This file contains descriptions of new features that have been added to Exim.
Before a formal release, there may be quite a lot of detail so that people can
-test from the snapshots or the CVS before the documentation is updated. Once
+test from the snapshots or the Git before the documentation is updated. Once
the documentation is updated, this file is reduced to a short list.
+Version 4.96
+------------
+
+ 1. A new ACL condition: seen. Records/tests a timestamp against a key.
+
+ 2. A variant of the "mask" expansion operator to give normalised IPv6.
+
+ 3. UTC output option for exim_dumpdb, exim_fixdb.
+
+ 4. An event for failing TLS connects to the daemon.
+
+ 5. The ACL "debug" control gains options "stop", "pretrigger" and "trigger".
+
+ 6. Query-style lookups are now checked for quoting, if the query string is
+ built using untrusted data ("tainted"). For now lack of quoting is merely
+ logged; a future release will upgrade this to an error.
+
+ 7. The expansion conditions match_<list-type> and inlist now set $value for
+ the expansion of the "true" result of the ${if}. With a static list, this
+ can be used for de-tainting.
+
+ 8. Recipient verify callouts now set $domain_data & $local_part_data, with
+ de-tainted values.
+
+Version 4.95
+------------
+
+ 1. The fast-ramp two phase queue run support, previously experimental, is
+ now supported by default.
+
+ 2. The native SRS support, previously experimental, is now supported. It is
+ not built unless specified in the Local/Makefile.
+
+ 3. TLS resumption support, previously experimental, is now supported and
+ included in default builds.
+
+ 4. Single-key LMDB lookups, previously experimental, are now supported.
+ The support is not built unless specified in the Local/Makefile.
+
+ 5. Option "message_linelength_limit" on the smtp transport to enforce (by
+ default) the RFC 998 character limit.
+
+ 6. An option to ignore the cache on a lookup.
+
+ 7. Quota checking during reception (i.e. at SMTP time) for appendfile-
+ transport-managed quotas.
+
+ 8. Sqlite lookups accept a "file=<path>" option to specify a per-operation
+ db file, replacing the previous prefix to the SQL string (which had
+ issues when the SQL used tainted values).
+
+ 9. Lsearch lookups accept a "ret=full" option, to return both the portion
+ of the line matching the key, and the remainder.
+
+10. A command-line option to have a daemon not create a notifier socket.
+
+11. Faster TLS startup. When various configuration options contain no
+ expandable elements, the information can be preloaded and cached rather
+ than the previous behaviour of always loading at startup time for every
+ connection. This helps particularly for the CA bundle.
+
+12. Proxy Protocol Timeout is configurable via "proxy_protocol_timeout"
+ main config option.
+
+13. Option "smtp_accept_max_per_connection" is now expanded.
+
+14. Log selector "queue_time_exclusive", enabled by default, to exclude the
+ time taken for reception from QT log elements.
+
+15. Main option "smtp_backlog_monitor", to set a level above which listen
+ socket backlogs are logged.
+
+16. Main option "hosts_require_helo", requiring HELO or EHLO before MAIL.
+
+17. A main config option "allow_insecure_tainted_data" allows to turn
+
+18. TLS ALPN handling. By default, refuse TLS connections that try to specify
+ a non-smtp (eg. http) use. Options for customising.
+
+19. Support for MacOS (darwin) has been dropped.
+
+
+Version 4.94
+------------
+
+ 1. EXPERIMENTAL_SRS_NATIVE optional build feature. See the experimental.spec
+ file.
+
+ 2. Channel-binding for authenticators is now supported under OpenSSL.
+ Previously it was GnuTLS-only.
+
+ 3. A msg:defer event.
+
+ 4. Client-side support in the gsasl authenticator. Tested against the
+ plaintext driver for PLAIN; only against itself for SCRAM-SHA-1 and
+ SCRAM-SHA-1-PLUS methods.
+
+ 5. Server-side support in the gsasl authenticator for encrypted passwords, as
+ an alternate for the existing plaintext.
