Comm100 is pretty expensive as far as I know. You should use a service to clean out your list, like ListWise HQ. Since this is a black hat thread, I'll go and say that there are lots of esps out there that give out free accounts, or pretty cheap low volume accounts(10K contacts for like $30). Just setup different accounts and go through the account setup. You can mail it there, download the bounces really fast and watch them close your account the next day. At least your list will be clean.