I have had my domain “spoofed” in the past but nothing like what has just happened. I did report this problem to Tech Support, but I never heard anything about it yet as they have over 500 issues they are currently working on.
Here is what happened today! I received over 500 e-mail messages that had Undeliverable type of messages. I think someone is using my domain to relay spam! They have used an e-mail address that I don’t have! It was something like Hey17@mydomain.com. How do I stop this? My domain is probably on some sort of “spam” list somewhere now… How do I check and change that too?