make the situation even worse.
789 Like the QUIT ACL, this new ACL is provided to make it possible to gather
790 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
791 modifier is forbidden in this ACL.
793 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
794 to a string that indicates the reason for the termination of the SMTP
795 connection. The possible values are:
797 acl-drop Another ACL issued a "drop" command
798 bad-commands Too many unknown or non-mail commands
799 command-timeout Timeout while reading SMTP commands
800 connection-lost The SMTP connection has been lost
801 data-timeout Timeout while reading message data
802 local-scan-error The local_scan() function crashed
803 local-scan-timeout The local_scan() function timed out
804 signal-exit SIGTERM or SIGINT
805 synchronization-error SMTP synchronization error
806 tls-failed TLS failed to start
808 In most cases when an SMTP connection is closed without having received
809 QUIT, Exim sends an SMTP response message before actually closing the
810 connection. With the exception of acl-drop, the default message can be
811 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
812 "drop" verb in another ACL, it is the message from the other ACL that is
815 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
816 servers with individual queries. This is done by starting the query with
817 "servers=x:y:z;", where each item in the list may take one of two forms:
819 (1) If it is just a host name, the appropriate global option (mysql_servers
820 or pgsql_servers) is searched for a host of the same name, and the
821 remaining parameters (database, user, password) are taken from there.
823 (2) If it contains any slashes, it is taken as a complete parameter set.
825 The list of servers is used in exactly the same was as the global list.
826 Once a connection to a server has happened and a query has been
827 successfully executed, processing of the lookup ceases.
829 This feature is intended for use in master/slave situations where updates
830 are occurring, and one wants to update a master rather than a slave. If the
831 masters are in the list for reading, you might have:
833 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
835 In an updating lookup, you could then write
837 ${lookup mysql{servers=master; UPDATE ...}
839 If, on the other hand, the master is not to be used for reading lookups:
841 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
843 you can still update the master by
845 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
847 11. The message_body_newlines option (default FALSE, for backwards
848 compatibility) can be used to control whether newlines are present in
849 $message_body and $message_body_end. If it is FALSE, they are replaced by
856 1. There is a new log selector called smtp_no_mail, which is not included in
857 the default setting. When it is set, a line is written to the main log
858 whenever an accepted SMTP connection terminates without having issued a
861 2. When an item in a dnslists list is followed by = and & and a list of IP
862 addresses, the behaviour was not clear when the lookup returned more than
863 one IP address. This has been solved by the addition of == and =& for "all"
864 rather than the default "any" matching.
866 3. Up till now, the only control over which cipher suites GnuTLS uses has been
867 for the cipher algorithms. New options have been added to allow some of the
868 other parameters to be varied.
870 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
871 set, Exim compiles a runtime option called disable_fsync.
873 5. There is a new variable called $smtp_count_at_connection_start.
875 6. There's a new control called no_pipelining.
877 7. There are two new variables called $sending_ip_address and $sending_port.
878 These are set whenever an SMTP connection to another host has been set up.
880 8. The expansion of the helo_data option in the smtp transport now happens
881 after the connection to the server has been made.
883 9. There is a new expansion operator ${rfc2047d: that decodes strings that
884 are encoded as per RFC 2047.
886 10. There is a new log selector called "pid", which causes the current process
887 id to be added to every log line, in square brackets, immediately after the
890 11. Exim has been modified so that it flushes SMTP output before implementing
891 a delay in an ACL. It also flushes the output before performing a callout,
892 as this can take a substantial time. These behaviours can be disabled by
893 obeying control = no_delay_flush or control = no_callout_flush,
894 respectively, at some earlier stage of the connection.
896 12. There are two new expansion conditions that iterate over a list. They are
897 called forany and forall.
899 13. There's a new global option called dsn_from that can be used to vary the
900 contents of From: lines in bounces and other automatically generated
901 messages ("delivery status notifications" - hence the name of the option).
903 14. The smtp transport has a new option called hosts_avoid_pipelining.
905 15. By default, exigrep does case-insensitive matches. There is now a -I option
906 that makes it case-sensitive.
908 16. A number of new features ("addresses", "map", "filter", and "reduce") have
909 been added to string expansions to make it easier to process lists of
910 items, typically addresses.
912 17. There's a new ACL modifier called "continue". It does nothing of itself,
913 and processing of the ACL always continues with the next condition or
914 modifier. It is provided so that the side effects of expanding its argument
917 18. It is now possible to use newline and other control characters (those with
918 values less than 32, plus DEL) as separators in lists.
920 19. The exigrep utility now has a -v option, which inverts the matching
923 20. The host_find_failed option in the manualroute router can now be set to
930 No new features were added to 4.66.
936 No new features were added to 4.65.
942 1. ACL variables can now be given arbitrary names, as long as they start with
943 "acl_c" or "acl_m" (for connection variables and message variables), are at
944 least six characters long, with the sixth character being either a digit or
947 2. There is a new ACL modifier called log_reject_target. It makes it possible
948 to specify which logs are used for messages about ACL rejections.
