I have a requirement to forward emails from a user in my domain (mycompany.com) to an external email Address (user@yahoo.com) I have setup up an external contact and then set the forward options to forward to that address using Active Directory users and computers > Exchange General > Delivery Options. The forwarding works fine for internal mails, but fails when trying to forward to an external address with the following message SMTP: 551 this is not a relay host mail must be to or from host domain. Now im guessing this is because @yahoo.com is not authoritive in my domain, so therefore unable to relay. Is this a way around this? I dont really want to allow the yahoo.com domain to relay through my exchange server. Im using Exchange 2003 Any help would be much appreciated, as this is doing my head in !! Kind Regards Adam Bird