You can remove mail domain aliases for ALL your mailboxes on the primary mail domain. But you cannot remove a mail domain alias for an individual mailbox.
To remove mail domain aliases for all your mailboxes on the primary mail domain, go to the E-mail resource page. In the Mail Control section choose the mail domain. The Mail Domain Aliases section will list all the current mail domain aliases for this mail domain:
Click the Delete icon next to the mail domain alias you would like to disable.
Article ID: 758, Created: March 15, 2011 at 2:21 PM, Modified: April 8, 2011 at 1:45 PM