Outlook 03 & Excessive Junk Mail

Besides changing the Junk Mail Filter to High and creating rules, is there any easy way to stop excessive junk mail in Outlook 03? I have a network at a hospital that I maintain, about 5 of the employees recieve about 300+ emails on a daily basis and I need a simple way to help this. I have changed the filter to High but they are still getting them, I hate to create rules because they never know who they will get an email from.

 

I guess you have more experience than me, but I Am using Spamfighter and I Am really happy with the work that does it for me!!!