Have you tried this form?

http://www.comcastsupport.com/Forms/NET/blockedprovider.asp

Frank

From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] On Behalf Of Raymond L. Corbin
Sent: Tuesday, October 09, 2007 4:30 PM
To: nanog@merit.edu
Subject: Any Comcast Mail/Sysadmins?

Hey,

I'm having a few deliverability issues to a few comcast mail gateways. Is there any comcast mail/sys admins here or anyone who can get me in contact with them off list? It would be greately appreciated.

Thanks for the help!

-Ray