+PH/18 Reversed 4.52/PH/17 because the HP-UX user found it wasn't the cause
+ of the problem. Specifically, suggested +O2 rather than +O1 for the
+ HP-UX compiler.
+
+PH/19 Added sqlite_lock_timeout option (David Woodhouse's patch).
+
+PH/20 If a delivery was routed to a non-standard port by means of an SRV
+ record, the port was not correctly logged when the outgoing_port log
+ selector was set (it logged the transort's default port).
+
+PH/21 Added support for host-specific ports to manualroute, queryprogram,
+ fallback_hosts, and "hosts" in the smtp transport.
+
+PH/22 If the log selector "outgoing_port" is set, the port is now also given on
+ host errors such as "Connection refused".
+
+PH/23 Applied a patch to fix problems with exim-4.52 while doing radius
+ authentication with radiusclient 0.4.9:
+
+ - Error returned from rc_read_config was caught wrongly
+ - Username/password not passed on to radius server due to wrong length.
+
+ The presumption is that some radiusclient API changes for 4.51/PH/17
+ were not taken care of correctly. The code is still untested by me (my
+ Linux distribution still has 0.3.2 of radiusclient), but it was
+ contributed by a Radius user.
+
+PH/24 When doing a callout, the value of $domain wasn't set correctly when
+ expanding the "port" option of the smtp transport.
+
+TK/04 MIME ACL: Fix buffer underrun that occurs when EOF condition is met
+ while reading a MIME header. Thanks to Tom Hughes for a patch.
+
+PH/24 Include config.h inside local_scan.h so that configuration settings are
+ available.
+
+PH/25 Make $smtp_command_argument available after all SMTP commands. This means
+ that in an ACL for RCPT (for example), you can examine exactly what was
+ received.
+
+PH/26 Exim was recognizing IPv6 addresses of the form [IPv6:....] in EHLO
+ commands, but it was not correctly comparing the address with the actual
+ client host address. Thus, it would show the EHLO address in Received:
+ header lines when this was not necessary.
+
+PH/27 Added the % operator to ${eval:}.
+
+PH/28 Exim tries to create and chdir to its spool directory when it starts;
+ it should be ignoring failures (because with -C, for example, it has lost
+ privilege). It wasn't ignoring creation failures other than "already
+ exists".
+
+PH/29 Added "crypteq" to the list of supported features that Exim outputs when
+ -bV or -d is used.
+
+PH/30 Fixed (presumably very longstanding) bug in exim_dbmbuild: if it failed
+ because an input line was too long, either on its own, or by virtue of
+ too many continuations, the temporary file was not being removed.
+