+ 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
+------------
+
+ 1. The new perl_taintmode option allows to run the embedded perl
+ interpreter in taint mode.
+
+ 2. New log_selector: dnssec, adds a "DS" tag to acceptance and delivery lines.
+
+ 3. Speculative debugging, via a "kill" option to the "control=debug" ACL
+ modifier.
+
+ 4. New expansion item ${sha3:<string>} / ${sha3_<N>:<string>}.
+ N can be 224, 256 (default), 384, 512.
+ With GnuTLS 3.5.0 or later, only.
+
+ 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.