I have an email address (email@example.com) that doesn't forward to another inbox besides the one created for it (m123).
I can send and receive emails just fine. The problem is when someone sends me an email, which I get, the sender gets a message from the Postfix program at murdock.dreamhost.com:
firstname.lastname@example.org: unkown user: "987654"
[ Part 2: "Delivery error report" ]
Reporting-MTA: dns; murdock.dreamhost.com
Final-Recipient: rfc822; email@example.com
Diagnostic-Code: X-Postfix; unkown user: "987654"
The numbers aren't 987654, but it is a number that I don't recognize for anything.