CG_spam_filter.pl provides a content filter program for the Stalker CommuniGate Pro mail server that seeks to limit the number of outgoing spam your local users can send and incoming spam your system can receive. In essence, it is a throttling script that starts rejecting mail once a certain threshold is reached, such as X messages or recipients per minute. It is difficult to catch spammers until after the fact (when they have already done lots of damage and spammed many users); this is simply an effort to stop them in their tracks in real-time so you can deal with them later.
