What items can be backed up?
You can back up user mailboxes and shared mailboxes. Group mailboxes and archive mailboxes (In-Place Archive) cannot be backed up.
What items can be recovered?
The following items can be recovered from a mailbox backup:
You can use search to locate the items.
When a mailbox is recovered to an existing mailbox, the existing items with matching IDs are overwritten.
Recovery of mailbox items does not overwrite anything. Instead, the full path to a mailbox item is recreated in the target folder.