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.
42 1. The ACL conditions regex and mime_regex now capture substrings
43 into numeric variables $regex1 to 9, like the "match" expansion condition.
45 2. New $callout_address variable records the address used for a spam=,
46 malware= or verify= callout.
48 3. Transports now take a "max_parallel" option, to limit concurrency.
50 4. Expansion operators ${ipv6norm:<string>} and ${ipv6denorm:<string>}.
51 The latter expands to a 8-element colon-sep set of hex digits including
52 leading zeroes. A trailing ipv4-style dotted-decimal set is converted
53 to hex. Pure ipv4 addresses are converted to IPv4-mapped IPv6.
54 The former operator strips leading zeroes and collapses the longest
55 set of 0-groups to a double-colon.
57 5. New "-bP config" support, to dump the effective configuration.
59 6. New $dkim_key_length variable.
61 7. New base64d and base64 expansion items (the existing str2b64 being a
62 synonym of the latter). Add support in base64 for certificates.
64 8. New main configuration option "bounce_return_linesize_limit" to
65 avoid oversize bodies in bounces. The dafault value matches RFC
68 9. New $initial_cwd expansion variable.
74 1. Support for using the system standard CA bundle.
76 2. New expansion items $config_file, $config_dir, containing the file
77 and directory name of the main configuration file. Also $exim_version.
79 3. New "malware=" support for Avast.
81 4. New "spam=" variant option for Rspamd.
83 5. Assorted options on malware= and spam= scanners.
85 6. A commandline option to write a comment into the logfile.
87 7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
88 be configured to make connections via socks5 proxies.
90 8. If built with EXPERIMENTAL_INTERNATIONAL, support is included for
91 the transmission of UTF-8 envelope addresses.
93 9. If built with EXPERIMENTAL_INTERNATIONAL, an expansion item for a commonly
94 used encoding of Maildir folder names.
96 10. A logging option for slow DNS lookups.
98 11. New ${env {<variable>}} expansion.
100 12. A non-SMTP authenticator using information from TLS client certificates.
102 13. Main option "tls_eccurve" for selecting an Elliptic Curve for TLS.
103 Patch originally by Wolfgang Breyha.
105 14. Main option "dns_trust_aa" for trusting your local nameserver at the
106 same level as DNSSEC.
112 1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
113 DANE smtp draft to assess a secure chain of trust of the certificate
114 used to establish the TLS connection based on a TLSA record in the
115 domain of the sender.
117 2. The EXPERIMENTAL_TPDA feature has been renamed to EXPERIMENTAL_EVENT
118 and several new events have been created. The reason is because it has
119 been expanded beyond just firing events during the transport phase. Any
120 existing TPDA transport options will have to be rewritten to use a new
121 $event_name expansion variable in a condition. Refer to the
122 experimental-spec.txt for details and examples.
124 3. The EXPERIMENTAL_CERTNAMES features is an enhancement to verify that
125 server certs used for TLS match the result of the MX lookup. It does
126 not use the same mechanism as DANE.
136 1. If built with the EXPERIMENTAL_PROXY feature enabled, Exim can be
137 configured to expect an initial header from a proxy that will make the
138 actual external source IP:host be used in exim instead of the IP of the
139 proxy that is connecting to it.
141 2. New verify option header_names_ascii, which will check to make sure
142 there are no non-ASCII characters in header names. Exim itself handles
143 those non-ASCII characters, but downstream apps may not, so Exim can
144 detect and reject if those characters are present.
146 3. New expansion operator ${utf8clean:string} to replace malformed UTF8
147 codepoints with valid ones.
149 4. New malware type "sock". Talks over a Unix or TCP socket, sending one
150 command line and matching a regex against the return data for trigger
151 and a second regex to extract malware_name. The mail spoolfile name can
152 be included in the command line.
154 5. The smtp transport now supports options "tls_verify_hosts" and
155 "tls_try_verify_hosts". If either is set the certificate verification
156 is split from the encryption operation. The default remains that a failed
157 verification cancels the encryption.
159 6. New SERVERS override of default ldap server list. In the ACLs, an ldap
160 lookup can now set a list of servers to use that is different from the
163 7. New command-line option -C for exiqgrep to specify alternate exim.conf
164 file when searching the queue.
166 8. OCSP now supports GnuTLS also, if you have version 3.1.3 or later of that.
168 9. Support for DNSSEC on outbound connections.
