Gerald Galster skrev den 2020-07-27 14:40:
Thanks, Gerald. I also have this in my main.cf configuration file:
smtpd_sender_restrictions =
permit_mynetworks,
reject_non_fqdn_sender,
reject_unknown_sender_domain,
check_client_access cidr:/etc/postfix/blacklist_cidr,
permit
Shouldn't the reject_non_fqdn_sender or reject_unknown_sender_domain
restrictions have caught this?
It would be a bad idea to generally block "<>"/null sender/bounces,
because these are (mostly) error mails that inform you something
unusual
happend. Besides "<>" is a valid return path (defined by rfc).
In your case you could try smtpd_client_restrictions:
http://www.postfix.org/postconf.5.html#reject_unknown_client_hostname
Received: from klwr.golfgenius.com (unknown [138.128.241.193])
This IP does not seem to have a valid DNS PTR record, which nowadays
is a requirement for mailservers.
add milter-reqex to postfix can solve all the above with regex rules,
and <> is only valid for mynetwork servers, most others is spam bounces
