The big question always associated with backups is, "What should we back up?"
There are many things that contribute to our final decision. Of course, we want to back up our server's configuration because it is essential to our server's functionality. But we also want to back up the users' data because it is a valuable asset to our business. Is there a company policy that says people may use e-mail for private communication? If there is, should we back up those messages as well?
We should only back up what we need to restore the system to a functional state. This saves space on the backup media and shortens the time required to perform a backup and restore if necessary.
After all, the space on any backup media is limited and thus precious. ...