We currently host email for our domain @gfreview.com on an Exchange 2003 server. We are trying to add a domain alias @i.gfreview.com. We have added the MX record for the i.gfreview.com domain to point to our server, and updated the Default Recipient Policy to include @i.gfreview.com (as well as updated all users, "This Exchange Organization is responsible for all mail delivery to this address" is checked, and the domain is checked in the recipient policy). When sending an email to @i.gfreview.com however, we get a bounced email back from our Exchange server that it was "Unable to Relay".
Any ideas?