We have an exchange server running on one of our domains.
Some of the users require their mail forwarding out to an external account. We just use custom recipients to do this.
However, although mail from other users on the same server gets forwarded, mail sent from outside of that mail server does not.
This also fails to forward when rules are applied to the users mailbox.
In both instances there are no returned mails.
Server is Exchange 5.5 SP3.