Ask for another solution
I've used ask (Active Spam Killer) for exactly year. It has let through 2 spams in that time, while I get 15-30 per day.
Advantages: people that you care about can easily get through. Very small percentage of spams get through. White list is easy to set-up.
Disadvantages: takes too much disk space in it's queue-it saves the spam for too long by default and should probably compress/decompress it.
Seeming disadvantage that I haven't encountered: it relies on replies which should make spammers think your address is real and increase the amount of spam you get. I haven't found this to be the case.
All that said I'm happy with it.