wheel - 3:28 pm on Feb 1, 2011 (gmt 0)
I was blacklisted by comcast years ago for no other reason than I did email forwarding for hosting clients - bounced all their emails to their comcast account.
Call, they'd whitelist me. A week later, blacklisted again. Call, they'd whitelist me. A week later...etc.
I eventually just told clients to use a different internet service provider. Sorry, don't have any suggestions other than to try and call them on the phone.