170 10. New variables "tls_(in,out)_(our,peer)cert" and expansion item
171 "certextract" to extract fields from them. Hash operators md5 and sha1
172 work over them for generating fingerprints, and a new sha256 operator
175 11. PRDR is now supported dy default.
177 12. OCSP stapling is now supported by default.
179 13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
180 Delivery Status Notification messages in MIME format, and negociate
181 DSN features per RFC 3461.
187 1. New command-line option -bI:sieve will list all supported sieve extensions
188 of this Exim build on standard output, one per line.
189 ManageSieve (RFC 5804) providers managing scripts for use by Exim should
190 query this to establish the correct list to include in the protocol's
191 SIEVE capability line.
193 2. If the -n option is combined with the -bP option, then the name of an
194 emitted option is not output, only the value (if visible to you).
195 For instance, "exim -n -bP pid_file_path" should just emit a pathname
196 followed by a newline, and no other text.
198 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
199 has a "tls_dh_min_bits" option, to set the minimum acceptable number of
200 bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
201 acceptable for security. (Option accepted but ignored if using OpenSSL).
202 Defaults to 1024, the old value. May be lowered only to 512, or raised as
203 far as you like. Raising this may hinder TLS interoperability with other
204 sites and is not currently recommended. Lowering this will permit you to
205 establish a TLS session which is not as secure as you might like.
207 Unless you really know what you are doing, leave it alone.
209 4. If not built with DISABLE_DNSSEC, Exim now has the main option
210 dns_dnssec_ok; if set to 1 then Exim will initialise the resolver library
211 to send the DO flag to your recursive resolver. If you have a recursive
212 resolver, which can set the Authenticated Data (AD) flag in results, Exim
213 can now detect this. Exim does not perform validation itself, instead
214 relying upon a trusted path to the resolver.
216 Current status: work-in-progress; $sender_host_dnssec variable added.
218 5. DSCP support for outbound connections: on a transport using the smtp driver,
219 set "dscp = ef", for instance, to cause the connections to have the relevant
220 DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
222 Similarly for inbound connections, there is a new control modifier, dscp,
223 so "warn control = dscp/ef" in the connect ACL, or after authentication.
225 Supported values depend upon system libraries. "exim -bI:dscp" to list the
226 ones Exim knows of. You can also set a raw number 0..0x3F.
228 6. The -G command-line flag is no longer ignored; it is now equivalent to an
229 ACL setting "control = suppress_local_fixups". The -L command-line flag
230 is now accepted and forces use of syslog, with the provided tag as the
231 process name. A few other flags used by Sendmail are now accepted and
234 7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
235 ACL modifier; works for single-recipient mails which are recieved on and
236 deliverable via SMTP. Using the connection made for a recipient verify,
237 if requested before the verify, or a new one made for the purpose while
238 the inbound connection is still active. The bulk of the mail item is copied
239 direct from the inbound socket to the outbound (as well as the spool file).
240 When the source notifies the end of data, the data acceptance by the destination
241 is negociated before the acceptance is sent to the source. If the destination
242 does not accept the mail item, for example due to content-scanning, the item
243 is not accepted from the source and therefore there is no need to generate
244 a bounce mail. This is of benefit when providing a secondary-MX service.
245 The downside is that delays are under the control of the ultimate destination
248 The Recieved-by: header on items delivered by cutthrough is generated
249 early in reception rather than at the end; this will affect any timestamp
250 included. The log line showing delivery is recorded before that showing
251 reception; it uses a new ">>" tag instead of "=>".
253 To support the feature, verify-callout connections can now use ESMTP and TLS.
254 The usual smtp transport options are honoured, plus a (new, default everything)
255 hosts_verify_avoid_tls.
257 New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
258 for specific access to the information for each connection. The old names
259 are present for now but deprecated.
261 Not yet supported: IGNOREQUOTA, SIZE, PIPELINING.
263 8. New expansion operators ${listnamed:name} to get the content of a named list
264 and ${listcount:string} to count the items in a list.
266 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
267 rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
268 modules. For some situations this is desirable, but we expect admin in
269 those situations to know they want the feature. More commonly, it means
270 that GUI user modules get loaded and are broken by the setuid Exim being
271 unable to access files specified in environment variables and passed
272 through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
273 unless this new option is set.
275 Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
276 so have also added a build option which can be used to build Exim with GnuTLS
277 but without trying to use any kind of PKCS11 support. Uncomment this in the
280 AVOID_GNUTLS_PKCS11=yes
282 10. The "acl = name" condition on an ACL now supports optional arguments.
