+Exim version 4.51
+-----------------
+
+TK/01 Added Yahoo DomainKeys support via libdomainkeys. See
+ doc/experimental-spec.txt for details. (http://domainkeys.sf.net)
+
+TK/02 Fix ACL "control" statement not being available in MIME ACL.
+
+TK/03 Fix ACL "regex" condition not being available in MIME ACL.
+
+PH/01 Installed a patch from the Sieve maintainer that allows -bf to be used
+ to test Sieve filters that use "vacation".
+
+PH/02 Installed a slightly modified version of Nikos Mavrogiannopoulos' patch
+ that changes the way the GnuTLS parameters are stored in the cache file.
+ The new format can be generated externally. For backward compatibility,
+ if the data in the cache doesn't make sense, Exim assumes it has read an
+ old-format file, and it generates new data and writes a new file. This
+ means that you can't go back to an older release without removing the
+ file.
+
+PH/03 A redirect router that has both "unseen" and "one_time" set does not
+ work if there are any delivery delays because "one_time" forces the
+ parent to be marked "delivered", so its unseen clone is never tried
+ again. For this reason, Exim now forbids the simultaneous setting of
+ these two options.
+
+PH/04 Change 4.11/85 fixed an obscure bug concerned with addresses that are
+ redirected to themselves ("homonym" addresses). Read the long ChangeLog
+ entry if you want to know the details. The fix, however, neglected to
+ consider the case when local delivery batching is involved. The test for
+ "previously delivered" was not happening when checking to see if an
+ address could be batched with a previous (undelivered) one; under
+ certain circumstances this could lead to multiple deliveries to the same
+ address. A one-line patch to add the appropriate test fixes the bug.
+
+PH/05 Renamed the macro SOCKLEN_T as EXIM_SOCKLEN_T because AIX uses SOCKLEN_T
+ in its include files, and this causes problems building Exim.
+
+PH/06 A number of "verify =" ACL conditions have no options (e.g. verify =
+ header_syntax) but Exim was just ignoring anything given after a slash.
+ In particular, this caused confusion with an attempt to use "verify =
+ reverse_host_lookup/defer_ok". An error is now given when options are
+ supplied for verify items that do not have them. (Maybe reverse_host_
+ lookup should have a defer_ok option, but that's a different point.)
+
+PH/07 Increase the size of the buffer for incoming SMTP commands from 512 (as
+ defined by RFC 821) to 2048, because there were problems with some AUTH
+ commands, and RFC 1869 says the size should be increased for extended
+ SMTP commands that take arguments.
+
+PH/08 Added ${dlfunc dynamically loaded function for expansion (code from Tony
+ Finch).
+
+PH/09 Previously, an attempt to use ${perl when it wasn't compiled gave an
+ "unknown" error; now it says that the functionality isn't in the binary.
+
+PH/10 Added a nasty fudge to try to recognize and flatten LDAP passwords in
+ an address' error message when a string expansion fails (syntax or
+ whatever). Otherwise not only does the password appear in the log, it may
+ also be put in a bounce message.
+
+PH/11 Installed exipick version 20050225.0 from John Jetmore.
+
+PH/12 If the last host in a fallback_hosts list was multihomed, only the first
+ of its addresses was ever tried. (Bugzilla bug #2.)
+
+PH/13 If "headers_add" in a transport didn't end in a newline, Exim printed
+ the result incorrectly in the debug output. (It correctly added a newline
+ to what was transported.)
+
+TF/01 Added $received_time.
+
+PH/14 Modified the default configuration to add an acl_smtp_data ACL, with
+ commented out examples of how to interface to a virus scanner and to
+ SpamAssassin. Also added commented examples of av_scanner and
+ spamd_address settings.
+
+PH/15 Further to TK/02 and TK/03 above, tidied up the tables of what conditions
+ and controls are allowed in which ACLs. There were a couple of minor
+ errors. Some of the entries in the conditions table (which is a table of
+ where they are NOT allowed) were getting very unwieldy; rewrote them as a
+ negation of where the condition IS allowed.
+
+PH/16 Installed updated OS/os.c-cygwin from the Cygwin maintainer.
+
+PH/17 The API for radiusclient changed at release 0.4.0. Unfortunately, the
+ header file does not have a version number, so I've had to invent a new
+ value for RADIUS_LIB_TYPE, namely "RADIUSCLIENTNEW" to request the new
+ API. The code is untested by me (my Linux distribution still has 0.3.2 of
+ radiusclient), but it was contributed by a Radius user.
+
+PH/18 Installed Lars Mainka's patch for the support of CRL collections in
+ files or directories, for OpenSSL.
+
+PH/19 When an Exim process that is running as root has to create an Exim log
+ file, it does so in a subprocess that runs as exim:exim so as to get the
+ ownership right at creation (otherwise, other Exim processes might see
+ the file with the wrong ownership). There was no test for failure of this
+ fork() call, which would lead to the process getting stuck as it waited
+ for a non-existent subprocess. Forks do occasionally fail when resources
+ run out. I reviewed all the other calls to fork(); they all seem to check
+ for failure.
+
+PH/20 When checking for unexpected SMTP input at connect time (before writing
+ the banner), Exim was not dealing correctly with a non-positive return
+ from the read() function. If the client had disconnected by this time,
+ the result was a log entry for a synchronization error with an empty
+ string after "input=" when read() returned zero. If read() returned -1
+ (an event I could not check), uninitialized data bytes were printed.
+ There were reports of junk text (parts of files, etc) appearing after
+ "input=".
+
+PH/21 Added acl_not_smtp_mime to allow for MIME scanning for non-SMTP messages.
+
+PH/22 Added support for macro redefinition, and (re)definition in between
+ driver and ACL definitions.
+
+