+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.
+