283 New expansion item "${acl {name}{arg}...}" and expansion condition
284 "acl {{name}{arg}...}" are added. In all cases up to nine arguments
285 can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
286 Variable $acl_narg contains the number of arguments. If the ACL sets
287 a "message =" value this becomes the result of the expansion item,
288 or the value of $value for the expansion condition. If the ACL returns
289 accept the expansion condition is true; if reject, false. A defer
290 return results in a forced fail.
292 11. Routers and transports can now have multiple headers_add and headers_remove
293 option lines. The concatenated list is used.
295 12. New ACL modifier "remove_header" can remove headers before message gets
296 handled by routers/transports.
298 13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
299 "aaaa" and "a" lookups is done and the full set of results returned.
301 14. New expansion variable $headers_added with content from ACL add_header
302 modifier (but not yet added to message).
304 15. New 8bitmime status logging option for received messages. Log field "M8S".
306 16. New authenticated_sender logging option, adding to log field "A".
308 17. New expansion variables $router_name and $transport_name. Useful
309 particularly for debug_print as -bt commandline option does not
310 require privilege whereas -d does.
312 18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
313 proposed extension to SMTP from Eric Hall.
315 19. The pipe transport has gained the force_command option, to allow
316 decorating commands from user .forward pipe aliases with prefix
317 wrappers, for instance.
319 20. Callout connections can now AUTH; the same controls as normal delivery
322 21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
323 options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
324 It adds new expansion variables $dmarc_ar_header, $dmarc_status,
325 $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
326 dmarc_status. It adds new control flags dmarc_disable_verify and
327 dmarc_enable_forensic.
329 22. Add expansion variable $authenticated_fail_id, which is the username
330 provided to the authentication method which failed. It is available
331 for use in subsequent ACL processing (typically quit or notquit ACLs).
333 23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
336 24. New ${hexquote:..string..} expansion operator converts non-printable
337 characters in the string to \xNN form.
339 25. Experimental TPDA (Transport Post Delivery Action) function added.
340 Patch provided by Axel Rau.
342 26. Experimental Redis lookup added. Patch provided by Warren Baker.
348 1. New authenticator driver, "gsasl". Server-only (at present).
349 This is a SASL interface, licensed under GPL, which can be found at
350 http://www.gnu.org/software/gsasl/.
351 This system does not provide sources of data for authentication, so
352 careful use needs to be made of the conditions in Exim.
354 2. New authenticator driver, "heimdal_gssapi". Server-only.
355 A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
356 is no longer honoured for setuid programs by Heimdal. Use the
357 "server_keytab" option to point to the keytab.
359 3. The "pkg-config" system can now be used when building Exim to reference
360 cflags and library information for lookups and authenticators, rather
361 than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
362 "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
363 without adjusting "TLS_INCLUDE" and "TLS_LIBS".
365 In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
366 find the headers and libraries for PCRE.
368 4. New expansion variable $tls_bits.
370 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
371 be joined together with ASCII NUL characters to construct the key to pass
372 into the DBM library. Can be used with gsasl to access sasldb2 files as
375 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
377 Avoid release 1.0.1a if you can. Note that the default value of
378 "openssl_options" is no longer "+dont_insert_empty_fragments", as that
379 increased susceptibility to attack. This may still have interoperability
380 implications for very old clients (see version 4.31 change 37) but
381 administrators can choose to make the trade-off themselves and restore
382 compatibility at the cost of session security.
384 7. Use of the new expansion variable $tls_sni in the main configuration option
385 tls_certificate will cause Exim to re-expand the option, if the client
386 sends the TLS Server Name Indication extension, to permit choosing a
387 different certificate; tls_privatekey will also be re-expanded. You must
388 still set these options to expand to valid files when $tls_sni is not set.
390 The SMTP Transport has gained the option tls_sni, which will set a hostname
391 for outbound TLS sessions, and set $tls_sni too.
393 A new log_selector, +tls_sni, has been added, to log received SNI values
394 for Exim as a server.
396 8. The existing "accept_8bitmime" option now defaults to true. This means
397 that Exim is deliberately not strictly RFC compliant. We're following
398 Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
399 Those who disagree, or know that they are talking to mail servers that,
400 even today, are not 8-bit clean, need to turn off this option.
402 9. Exim can now be started with -bw (with an optional timeout, given as
403 -bw<timespec>). With this, stdin at startup is a socket that is
404 already listening for connections. This has a more modern name of
405 "socket activation", but forcing the activated socket to fd 0. We're
406 interested in adding more support for modern variants.
