An extra log_selector, "protocol_detail" has been added in the default build.
The name may change in future, hence the Experimenal status.
-Currrently the only effect is to enable logging, under OpenSSL,
+Currrently the only effect is to enable logging, under TLS,
of a TCP RST received directly after a QUIT (in server mode).
Outlook is consistently doing this; not waiting for the SMTP response