Comcast SMTP server is blacklisted

76.96.107.72 (omta02.potomac.co.businessclass.comcast.net.) the recommended SMTP server for business customers are blacklisted by NiX Spam run by a German ISP. 

Could someone from Comcast support please visit their Web site and fill in the form requesting for unblock.
http://www.dnsbl.manitu.net/