checkMX is a Perl daemon which monitors remote MX servers for a domain's overall health. If all the MX hosts are down and the domain can no longer receive mail, checkMX updates the Postfix relay_domains file so it will start accepting mail for the broken domain. Once the domain can start accepting mail on its own, checkmx will flush the mail queue for delivery and remove it from postfix relay_domains file. This prevents spammers from using the backup MX server as a spam vector.
|Tags||Mail Management Postfix Mail Relay Perl Deamon|