JH/02 Rework error string handling in DKIM to pass more info back to callers.
This permits better logging.
+JH/03 Rework the transport continued-connection mechanism: when TLS is active,
+ do not close it down and have the child transport start it up again on
+ the passed-on TCP connection. Instead, proxy the child (and any
+ subsequent ones) for TLS via a unix-domain socket channel. Logging is
+ affected: the continued delivery log lines do not have any DNSSEC, TLS
+ Certificate or OCSP information. TLS cipher information is still logged.
+
+JH/04 Shorten the log line for daemon startup by collapsing adjacent sets of
+ identical IP addresses on different listening ports. Will also affect
+ "exiwhat" output.
+
+PP/02 Bug 2070: uClibc defines __GLIBC__ without providing glibc headers;
+ add noisy ifdef guards to special-case this sillyness.
+ Patch from Bernd Kuhls.
+
+JH/05 Tighten up the checking in isip4 (et al): dotted-quad components larger
+ than 255 are no longer allowed.
+
+JH/06 Default openssl_options to include +no_ticket, to reduce load on peers.
+ Disable the session-cache too, which might reduce our load. Since we
+ currrectly use a new context for every connection, both as server and
+ client, there is no benefit for these.
+ GnuTLS appears to not support tickets server-side by default (we don't
+ call gnutls_session_ticket_enable_server()) but client side is enabled
+ by default on recent versions (3.1.3 +) unless the PFS priority string
+ is used (3.2.4 +).
+
+PP/03 Add $SOURCE_DATE_EPOCH support for reproducible builds, per spec at
+ <https://reproducible-builds.org/specs/source-date-epoch/>.
+
+JH/07 Fix smtp transport use of limited max_rcpt under mua_wrapper. Previously
+ the check for any unsuccessful recipients did not notice the limit, and
+ erroneously found still-pending ones.
+
+JH/08 Pipeline CHUNKING command and data together, on kernels that support
+ MSG_MORE. Only in-clear (not on TLS connections).
+
+JH/09 Avoid using a temporary file during transport using dkim. Unless a
+ transport-filter is involved we can buffer the headers in memory for
+ creating the signature, and read the spool data file once for the
+ signature and again for transmission.
+
+JH/10 Enable use of sendfile in Linux builds as default. It was disabled in
+ 4.77 as the kernel support then wasn't solid, having issues in 64bit
+ mode. Now, it's been long enough. Add support for FreeBSD also.
+
+JH/11 Bug 2104: Fix continued use of a transport connection with TLS. In the
+ case where the routing stage had gathered several addresses to send to
+ a host before calling the transport for the first, we previously failed
+ to close down TLS in the old transport process before passing the TCP
+ connection to the new process. The new one sent a STARTTLS command
+ which naturally failed, giving a failed delivery and bloating the retry
+ database. Investigation and fix prototype from Wolfgang Breyha.
+
+JH/12 Fix check on SMTP command input synchronisation. Previously there were
+ false-negatives in the check that the sender had not preempted a response
+ or prompt from Exim (running as a server), due to that code's lack of
+ awareness of the SMTP input buffering.
+
+PP/04 Add commandline_checks_require_admin option.
+ Exim drops privileges sanely, various checks such as -be aren't a
+ security problem, as long as you trust local users with access to their
+ own account. When invoked by services which pass untrusted data to
+ Exim, this might be an issue. Set this option in main configuration
+ AND make fixes to the calling application, such as using `--` to stop
+ processing options.
+
+JH/13 Do pipelining under TLS. Previously, although safe, no advantage was
+ taken. Now take care to pack both (client) MAIL,RCPT,DATA, and (server)
+ responses to those, into a single TLS record each way (this usually means
+ a single packet). As a side issue, smtp_enforce_sync now works on TLS
+ connections.
+
+PP/05 OpenSSL/1.1: use DH_bits() for more accurate DH param sizes. This
+ affects you only if you're dancing at the edge of the param size limits.
+ If you are, and this message makes sense to you, then: raise the
+ configured limit or use OpenSSL 1.1. Nothing we can do for older
+ versions.
+
Exim version 4.89
-----------------
JH/18 Bug 2061: Fix ${extract } corrupting an enclosing ${reduce } $value.
+JH/19 Fix reference counting bug in routing-generated-address tracking.
+
Exim version 4.88
-----------------