+PH/03 When creating an mbox file for a virus/spam scan, use fseek() instead of
+ fread() to skip over the body file's header line, because in Cygwin the
+ header line is locked and is inaccessible.
+
+PH/04 Added $message_exim_id, ultimately to replace $message_id (they will both
+ co-exist for some time) to make it clear that it is the Exim ID that is
+ referenced, not the Message-ID: header line.
+
+PH/05 Replaced all Tom's calls to snprintf() with calls to the internal
+ string_format() function, because snprintf() does not exist on all
+ operating systems.
+
+PH/06 The use of forbid_filter_existstest now also locks out the use of the
+ ${stat: expansion item.
+
+PH/07 Changed "SMTP protocol violation: synchronization error" into "SMTP
+ protocol synchronization error", to keep the pedants happy.
+
+PH/08 Arrange for USE_INET_NTOA_FIX to be set in config.h for AIX systems as
+ well as for IRIX systems, when gcc is being used. See the host.c source
+ file for comments.
+
+PH/09 Installed latest Cygwin configuration files from the Cygwin maintainer.
+
+PH/10 Named domain lists were not working if used in a queue_smtp_domains
+ setting.
+
+PH/11 Added support for the IGNOREQUOTA extension to LMTP, both to the lmtp
+ transport and to the smtp transport in LMTP mode.
+
+TK/02 Remove one case of BASE64 error detection FTTB (undocumented anyway).
+
+PH/12 There was a missing call to search_tidyup() before the fork() in rda.c to
+ run a filter in a subprocess. This could lead to confusion in subsequent
+ lookups in the parent process. There should also be a search_tidyup() at
+ the end of the subprocess.
+
+PH/13 Previously, if "verify = helo" was set in an ACL, the condition was true
+ only if the host matched helo_try_verify_hosts, which caused the
+ verification to occur when the EHLO/HELO command was issued. The ACL just
+ tested the remembered result. Now, if a previous verification attempt has
+ not happened, "verify = helo" does it there and then.
+
+JJ/01 exipick: added $message_exim_id variable (see 4.53-PH/04)
+
+TK/03 Fix log output including CR from clamd.
+
+PH/14 A reference to $reply_address when Reply-to: was empty and From: did not
+ exist provoked a memory error which could cause a segfault.
+
+PH/15 Installed PCRE 6.2
+
+PH/17 Defined BIND_8_COMPAT in the Darwin os.h file.
+
+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.
+