Postfix problem?

I have an email address ( 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 unkown user: “987654”

[ Part 2: “Delivery error report” ]
Reporting-MTA: dns;
Arrival-Date: …

Final-Recipient: rfc822;
Action: failed
Status: 5.0.0
Diagnostic-Code: X-Postfix; unkown user: “987654”

The numbers aren’t 987654, but it is a number that I don’t recognize for anything.

Yes… this was another bug. I was going to send a preemptive message, but looks like someone beat me to the post. Should be fixed now.

It is not fixed, I am still having the same issue.