+
+ 6. Variable $local_part_data now also set by router check_local_user option,
+ with an de-tainted version of $local_part.
+
+ 7. Named-list definitions can now be prefixed "hide" so that "-bP" commands do
+ not output the content. Previously this could only be done on options.
+
+ 8. As an experimental feature, the dovecot authentication driver supports inet
+ sockets. Previously it was unix-domain sockets only.
+
+ 9. The ACL control "queue_only" can also be spelled "queue", and now takes an
+ option "first_pass_route" to do the same as a "-odqs" on the command line.
+
+10. Items specified for the router and transport headers_remove option can use
+ a trailing asterisk to specify globbing.
+
+11. New $queue_size variable.
+
+12. New variables $local_part_{pre,suf}fix_v.
+
+13. New main option "sqlite_dbfile", for use in preference to prefixing the
+ lookup string. The older method fails when tainted variables are used
+ in the lookup, as the filename becomes tainted. The new method keeps the
+ filename separate.
+
+14. Options on the dsearch lookup, to return the full path and to filter
+ filetypes for matching.
+
+15. Options on pgsql and mysql lookups, to specify server separate from the
+ lookup string.
+
+16. An option on all single-key lookups, to return (on a hit) a de-tainted
+ version of the lookup key rather than the looked-up data.
+
+17. $domain_data and $local_part_data are now set by all list-match successes.
+ Previously only list items that performed lookups did so.
+ Also, matching list items that are tail-match or RE-match now set the
+ numeric variables $0 (etc) in the same way os other RE matches.
+
+18. Expansion item ${listquote {<char} {<item>}}.
+
+19. An option for the ${readsocket {}{}{}} expansion to make the result data
+ cacheable.
+
+20. dkim_verify_min_keysizes, a list of minimum acceptable public-key sizes.
+
+21. bounce_message_file and warn_message_file are now expanded before use.
+
+22. New main config option spf_smtp_comment_template to customise the
+ $spf_smtp_comment variable
+
+
+
+Version 4.93
+------------
+
+ 1. An "external" authenticator, per RFC 4422 Appendix A.
+
+ 2. A JSON lookup type, and JSON variants of the forall/any expansion conditions.
+
+ 3. Variables $tls_in_cipher_std, $tls_out_cipher_std giving the RFC names
+ for ciphersuites.
+
+ 4. Log_selectors "msg_id" (on by default) and "msg_id_created".
+
+ 5. A case_insensitive option for verify=not_blind.
+
+ 6. EXPERIMENTAL_TLS_RESUME optional build feature. See the experimental.spec
+ file.
+
+ 7. A main option exim_version to override the version Exim
+ reports in verious places ($exim_version, $version_number).
+
+ 8. Expansion operator ${sha2_N:} for N=256, 384, 512.
+
+ 9. Router variables, $r_... settable from router options and usable in routers
+ and transports.
+
+10. The spf lookup now supports IPv6.
+
+11. Main options for DKIM verify to filter hash and key types.
+
+12. With TLS1.3, support for full-chain OCSP stapling.
+
+13. Dual-certificate stacks on servers now support OCSP stapling, under OpenSSL.
+
+14: An smtp:ehlo transport event, for observability of the remote offered features.
+
+15: Support under OpenSSL for writing NSS-style key files for packet-capture
+ decode. The environment variable SSLKEYLOGFILE is used; if an absolute path
+ it must indicate a file under the spool directory; if relative the the spool
+ directory is prepended. Works on the server side only. Support under
+ GnuTLS was already there, being done purely by the library (server side
+ only, and exim must be run as root).
+
+16: Command-line option to move messages from one named queue to another.
+
+17. Variables $tls_in_ver, $tls_out_ver.
+
+
+Version 4.92
+--------------
+
+ 1. ${l_header:<name>} and ${l_h:<name>} expansion items, giving a colon-sep
+ list when there are multiple headers having a given name. This matters
+ when individual headers are wrapped onto multiple lines; with previous
+ facilities hard to parse.
