One thing I can suggest is read my tutorial on fighting back against spammers. But in order for that not to be a pain in the ass is to catch it early. If your already getting hundreds of spam, don't bother cause it will be a pain in the ass .

My tutorial isn't the greatest written tutorial but the info will do you well. You can get to the tutorial by clicking the "1" next to the "Security Tutorials Written:" in the left hand side of this post.