[toaster] Fighting SPAM

[Peter Maag]

Bill and Others, I am paranoid about people using my server as a relay, andam considering having users use there ISP’s SMTP server for outgoing mail.  What I would like to do is to monitor the amount of mail the server is sending at any given moment in time.  If a user is sending more mail than a predefined limit, I would like to turn off their relay access to the server via IPTables, etc.   Currently, the server is running the latest toaster patch, and is only supporting around 15 users.  These users use plain POP authentication for checking their mail.  Obviously the server is using POP before SMTP to authenticate users.  The reason I am concerned is that POP is unencrypted.  So, is there any way I can block the amount of mail a user can send in a given amount of time(perhaps 50messages/hour)?  If not, how would you monitor the mail leaving the server? I would think this would be a pretty fair allotment for my average user base.  Any suggestions?  Thanks again for the help.               Peter Maag