Filtering outgoing email

["Kellogg, Brian D." <bkellogg () SBU EDU>]

We've been the victim of a phishing scam that made it through our
incoming spam filter.  The phisher used the compromised accounts to send
spam via Outlook Web Access.  Just wondering what inexpensive/reliable
methods others are using to filter outbound email and catch any accounts
showing a huge volume of outbound spam.  Thanks...

 
 
Thank you,
 
Brian Kellogg
Network Services Manager
St. Bonaventure University
716-375-4092