I have 2 users in 2 separate organizations who are experiencing phantom email deletion. Their items do not go to deleted items. They are removed from the mailbox entirely and show under "Recover Deleted Items". These deleted items, however, are not recoverable. If you elect to recover an item it will disappear from the Recover Deleted Items window, never show in the Inbox, and will almost immediately show back up in Recover Deleted Items. Both users (again, different companies) are claiming to have no part in the deletion.