The daily pflogsumm report shows that (in recent days) 60~93% of
attempts to connect are rejected, and bounce-off Postfix's settings, eg
450 4.7.1 <00nyBxbT>: Helo command rejected: Host not found;
proto=SMTP helo=<00nyBxbT> (total: 1)
1 115.213.249.159 (<>)
The EHLO string changes with each attempt, but the IP address may be the
same for dozens, hundreds, or thousands of these.
The server moves along quite calmly, without stressing either RAM or CPU.
Maybe: if it ain't broke, don't fix it?
That said, is Postfix the best tool for this job, or should something
else (maybe like Fail2Ban) act as Bouncer, by pre-processing such
connections? Will welcome rationale(s)...
--
Regards,
=dn