408 10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
409 for numbers indicates multiplication by 1024^3.
411 11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
412 gnutls_require_mac & gnutls_require_protocols are no longer supported.
413 tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
414 string, documentation for which is at:
415 http://www.gnutls.org/manual/html_node/Priority-Strings.html
417 SNI support has been added to Exim's GnuTLS integration too.
419 For sufficiently recent GnuTLS libraries, ${randint:..} will now use
420 gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
422 12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
423 is now available. If the contents of the file are valid, then Exim will
424 send that back in response to a TLS status request; this is OCSP Stapling.
425 Exim will not maintain the contents of the file in any way: administrators
426 are responsible for ensuring that it is up-to-date.
428 See "experimental-spec.txt" for more details.
430 13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
431 identically to TXT record lookups.
433 14. New expansion variable $tod_epoch_l for higher-precision time.
435 15. New global option tls_dh_max_bits, defaulting to current value of NSS
436 hard-coded limit of DH ephemeral bits, to fix interop problems caused by
437 GnuTLS 2.12 library recommending a bit count higher than NSS supports.
439 16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
440 Option can now be a path or an identifier for a standard prime.
441 If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
442 Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
445 17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
446 Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
447 install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
453 1. New options for the ratelimit ACL condition: /count= and /unique=.
454 The /noupdate option has been replaced by a /readonly option.
456 2. The SMTP transport's protocol option may now be set to "smtps", to
457 use SSL-on-connect outbound.
459 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
460 there is a problem talking to the AV scanner, or the AV scanner running.
462 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
463 and check if the search item is a member of the list. This does not
464 support named lists, but does subject the list part to string expansion.
466 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
467 built, Exim no longer performs string expansion on the second string of
468 the match_* expansion conditions: "match_address", "match_domain",
469 "match_ip" & "match_local_part". Named lists can still be used.
475 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
476 or off in the resolver library.
482 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
483 is now LDAP/TLS support, given sufficiently modern OpenLDAP client
484 libraries. The following global options have been added in support of
485 this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
486 ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
488 2. The pipe transport now takes a boolean option, "freeze_signal", default
489 false. When true, if the external delivery command exits on a signal then
490 Exim will freeze the message in the queue, instead of generating a bounce.
492 3. Log filenames may now use %M as an escape, instead of %D (still available).
493 The %M pattern expands to yyyymm, providing month-level resolution.
495 4. The $message_linecount variable is now updated for the maildir_tag option,
496 in the same way as $message_size, to reflect the real number of lines,
497 including any header additions or removals from transport.
499 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
500 Exim now selects entries randomly, to better scale in a cluster setup.
506 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
507 the flaw permitted the Exim run-time user to cause root to append to
508 arbitrary files of the attacker's choosing, with the content based
509 on content supplied by the attacker.
511 2. Exim now supports loading some lookup types at run-time, using your
512 platform's dlopen() functionality. This has limited platform support
513 and the intention is not to support every variant, it's limited to
514 dlopen(). This permits the main Exim binary to not be linked against
515 all the libraries needed for all the lookup types.
521 NOTE: this version is not guaranteed backwards-compatible, please read the
522 items below carefully
524 1. A new main configuration option, "openssl_options", is available if Exim
525 is built with SSL support provided by OpenSSL. The option allows
526 administrators to specify OpenSSL options to be used on connections;
527 typically this is to set bug compatibility features which the OpenSSL
528 developers have not enabled by default. There may be security
529 consequences for certain options, so these should not be changed
532 2. A new pipe transport option, "permit_coredumps", may help with problem
533 diagnosis in some scenarios. Note that Exim is typically installed as
534 a setuid binary, which on most OSes will inhibit coredumps by default,
535 so that safety mechanism would have to be overridden for this option to
536 be able to take effect.
538 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
539 Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
540 Note that this switches Exim to use a new API ("INSTREAM") and a future
541 release of ClamAV will remove support for the old API ("STREAM").
543 The av_scanner option, when set to "clamd", now takes an optional third
544 part, "local", which causes Exim to pass a filename to ClamAV instead of
545 the file content. This is the same behaviour as when clamd is pointed at
546 a Unix-domain socket. For example:
548 av_scanner = clamd:192.0.2.3 1234:local
550 ClamAV's ExtendedDetectionInfo response format is now handled.
552 4. There is now a -bmalware option, restricted to admin users. This option
553 takes one parameter, a filename, and scans that file with Exim's
554 malware-scanning framework. This is intended purely as a debugging aid
555 to ensure that Exim's scanning is working, not to replace other tools.
