Your feed-back made us feel more and more convinced that we had an IP hijacker within our network who had stolen your identity. This is why our Abuse Team asked you to use our Forensic Tool, to be found in you personal Control Center, to protect your server from further abuse and to alert you of the situation.
As you probably are aware of, we take pride in providing you with the real story when incidents happen – the facts, the causes, the solutions and the recommendations. That’s how we do business.
This is what happened
A skilled spammer, unfortunately a customer of ours, designed fake mailheaders in a number of ways including spoofing your IP address and using third party ‘Return-Path’ and/or ‘From’ addresses – often @gmail.com addresses. The real server with the abused IP (belonging to you) gave the target MTA a valid response and the third party ‘Return-Path’ and/or ‘From’ addresses received the bounce, if any. Mails from owners of these ‘From’ addresses started complaining Jan. 17-18 2006 increasing in numbers over the days that followed. So did spam complaints on your IP!