This feature is available in Enterprise and Ultimate editions.
Unarchiving a message allows you to retrieve a message that was previously archived and redisplays it in your My Inbox.
From the main menu, select My Home > My Views > My Inbox.
Click inside the Filter field, and then select Show Archived Messages. All archived messages will display in
Select the message(s) you want to unarchive, and then select Unarchive from the action menu.