+PH/11 Added control=no_pipelining.
+
+PH/12 Added $sending_ip_address and $sending_port (mostly Magnus Holmgren's
+ patch, slightly modified), and move the expansion of helo_data till after
+ the connection is made in the smtp transport (so it can use these
+ values).
+
+PH/13 Added ${rfc2047d: to decoded RFC 2047 strings.
+
+PH/14 Added log_selector = +pid.
+
+PH/15 Flush SMTP output before delaying, unless control=no_delay_flush is set.
+
+PH/16 Add ${if forany and ${if forall.
+
+PH/17 Added dsn_from option to vary the From: line in DSNs.
+
+PH/18 Flush SMTP output before performing a callout, unless control =
+ no_callout_flush is set.
+
+PH/19 Change 4.64/PH/36 introduced a bug: when address_retry_include_sender
+ was true (the default) a successful delivery failed to delete the retry
+ item, thus causing premature timeout of the address. The bug is now
+ fixed.
+