All IDR does is restore the OS. If the machine is a database server, then you also need to recover the database. One of the reasons I refuse to even look at IDR. It saves you absolutely no time, because it just does everything you would do, but behind a wizard
The Exchange data cannot be backed up while Exchange server is running with a flat-file backup. As long as you have the Exchange Agent, and are backing up using that, you can recover the Exchange Stores and Public Folders