+JH/11 Add A= logging on delivery lines, and a client_set_id option on
+ authenticators.
+
+JH/12 Add optional authenticated_sender logging to A= and a log_selector
+ for control.
+
+PP/12 Unbreak server_set_id for NTLM/SPA auth, broken by 4.80 PP/29.
+
+PP/13 Dovecot auth: log better reason to rejectlog if Dovecot did not
+ advertise SMTP AUTH mechanism to us, instead of a generic
+ protocol violation error. Also, make Exim more robust to bad
+ data from the Dovecot auth socket.
+