556 Note that the ACL framework is not invoked, so if av_scanner references
557 ACL variables without a fallback then this will fail.
559 5. There is a new expansion operator, "reverse_ip", which will reverse IP
560 addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
562 ${reverse_ip:192.0.2.4}
564 ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
565 -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
567 6. There is a new ACL control called "debug", to enable debug logging.
568 This allows selective logging of certain incoming transactions within
569 production environments, with some care. It takes two options, "tag"
570 and "opts"; "tag" is included in the filename of the log and "opts"
571 is used as per the -d<options> command-line option. Examples, which
572 don't all make sense in all contexts:
575 control = debug/tag=.$sender_host_address
576 control = debug/opts=+expand+acl
577 control = debug/tag=.$message_exim_id/opts=+expand
579 7. It has always been implicit in the design and the documentation that
580 "the Exim user" is not root. src/EDITME said that using root was
581 "very strongly discouraged". This is not enough to keep people from
582 shooting themselves in the foot in days when many don't configure Exim
583 themselves but via package build managers. The security consequences of
584 running various bits of network code are severe if there should be bugs in
585 them. As such, the Exim user may no longer be root. If configured
586 statically, Exim will refuse to build. If configured as ref:user then Exim
587 will exit shortly after start-up. If you must shoot yourself in the foot,
588 then henceforth you will have to maintain your own local patches to strip
591 8. There is a new expansion condition, bool_lax{}. Where bool{} uses the ACL
592 condition logic to determine truth/failure and will fail to expand many
593 strings, bool_lax{} uses the router condition logic, where most strings
595 Note: bool{00} is false, bool_lax{00} is true.
597 9. Routers now support multiple "condition" tests.
599 10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
600 Setting this allows an admin to define which entry in the tcpwrappers
601 config file will be used to control access to the daemon. This option
602 is only available when Exim is built with USE_TCP_WRAPPERS. The
603 default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
606 11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
607 the Exim run-time user, instead of root.
609 12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
610 is forced on. This is mitigated by the new build option
611 TRUSTED_CONFIG_LIST which defines a list of configuration files which
612 are trusted; one per line. If a config file is owned by root and matches
613 a pathname in the list, then it may be invoked by the Exim build-time
614 user without Exim relinquishing root privileges.
616 13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
617 trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
618 forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
619 include the main config. As a transition mechanism, we are temporarily
620 providing a work-around: the new build option WHITELIST_D_MACROS provides
621 a colon-separated list of macro names which may be overridden by the Exim
622 run-time user. The values of these macros are constrained to the regex
623 ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
629 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
630 writable, the other to locking of MBX folders (not mbox).
632 2. MySQL stored procedures are now supported.
634 3. The dkim_domain transport option is now a list, not a single string, and
635 messages will be signed for each element in the list (discarding
638 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
639 in the presence of multiple character strings within the RR. Prior to 4.70,
640 only the first string would be returned. The dnsdb lookup now, by default,
641 preserves the pre-4.70 semantics, but also now takes an extended output
642 separator specification. The separator can be followed by a semicolon, to
643 concatenate the individual text strings together with no join character,
644 or by a comma and a second separator character, in which case the text
645 strings within a TXT record are joined on that second character.
646 Administrators are reminded that DNS provides no ordering guarantees
647 between multiple records in an RRset. For example:
649 foo.example. IN TXT "a" "b" "c"
650 foo.example. IN TXT "d" "e" "f"
652 ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
653 ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
654 ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
660 1. Native DKIM support without an external library.
661 (Note that if no action to prevent it is taken, a straight upgrade will
662 result in DKIM verification of all signed incoming emails. See spec
663 for details on conditionally disabling)
665 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
667 3. There is now a bool{} expansion condition which maps certain strings to
668 true/false condition values (most likely of use in conjunction with the
669 and{} expansion operator).
671 4. The $spam_score, $spam_bar and $spam_report variables are now available
674 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
675 options, provided that Exim is invoked by an admin_user.
677 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
678 which increases compatibility with older clients at the cost of decreased
679 security. Don't set this unless you need to support such clients.
681 7. There is a new expansion operator, ${randint:...} which will produce a
682 "random" number less than the supplied integer. This randomness is
683 not guaranteed to be cryptographically strong, but depending upon how
684 Exim was built may be better than the most naive schemes.
686 8. Exim now explicitly ensures that SHA256 is available when linked against
689 9. The transport_filter_timeout option now applies to SMTP transports too.
