MRob:
> Lately it looks like some zombie bot farm is connecting to submission
> (and looks to do nothing except connect), causing many of these in the
> logs:
>
> Oct 28 06:15:35 mail postfix/smtpd[12941]: warning: hostname x.y.z does
> not resolve to address 11.22.33.44: Name or service not known
This is logged because it affects name-based Postfix features such
as check_client_access, check_client_ns_access and so on. Without
such logging, trouble shooting after-the-fact would be harder.
Instead, Postfix could log
warning: client hostname unavailable for check_client_access:
hostname x.y.z does not resolve to address 11.22.33.44: Name
or service not known
And that would be logged for each affected feature, i.e. multiple
times per SMTP session.
If the presence of the line in the logfile bothers you: use grep.
Wietse