+
+ 2. The ${readsocket } expansion item now takes a "tls" option, doing the
+ obvious thing.
+
+ 3. EXPERIMENTAL_REQUIRETLS and EXPERIMENTAL_PIPE_CONNECT optional build
+ features. See the experimental.spec file.
+
+ 4. If built with SUPPORT_I18N a "utf8_downconvert" option on the smtp transport.
+
+ 5. A "pipelining" log_selector.
+
+ 6. Builtin macros for supported log_selector and openssl_options values.
+
+ 7. JSON variants of the ${extract } expansion item.
+
+ 8. A "noutf8" debug option, for disabling the UTF-8 characters in debug output.
+
+ 9. TCP Fast Open support on MacOS.
+
+Version 4.91
+--------------
+
+ 1. Dual-certificate stacks on servers now support OCSP stapling, under GnuTLS
+ version 3.5.6 or later.
+
+ 2. DANE is now supported under GnuTLS version 3.0.0 or later. Both GnuTLS and
+ OpenSSL versions are moved to mainline support from Experimental.
+ New SMTP transport option "dane_require_tls_ciphers".
+
+ 3. Feature macros for the compiled-in set of malware scanner interfaces.
+
+ 4. SPF support is promoted from Experimental to mainline status. The template
+ src/EDITME makefile does not enable its inclusion.
+
+ 5. Logging control for DKIM verification. The existing DKIM log line is
+ controlled by a "dkim_verbose" selector which is _not_ enabled by default.
+ A new tag "DKIM=<domain>" is added to <= lines by default, controlled by
+ a "dkim" log_selector.
+
+ 6. Receive duration on <= lines, under a new log_selector "receive_time".
+
+ 7. Options "ipv4_only" and "ipv4_prefer" on the dnslookup router and on
+ routing rules in the manualroute router.
+
+ 8. Expansion item ${sha3:<string>} / ${sha3_<N>:<string>} now also supported
+ under OpenSSL version 1.1.1 or later.
+
+ 9. DKIM operations can now use the Ed25519 algorithm in addition to RSA, under
+ GnuTLS 3.6.0 or OpenSSL 1.1.1 or later.
+
+10. Builtin feature-macros _CRYPTO_HASH_SHA3 and _CRYPTO_SIGN_ED25519, library
+ version dependent.
+
+11. "exim -bP macro <name>" returns caller-usable status.
+
+12. Expansion item ${authresults {<machine>}} for creating an
+ Authentication-Results: header.
+
+13. EXPERIMENTAL_ARC. See the experimental.spec file.
+ See also new util/renew-opendmarc-tlds.sh script for use with DMARC/ARC.
+
+14: A dane:fail event, intended to facilitate reporting.
+
+15. "Lightweight" support for Redis Cluster. Requires redis_servers list to
+ contain all the servers in the cluster, all of which must be reachable from
+ the running exim instance. If the cluster has master/slave replication, the
+ list must contain all the master and slave servers.
+
+16. Add an option to the Avast scanner interface: "pass_unscanned". This
+ allows to treat unscanned files as clean. Files may be unscanned for
+ several reasons: decompression bombs, broken archives.
+
+
+Version 4.90
+------------
+
+ 1. PKG_CONFIG_PATH can now be set in Local/Makefile;
+ wildcards will be expanded, values are collapsed.
+
+ 2. The ${readsocket } expansion now takes an option to not shutdown the
+ connection after sending the query string. The default remains to do so.
+
+ 3. An smtp transport option "hosts_noproxy_tls" to control whether multiple
+ deliveries on a single TCP connection can maintain a TLS connection
+ open. By default disabled for all hosts, doing so saves the cost of
+ making new TLS sessions, at the cost of having to proxy the data via
+ another process. Logging is also affected.
+
+ 4. A malware connection type for the FPSCAND protocol.
+
+ 5. An option for recipient verify callouts to hold the connection open for
+ further recipients and for delivery.
+
+ 6. The reproducible build $SOURCE_DATE_EPOCH environment variable is now
+ supported.
