+PH/17 If a delivery to a pipe, file, or autoreply was deferred, Exim was not
+ using the correct key (the original address) when searching the retry
+ rules in order to find which one to use for generating the retry hint.
+
+PH/18 If quota_warn_message contains a From: header, Exim now refrains from
+ adding the default one. Similarly, if it contains a Reply-To: header, the
+ errors_reply_to option, if set, is not used.
+
+PH/19 When calculating a retry time, Exim used to measure the "time since
+ failure" by looking at the "first failed" field in the retry record. Now
+ it does not use this if it is later than than the arrival time of the
+ message. Instead it uses the arrival time. This makes for better
+ behaviour in cases where some deliveries succeed, thus re-setting the
+ "first failed" field. An example is a quota failure for a huge message
+ when small messages continue to be delivered. Without this change, the
+ "time since failure" will always be short, possible causing more frequent
+ delivery attempts for the huge message than are intended.
+
+PH/20 Added $auth1, $auth2, $auth3 to contain authentication data (as well as
+ $1, $2, $3) because the numerical variables can be reset during some
+ expansion items (e.g. "match"), thereby losing the authentication data.
+
+PH/21 Make -bV show the size of off_t variables so that the test suite can
+ decide whether to run tests for quotas > 2G.
+
+PH/22 Test the values given for quota, quota_filecount, quota_warn_threshold,
+ mailbox_size, and mailbox_filecount in the appendfile transport. If a
+ filecount value is greater than 2G or if a quota value is greater than 2G
+ on a system where the size of off_t is not greater than 4, a panic error
+ is given.
+