your best bet, and to prove you are doing this legally, is to setup an e-mail server on your PC. YOUR pc then sends out mail and the mails come directly from YOUR ip address. That way anyone who managed to sneak into your opt in list without actually opting in can report you to your ISP and have your account deleted.
That way everyones happy, u get to spam the crap outta unsuspecting people and they get to have your internet account removed (if ur spamming illegally that is)
