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.next
+--------------
+
+ 1. EXPERIMENTAL_SRS_NATIVE optional build feature. See the experimental.spec
+ file.
+
+ 2. Variables $tls_in_ver, $tls_out_ver.
+
+ 3. Channel-binding for authenticators is now supported under OpenSSL.
+ Previously it was GnuTLS-only.
+
+
+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. Under GnuTLS, 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.
+
+
+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
------------
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.
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
------------
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 corrution issue is suspected on a production system.
+ when a memory corruption issue is suspected on a production system.
Version 4.88
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.