I have a user on an SBS 2003 box that cannot receive mail. The error is below;
Remote host said: 550 5.1.1 <firstname.lastname@example.org>: Recipient address rejected: User unknown in relay recipient table
The user has been recreated 3 times, twice with a default user template and once with a mobile user template. They can send fine and can access the RWW and OWA with no problem. Sending mail to the outside is okay but when replying or creating a new message to the user one receives the previous error message.
Under the Exchange System manager his address has not been targeted by any receipient policies. Under the SMTP virtual server his name/mailbox has not been granted or denied any special permissions.