You will need to purchase a 3rd party program or appliance to stop spam. there are many to choose from, we use CA’s Secure content manager,, but like I said all the major Antivrus companies have their own products. there are even services out there that will filter your mail for spam. I would recommend that what ever solution you go with, do not get one that runs on the mailserver itself.. the scanning of all your mail for spam will put a great deal of stress on your server and bog down your email.. especially during heavy spam cycles like just before a holiday. I would recommend a turnkey appliance or or a software solution that runs on its on server.