On 13 Mar 2018, at 22:51 (-0400), li...@lazygranch.com wrote:
I'm getting hit every 10 minutes from this spammer. As you can see I
am
rejecting the message. I wonder if the offending email server doesn't
know the message is being rejected?
It's not being rejected, it's being deferred.
Mar 13 23:28:58 centos-1gb-sfo1-01 postfix/smtpd[22153]: NOQUEUE:
reject: RCPT from unknown[113.247.6.67]: 450 4.7.1 Client host
rejected: cannot find your reverse hostname, [113.247.6.67];
from=<sale...@tradepro.net> to=<li...@lazygranch.com> proto=ESMTP
helo=<mail.port25.com>
A '450' response code is explicitly telling the client to try again
later.
If you are using reject_unknown_reverse_client_hostname, it is mostly
safe to set unknown_client_reject_code to '550' instead of the default
'450' but if you are using reject_unknown_client_hostname (which is
unsafe for most sites) you should not.
OR: if you don't get any legitimate mail from Hunan, Chongqing, or Hong
Kong you can probably safely block 113.240.0.0/12 from talking at all to
your SMTP port (or just the /13 to limit it to Hunan.)
--
Bill Cole
b...@scconsult.com or billc...@apache.org
(AKA @grumpybozo and many *@billmail.scconsult.com addresses)
Currently Seeking Steady Work: https://linkedin.com/in/billcole
