Receiving someone else's mail

Hi everyone,

I have s strange thing happening at the moment, I am getting mail destined for someone else. I believe it is coming to me due to the postmaster email address.

The thing is, I do not know why these messages are ending up at the postmaster email address, as the address the emails are sent to exists, and I can't see any reason why they wouldn't be delivered.

Is there some way I can check the mail routing, to see why I'm getting these emails?