I'm trying to understand Exchange 2003. So from what I can understand by googling is that when a large mailbox is deleted, lets say 10GB, it does not free up space on the hard drive. Instead it adds 10GB of white space in the database. Also if I understand correctly an offline defrag must be done to reclaim this empty space, which it does by creating a new database and copying over the old. Will it not free up the space automatically? Is there any risk to doing this? As far as backup goes, does Exhange handle backup itself or does it need to be done by a 3rd party program? thanks.