Answer: In Exchange Server 2010 we can easily Add, Edit and Remove User’s email address.
To Add, Remove Or Edit a User Email Address In Exchange Server 2010 Follow the steps below:
Open EMC and go to the User mailbox -> Double Click on the mailbox and Go to Email Addresses Tab.
In the Email Addresses Tab use the middle buttons to Add, Edit and Remove email address.
This is the Add email option.
This is the Edit