How does Server side filtering help me?  
   
 

Here are some things that a spam rating web site had to say about SpamAssassin called Spamotomy. Spamotomy reviews anti-spam tools for use on home computers, enterprises and ISP level.

 

  
  Whether you run a Web hosting company or simply get your email access through one, being able to stop spam at the server definitely has its benefits. Not only do you keep all that marketing and semi-porn from getting anywhere near your personal computer, but you also save on all that bandwidth that junk mail so easily manages to eat up.  

SpamAssassin has matured quickly in the past two years thanks to the help of patches sent in from dozens of contributors. The latest version not only features a wider set of the heuristics that made the program so popular in the first place, but also supports DNS blacklists, collaborative spam tracking through the Vipul's Razor service, Bayesian learning, and automatic whitelisting. In short, it's got enough tricks up its sleeve to keep even the most persistent of spammers from getting by. 

All in all, SpamAssassin 2.55 is one of the most advanced anti-spam tools out there, and we recommend it to anyone who gets their email through a Unix-based server.