Spam is here to stay. While we can't get rid of spam entirely, there are tools to help you manage the amount of spam in your Inbox.
SpamAssassin allows you to set thresholds for the both the labeling of messages as spam and the score at which something should be done with the mail. Spam Assassin sits at the perimeter of our mail servers and scans mail before it gets to your inbox. Users can configure many settings in the Spam Assassin Configuration application in WesPortal (EPortfolio).
Outlook also has Junk mail filtering tools and the ability to write specific rules. Using Outlook built-in tools in conjunction with Spam Assassin is the best defense. Since false positives can occur, you should choose your settings based on your tolerance for an occasional message going to your Junk folder.