695 1. Preliminary DKIM support in Experimental.
701 1. The body_linecount and body_zerocount C variables are now exported in the
704 2. When a dnslists lookup succeeds, the key that was looked up is now placed
705 in $dnslist_matched. When the key is an IP address, it is not reversed in
706 this variable (though it is, of course, in the actual lookup). In simple
709 deny dnslists = spamhaus.example
711 the key is also available in another variable (in this case,
712 $sender_host_address). In more complicated cases, however, this is not
713 true. For example, using a data lookup might generate a dnslists lookup
716 deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|...
718 If this condition succeeds, the value in $dnslist_matched might be
719 192.168.6.7 (for example).
721 3. Authenticators now have a client_condition option. When Exim is running as
722 a client, it skips an authenticator whose client_condition expansion yields
723 "0", "no", or "false". This can be used, for example, to skip plain text
724 authenticators when the connection is not encrypted by a setting such as:
726 client_condition = ${if !eq{$tls_cipher}{}}
728 Note that the 4.67 documentation states that $tls_cipher contains the
729 cipher used for incoming messages. In fact, during SMTP delivery, it
730 contains the cipher used for the delivery. The same is true for
733 4. There is now a -Mvc <message-id> option, which outputs a copy of the
734 message to the standard output, in RFC 2822 format. The option can be used
735 only by an admin user.
737 5. There is now a /noupdate option for the ratelimit ACL condition. It
738 computes the rate and checks the limit as normal, but it does not update
739 the saved data. This means that, in relevant ACLs, it is possible to lookup
740 the existence of a specified (or auto-generated) ratelimit key without
741 incrementing the ratelimit counter for that key.
743 In order for this to be useful, another ACL entry must set the rate
744 for the same key somewhere (otherwise it will always be zero).
749 # Read the rate; if it doesn't exist or is below the maximum
751 deny ratelimit = 100 / 5m / strict / noupdate
752 log_message = RATE: $sender_rate / $sender_rate_period \
753 (max $sender_rate_limit)
755 [... some other logic and tests...]
757 warn ratelimit = 100 / 5m / strict / per_cmd
758 log_message = RATE UPDATE: $sender_rate / $sender_rate_period \
759 (max $sender_rate_limit)
760 condition = ${if le{$sender_rate}{$sender_rate_limit}}
764 6. The variable $max_received_linelength contains the number of bytes in the
765 longest line that was received as part of the message, not counting the
766 line termination character(s).
768 7. Host lists can now include +ignore_defer and +include_defer, analagous to
769 +ignore_unknown and +include_unknown. These options should be used with
770 care, probably only in non-critical host lists such as whitelists.
772 8. There's a new option called queue_only_load_latch, which defaults true.
773 If set false when queue_only_load is greater than zero, Exim re-evaluates
774 the load for each incoming message in an SMTP session. Otherwise, once one
775 message is queued, the remainder are also.
777 9. There is a new ACL, specified by acl_smtp_notquit, which is run in most
778 cases when an SMTP session ends without sending QUIT. However, when Exim
779 itself is is bad trouble, such as being unable to write to its log files,
780 this ACL is not run, because it might try to do things (such as write to
781 log files) that make the situation even worse.
783 Like the QUIT ACL, this new ACL is provided to make it possible to gather
784 statistics. Whatever it returns (accept or deny) is immaterial. The "delay"
785 modifier is forbidden in this ACL.
787 When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set
788 to a string that indicates the reason for the termination of the SMTP
789 connection. The possible values are:
791 acl-drop Another ACL issued a "drop" command
792 bad-commands Too many unknown or non-mail commands
793 command-timeout Timeout while reading SMTP commands
794 connection-lost The SMTP connection has been lost
795 data-timeout Timeout while reading message data
796 local-scan-error The local_scan() function crashed
797 local-scan-timeout The local_scan() function timed out
798 signal-exit SIGTERM or SIGINT
799 synchronization-error SMTP synchronization error
800 tls-failed TLS failed to start
802 In most cases when an SMTP connection is closed without having received
803 QUIT, Exim sends an SMTP response message before actually closing the
804 connection. With the exception of acl-drop, the default message can be
805 overridden by the "message" modifier in the NOTQUIT ACL. In the case of a
806 "drop" verb in another ACL, it is the message from the other ACL that is
809 10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of
810 servers with individual queries. This is done by starting the query with
811 "servers=x:y:z;", where each item in the list may take one of two forms:
813 (1) If it is just a host name, the appropriate global option (mysql_servers
814 or pgsql_servers) is searched for a host of the same name, and the
815 remaining parameters (database, user, password) are taken from there.
