The Dumpster. In Exchange 2010 we introduce the new Dumpster 2.0. This is a completely different Dumpster than what we’ve had in the past.
An end user can do a soft delete or a hard delete on a message. The soft delete is when the item has been deleted from the deleted items folder – this item is placed in the dumpster. The hard delete is when an item has been marked for purge out of the store. There is also a hard delete via Outlook when a user uses Shift-Delete and this places the item directly in the dumpster bypassing the deleted items folder.
To help reduce the burden for the administrator most of my customers change the default from 14 days to 30 days and provide guidance for users to check the deleted items folder to recover mail vs. going to tape to recover an email.
The Exchange team has a great article that describes the new Dumpster in detail and how Litigation hold and single item recovery are handled in Dumpster 2.0. The article is linked here for your consumption.