Let me start with a brief disclaimer I’m not a formal Exchange administrator but I’ve been using it enough years to get my head around it and basically understand how to get it to do what needs to be done.
A fairly common task I have performed in the past is to redirect a former employee’s email to their replacement or senior and in the past I have achieved this by disabling the old account and adding the old user’s address to the list of addresses of the new user. I never felt happy with this solution and it always left me feeling a little bit dirty.
I’ve since found a much better solution after some very quick googling and I’m posting it here as a reminder:
From Active Directory Users and Computers find the old user, right-click and select properites. On the Exchange General tab select Delivery Options. In the Forwarding Address box select “Forward to:” and then enter another Active Directory user or contact by clicking “Modify…”. Finally click OK on all open dialogues and you’re done.