I've noticed after upgrading from 3.0.1 to 3.1.0 RHEL4_GA version that I'm getting a lot more Spam in user inboxes that aren't being filtered into the Junk box.

I've checked what I can think of in the Admin Console, and SpamAssassin is enabled, and I have restarted Zimbra. What can I check to make sure everything is working fine?