> 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. Best regards Gerald
