[barrkel]

Perhaps, instead, you should try using a better spam blocking system. Gmail's system works quite well.

I personally wouldn't touch Spamhaus with a ten foot pole. From everything I hear, they seem seriously biased towards incorrectly blacklisting IPs than letting a few bad ones through; more highly favouring false positives than false negatives in terms of identifying malice, in other words. Thing is, I believe most reasonable people prefer the reverse trade-off; they would rather get a little more spam than risk losing email.