+
+ 7. Optionally, an alternate format for spool data-files which matches the
+ wire format - meaning more efficient reception and transmission (at the
+ cost of difficulty with standard Unix tools). Only used for messages
+ received using the ESMTP CHUNKING option, and when a new main-section
+ option "spool_wireformat" (false by default) is set.
+
+ 8. New main configuration option "commandline_checks_require_admin" to
+ restrict who can use various introspection options.
+
+ 9. New option modifier "no_check" for quota and quota_filecount
+ appendfile transport.
+
+10. Variable $smtp_command_history returning a comma-sep list of recent
+ SMTP commands.
+
+11. Millisecond timetamps in logs, on log_selector "millisec". Also affects
+ log elements QT, DT and D, and timstamps in debug output.
+
+12. TCP Fast Open logging. As a server, logs when the SMTP banner was sent
+ while still in SYN_RECV state; as a client logs when the connection
+ is opened with a TFO cookie.
+
+13. DKIM support for multiple signing, by domain and/or key-selector.
+ DKIM support for multiple hashes, and for alternate-identity tags.
+ Builtin macro with default list of signed headers.
+ Better syntax for specifying oversigning.
+ The DKIM ACL can override verification status, and status is visible in
+ the data ACL.
+
+14. Exipick understands -C|--config for an alternative Exim
+ configuration file.
+
+15. TCP Fast Open used, with data-on-SYN, for client SMTP via SOCKS5 proxy,
+ for ${readsocket } expansions, and for ClamAV.
+
+16. The "-be" expansion test mode now supports macros. Macros are expanded
+ in test lines, and new macros can be defined.
+
+17. Support for server-side dual-certificate-stacks (eg. RSA + ECDSA).
+
+
+Version 4.89
+------------
+
+ 1. Allow relative config file names for ".include"
+
+ 2. A main-section config option "debug_store" to control the checks on
+ variable locations during store-reset. Normally false but can be enabled
+ when a memory corruption issue is suspected on a production system.
+
+
Version 4.88
------------
N can be 224, 256 (default), 384, 512.
With GnuTLS 3.5.0 or later, only.
- 5. Facility for named queues: A commandline argument can specify
+ 5. Facility for named queues: A command-line argument can specify
the queue name for a queue operation, and an ACL modifier can set
the queue to be used for a message. A $queue_name variable gives
visibility.
+ 6. New expansion operators base32/base32d.
+
+ 7. The CHUNKING ESMTP extension from RFC 3030. May give some slight
+ performance increase and network load decrease. Main config option
+ chunking_advertise_hosts, and smtp transport option hosts_try_chunking
+ for control.
+
+ 8. LMDB lookup support, as Experimental. Patch supplied by Andrew Colin Kissa.
+
+ 9. Expansion operator escape8bit, like escape but not touching newline etc..
+
+10. Feature macros, generated from compile options. All start with "_HAVE_"
+ and go on with some roughly recognisable name. Driver macros, for
+ router, transport and authentication drivers; names starting with "_DRIVER_".
+ Option macros, for each configuration-file option; all start with "_OPT_".
+ Use the "-bP macros" command-line option to see what is present.
+
+11. Integer values for options can take a "G" multiplier.
+
+12. defer=pass option for the ACL control cutthrough_delivery, to reflect 4xx
+ returns from the target back to the initiator, rather than spooling the
+ message.
+
+13. New built-in constants available for tls_dhparam and default changed.
+
+14. If built with EXPERIMENTAL_QUEUEFILE, a queuefile transport, for writing
+ out copies of the message spool files for use by 3rd-party scanners.
+
+15. A new option on the smtp transport, hosts_try_fastopen. If the system
+ supports it (on Linux it must be enabled in the kernel by the sysadmin)
+ try to use RFC 7413 "TCP Fast Open". No data is sent on the SYN segment
+ but it permits a peer that also supports the facility to send its SMTP
+ banner immediately after the SYN,ACK segment rather then waiting for
+ another ACK - so saving up to one roundtrip time. Because it requires
+ previous communication with the peer (we save a cookie from it) this
+ will only become active on frequently-contacted destinations.
