You have a user with an Exchange account and want to add additional email addresses.
This is done using the Exchange Management Console.
- Log into the Exchange 2010 server.
- Start the Exchange Management Console.
- Click on Microsoft Exchange->Microsoft Exchange On-Premises->Recipient Configuration->Mailbox.
- Right-click the mailbox to update and click Properties.
- Click on the Email Addresses tab.
- Click on Add.
- Add the email address and click Ok.
- You will return to the main window. Click Ok.
Be sure to test the new email alias by emailing it and confirming it arrives at its destination. Quite often this will fail because a site is using a hosted spam filtering solution and that needs to be updated with the new email address as well.