Spam filter no longer working

Spam filter no longer working

My spam filter used to work perfectly, until yesterday. I've gotten about 15-20 spam emails both yesterday and so far today sent to my inbox that shouldn't have.  It is now catching spam about 50% of the time.  Has anyone else had this problem recently?

I haven't changed any settings and my spam filter IS enabled, so I don't understand why this is happening.  It's very annoying and I'd like to find out why and get it fixed.