No Mail is Good News?

I think when I retrained my spam filter I did a bit too good of a job. I used to know mail was working and things were going properly because of the few spam emails that slipped through and the costant, once every 30 minute error messages from my buggered up install of ipaudit. Now neither occurs and I sometimes wonder if my mail is broken when I don't get at least a couple of useless, delete-them-immediately messages between each time I check my mail.