You can use Disk Space Monitor by Netwrix, the standard version is free as well and works perfectly, read up on and, you can set your criteria and alerts will be send to you once the criteria is met:
Actually, you need a third part software program to automatically alert you through email when the hard disk drive is full. However, I don’t really personally recommend to wait for your hard disk drive to have no space. Remember that full hard disk drive could cause crashes or unstable computer system. It is better to purchase new hard disk drive when the other drive is full.