It would be nice to have an option to enable logging to SYSLOG the SMTP
protocol errors that occur during a SMTP session, along with the SMTP
commands that caused them.
As far as I know, currently these errors can be logged to SYSLOG only by
one of the following methods:
1. By making the SMTP service more verbose.
In this case a large amount of additional data is being logged, which
might not always be desirable.
2. By adding "protocol" to the list of notify_classes.
In this case an transcript email is sent to "postmaster" (or to a
configured recipient) for every SMTP session that contains errors, which
again might not always be desirable and might be an overkill.
For example the following transaction will not show any errors in SYSLOG:
In: AUTH LOGIN
Out: 503 5.5.1 Error: authentication not enabled
In: QUIT
Out: 221 2.0.0 Bye
Cheers,
K.