950 3. There is a new authenticator called "dovecot". This is an interface to the
951 authentication facility of the Dovecot POP/IMAP server, which can support a
952 number of authentication methods.
954 4. The variable $message_headers_raw provides a concatenation of all the
955 messages's headers without any decoding. This is in contrast to
956 $message_headers, which does RFC2047 decoding on the header contents.
958 5. In a DNS black list, if two domain names, comma-separated, are given, the
959 second is used first to do an initial check, making use of any IP value
960 restrictions that are set. If there is a match, the first domain is used,
961 without any IP value restrictions, to get the TXT record.
963 6. All authenticators now have a server_condition option.
965 7. There is a new command-line option called -Mset. It is useful only in
966 conjunction with -be (that is, when testing string expansions). It must be
967 followed by a message id; Exim loads the given message from its spool
968 before doing the expansions.
970 8. Another similar new command-line option is called -bem. It operates like
971 -be except that it must be followed by the name of a file that contains a
974 9. When an address is delayed because of a 4xx response to a RCPT command, it
975 is now the combination of sender and recipient that is delayed in
976 subsequent queue runs until its retry time is reached.
978 10. Unary negation and the bitwise logical operators and, or, xor, not, and
979 shift, have been added to the eval: and eval10: expansion items.
981 11. The variables $interface_address and $interface_port have been renamed
982 as $received_ip_address and $received_port, to make it clear that they
983 relate to message reception rather than delivery. (The old names remain
984 available for compatibility.)
986 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
987 to vary the message that is sent when an SMTP command is accepted.
993 1. There is a new Boolean option called filter_prepend_home for the redirect
996 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
997 start of receiving a non-SMTP message, before any of the message has been
1000 3. When an SMTP error message is specified in a "message" modifier in an ACL,
1001 or in a :fail: or :defer: message in a redirect router, Exim now checks the
1002 start of the message for an SMTP error code.
1004 4. There is a new parameter for LDAP lookups called "referrals", which takes
1005 one of the settings "follow" (the default) or "nofollow".
1007 5. Version 20070721.2 of exipick now included, offering these new options:
1009 After all other sorting options have bee processed, reverse order
1010 before displaying messages (-R is synonym).
1012 Randomize order of matching messages before displaying.
1014 Instead of displaying the matching messages, display the sum
1016 --sort <variable>[,<variable>...]
1017 Before displaying matching messages, sort the messages according to
1018 each messages value for each variable.
1020 Negate the value for every test (returns inverse output from the
1021 same criteria without --not).
1027 1. The ${readsocket expansion item now supports Internet domain sockets as well
1028 as Unix domain sockets. If the first argument begins "inet:", it must be of
1029 the form "inet:host:port". The port is mandatory; it may be a number or the
1030 name of a TCP port in /etc/services. The host may be a name, or it may be an
1031 IP address. An ip address may optionally be enclosed in square brackets.
1032 This is best for IPv6 addresses. For example:
1034 ${readsocket{inet:[::1]:1234}{<request data>}...
1036 Only a single host name may be given, but if looking it up yield more than
1037 one IP address, they are each tried in turn until a connection is made. Once
1038 a connection has been made, the behaviour is as for ${readsocket with a Unix
1041 2. If a redirect router sets up file or pipe deliveries for more than one
1042 incoming address, and the relevant transport has batch_max set greater than
1043 one, a batch delivery now occurs.
1045 3. The appendfile transport has a new option called maildirfolder_create_regex.
1046 Its value is a regular expression. For a maildir delivery, this is matched
1047 against the maildir directory; if it matches, Exim ensures that a
1048 maildirfolder file is created alongside the new, cur, and tmp directories.
1054 The documentation is up-to-date for the 4.61 release. Major new features since
1055 the 4.60 release are:
1057 . An option called disable_ipv6, to disable the use of IPv6 completely.
1059 . An increase in the number of ACL variables to 20 of each type.
1061 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
1062 $2, $3, (though those are still set) because the numeric variables get used
1063 for other things in complicated expansions.
1065 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
1067 . It is possible to use setclassresources() on some BSD OS to control the
1068 resources used in pipe deliveries.
1070 . A new ACL modifier called add_header, which can be used with any verb.
1072 . More errors are detectable in retry rules.
1074 There are a number of other additions too.
1080 The documentation is up-to-date for the 4.60 release. Major new features since
1081 the 4.50 release are:
1083 . Support for SQLite.
1085 . Support for IGNOREQUOTA in LMTP.
1087 . Extensions to the "submission mode" features.
1089 . Support for Client SMTP Authorization (CSA).
1091 . Support for ratelimiting hosts and users.
1093 . New expansion items to help with the BATV "prvs" scheme.
1095 . A "match_ip" condition, that matches an IP address against a list.
1097 There are many more minor changes.
git://git.exim.org / exim.git / blob