817 (2) If it contains any slashes, it is taken as a complete parameter set.
819 The list of servers is used in exactly the same was as the global list.
820 Once a connection to a server has happened and a query has been
821 successfully executed, processing of the lookup ceases.
823 This feature is intended for use in master/slave situations where updates
824 are occurring, and one wants to update a master rather than a slave. If the
825 masters are in the list for reading, you might have:
827 mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
829 In an updating lookup, you could then write
831 ${lookup mysql{servers=master; UPDATE ...}
833 If, on the other hand, the master is not to be used for reading lookups:
835 pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
837 you can still update the master by
839 ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
841 11. The message_body_newlines option (default FALSE, for backwards
842 compatibility) can be used to control whether newlines are present in
843 $message_body and $message_body_end. If it is FALSE, they are replaced by
850 1. There is a new log selector called smtp_no_mail, which is not included in
851 the default setting. When it is set, a line is written to the main log
852 whenever an accepted SMTP connection terminates without having issued a
855 2. When an item in a dnslists list is followed by = and & and a list of IP
856 addresses, the behaviour was not clear when the lookup returned more than
857 one IP address. This has been solved by the addition of == and =& for "all"
858 rather than the default "any" matching.
860 3. Up till now, the only control over which cipher suites GnuTLS uses has been
861 for the cipher algorithms. New options have been added to allow some of the
862 other parameters to be varied.
864 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is
865 set, Exim compiles a runtime option called disable_fsync.
867 5. There is a new variable called $smtp_count_at_connection_start.
869 6. There's a new control called no_pipelining.
871 7. There are two new variables called $sending_ip_address and $sending_port.
872 These are set whenever an SMTP connection to another host has been set up.
874 8. The expansion of the helo_data option in the smtp transport now happens
875 after the connection to the server has been made.
877 9. There is a new expansion operator ${rfc2047d: that decodes strings that
878 are encoded as per RFC 2047.
880 10. There is a new log selector called "pid", which causes the current process
881 id to be added to every log line, in square brackets, immediately after the
884 11. Exim has been modified so that it flushes SMTP output before implementing
885 a delay in an ACL. It also flushes the output before performing a callout,
886 as this can take a substantial time. These behaviours can be disabled by
887 obeying control = no_delay_flush or control = no_callout_flush,
888 respectively, at some earlier stage of the connection.
890 12. There are two new expansion conditions that iterate over a list. They are
891 called forany and forall.
893 13. There's a new global option called dsn_from that can be used to vary the
894 contents of From: lines in bounces and other automatically generated
895 messages ("delivery status notifications" - hence the name of the option).
897 14. The smtp transport has a new option called hosts_avoid_pipelining.
899 15. By default, exigrep does case-insensitive matches. There is now a -I option
900 that makes it case-sensitive.
902 16. A number of new features ("addresses", "map", "filter", and "reduce") have
903 been added to string expansions to make it easier to process lists of
904 items, typically addresses.
906 17. There's a new ACL modifier called "continue". It does nothing of itself,
907 and processing of the ACL always continues with the next condition or
908 modifier. It is provided so that the side effects of expanding its argument
911 18. It is now possible to use newline and other control characters (those with
912 values less than 32, plus DEL) as separators in lists.
914 19. The exigrep utility now has a -v option, which inverts the matching
917 20. The host_find_failed option in the manualroute router can now be set to
924 No new features were added to 4.66.
930 No new features were added to 4.65.
936 1. ACL variables can now be given arbitrary names, as long as they start with
937 "acl_c" or "acl_m" (for connection variables and message variables), are at
938 least six characters long, with the sixth character being either a digit or
941 2. There is a new ACL modifier called log_reject_target. It makes it possible
942 to specify which logs are used for messages about ACL rejections.
944 3. There is a new authenticator called "dovecot". This is an interface to the
945 authentication facility of the Dovecot POP/IMAP server, which can support a
946 number of authentication methods.
948 4. The variable $message_headers_raw provides a concatenation of all the
949 messages's headers without any decoding. This is in contrast to
950 $message_headers, which does RFC2047 decoding on the header contents.
952 5. In a DNS black list, if two domain names, comma-separated, are given, the
953 second is used first to do an initial check, making use of any IP value
954 restrictions that are set. If there is a match, the first domain is used,
955 without any IP value restrictions, to get the TXT record.