+
+16. A new syslog_pid option to suppress PID duplication in syslog lines.
+
Version 4.87
------------
synonym of the latter). Add support in base64 for certificates.
8. New main configuration option "bounce_return_linesize_limit" to
- avoid oversize bodies in bounces. The dafault value matches RFC
+ avoid oversize bodies in bounces. The default value matches RFC
limits.
9. New $initial_cwd expansion variable.
5. Assorted options on malware= and spam= scanners.
- 6. A commandline option to write a comment into the logfile.
+ 6. A command-line option to write a comment into the logfile.
7. If built with EXPERIMENTAL_SOCKS feature enabled, the smtp transport can
be configured to make connections via socks5 proxies.
14. Main option "dns_trust_aa" for trusting your local nameserver at the
same level as DNSSEC.
-
Version 4.85
------------
1. If built with EXPERIMENTAL_DANE feature enabled, Exim will follow the
- DANE smtp draft to assess a secure chain of trust of the certificate
+ DANE SMTP draft to assess a secure chain of trust of the certificate
used to establish the TLS connection based on a TLSA record in the
domain of the sender.
12. OCSP stapling is now supported by default.
13. If built with the EXPERIMENTAL_DSN feature enabled, Exim will output
- Delivery Status Notification messages in MIME format, and negociate
+ Delivery Status Notification messages in MIME format, and negotiate
DSN features per RFC 3461.
ignored.
7. New cutthrough routing feature. Requested by a "control = cutthrough_delivery"
- ACL modifier; works for single-recipient mails which are recieved on and
+ ACL modifier; works for single-recipient mails which are received on and
deliverable via SMTP. Using the connection made for a recipient verify,
if requested before the verify, or a new one made for the purpose while
the inbound connection is still active. The bulk of the mail item is copied
direct from the inbound socket to the outbound (as well as the spool file).
When the source notifies the end of data, the data acceptance by the destination
- is negociated before the acceptance is sent to the source. If the destination
+ is negotiated before the acceptance is sent to the source. If the destination
does not accept the mail item, for example due to content-scanning, the item
is not accepted from the source and therefore there is no need to generate
a bounce mail. This is of benefit when providing a secondary-MX service.
The downside is that delays are under the control of the ultimate destination
system not your own.
- The Recieved-by: header on items delivered by cutthrough is generated
+ The Received-by: header on items delivered by cutthrough is generated
early in reception rather than at the end; this will affect any timestamp
included. The log line showing delivery is recorded before that showing
reception; it uses a new ">>" tag instead of "=>".
16. New authenticated_sender logging option, adding to log field "A".
17. New expansion variables $router_name and $transport_name. Useful
- particularly for debug_print as -bt commandline option does not
+ particularly for debug_print as -bt command-line option does not
require privilege whereas -d does.
18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
It adds new expansion variables $dmarc_ar_header, $dmarc_status,
$dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
dmarc_status. It adds new control flags dmarc_disable_verify and
- dmarc_enable_forensic.
+ dmarc_enable_forensic. The default for the dmarc_tld_file option is
+ "/etc/exim/opendmarc.tlds" and can be changed via EDITME.
22. Add expansion variable $authenticated_fail_id, which is the username
provided to the authentication method which failed. It is available
for use in subsequent ACL processing (typically quit or notquit ACLs).
-23. New ACL modifer "udpsend" can construct a UDP packet to send to a given
+23. New ACL modifier "udpsend" can construct a UDP packet to send to a given
UDP host and port.
24. New ${hexquote:..string..} expansion operator converts non-printable
longest line that was received as part of the message, not counting the
line termination character(s).
- 7. Host lists can now include +ignore_defer and +include_defer, analagous to
+ 7. Host lists can now include +ignore_defer and +include_defer, analogous to
+ignore_unknown and +include_unknown. These options should be used with
care, probably only in non-critical host lists such as whitelists.