Secondary MX servers are a source of accept-then-bounce spam when they don’t reject mail with “recipient unknown”, and when they don’t enforce the same anti-spam policy as the primary MX. Such servers may eventually become blacklisted. That´s the reason why I share the mysql-database between the primary and secondary MX […]
Robert Schetterer´s post (Botnet-Angriffe mit rsyslog und iptables recent module abwehren) to immediately add a IP by rsyslog to the firewall when they were rejected by postscreen has led me to present my solution here for syslog-ng. I do not use a pipe, but contribute about syslog-ng the appropriate IP […]
I use postscreen postscreen to prevent spam mails. Potential spam messages are rejected directly before they reach the server and the content must be scanned. You shouldn´t use postscreen if a Mail-User-Agents (MUAs) should be able to connect. Usually the TCP-Port 25 is only used for Mail-Transfer-Agents (MTAa) since MUAs […]