957 6. All authenticators now have a server_condition option.
959 7. There is a new command-line option called -Mset. It is useful only in
960 conjunction with -be (that is, when testing string expansions). It must be
961 followed by a message id; Exim loads the given message from its spool
962 before doing the expansions.
964 8. Another similar new command-line option is called -bem. It operates like
965 -be except that it must be followed by the name of a file that contains a
968 9. When an address is delayed because of a 4xx response to a RCPT command, it
969 is now the combination of sender and recipient that is delayed in
970 subsequent queue runs until its retry time is reached.
972 10. Unary negation and the bitwise logical operators and, or, xor, not, and
973 shift, have been added to the eval: and eval10: expansion items.
975 11. The variables $interface_address and $interface_port have been renamed
976 as $received_ip_address and $received_port, to make it clear that they
977 relate to message reception rather than delivery. (The old names remain
978 available for compatibility.)
980 12. The "message" modifier can now be used on "accept" and "discard" acl verbs
981 to vary the message that is sent when an SMTP command is accepted.
987 1. There is a new Boolean option called filter_prepend_home for the redirect
990 2. There is a new acl, set by acl_not_smtp_start, which is run right at the
991 start of receiving a non-SMTP message, before any of the message has been
994 3. When an SMTP error message is specified in a "message" modifier in an ACL,
995 or in a :fail: or :defer: message in a redirect router, Exim now checks the
996 start of the message for an SMTP error code.
998 4. There is a new parameter for LDAP lookups called "referrals", which takes
999 one of the settings "follow" (the default) or "nofollow".
1001 5. Version 20070721.2 of exipick now included, offering these new options:
1003 After all other sorting options have bee processed, reverse order
1004 before displaying messages (-R is synonym).
1006 Randomize order of matching messages before displaying.
1008 Instead of displaying the matching messages, display the sum
1010 --sort <variable>[,<variable>...]
1011 Before displaying matching messages, sort the messages according to
1012 each messages value for each variable.
1014 Negate the value for every test (returns inverse output from the
1015 same criteria without --not).
1021 1. The ${readsocket expansion item now supports Internet domain sockets as well
1022 as Unix domain sockets. If the first argument begins "inet:", it must be of
1023 the form "inet:host:port". The port is mandatory; it may be a number or the
1024 name of a TCP port in /etc/services. The host may be a name, or it may be an
1025 IP address. An ip address may optionally be enclosed in square brackets.
1026 This is best for IPv6 addresses. For example:
1028 ${readsocket{inet:[::1]:1234}{<request data>}...
1030 Only a single host name may be given, but if looking it up yield more than
1031 one IP address, they are each tried in turn until a connection is made. Once
1032 a connection has been made, the behaviour is as for ${readsocket with a Unix
1035 2. If a redirect router sets up file or pipe deliveries for more than one
1036 incoming address, and the relevant transport has batch_max set greater than
1037 one, a batch delivery now occurs.
1039 3. The appendfile transport has a new option called maildirfolder_create_regex.
1040 Its value is a regular expression. For a maildir delivery, this is matched
1041 against the maildir directory; if it matches, Exim ensures that a
1042 maildirfolder file is created alongside the new, cur, and tmp directories.
1048 The documentation is up-to-date for the 4.61 release. Major new features since
1049 the 4.60 release are:
1051 . An option called disable_ipv6, to disable the use of IPv6 completely.
1053 . An increase in the number of ACL variables to 20 of each type.
1055 . A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1,
1056 $2, $3, (though those are still set) because the numeric variables get used
1057 for other things in complicated expansions.
1059 . The default for rfc1413_query_timeout has been changed from 30s to 5s.
1061 . It is possible to use setclassresources() on some BSD OS to control the
1062 resources used in pipe deliveries.
1064 . A new ACL modifier called add_header, which can be used with any verb.
1066 . More errors are detectable in retry rules.
1068 There are a number of other additions too.
1074 The documentation is up-to-date for the 4.60 release. Major new features since
1075 the 4.50 release are:
1077 . Support for SQLite.
1079 . Support for IGNOREQUOTA in LMTP.
1081 . Extensions to the "submission mode" features.
1083 . Support for Client SMTP Authorization (CSA).
1085 . Support for ratelimiting hosts and users.
1087 . New expansion items to help with the BATV "prvs" scheme.
1089 . A "match_ip" condition, that matches an IP address against a list.
1091 There are many more minor changes.
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