I have hot-swapped tape drives without any trouble, though I honestly don't know if you are supposed to or not. Can't remember the exact procedure to back up MMail, but you can find it in the menus. If you can't find it, let me know and next time I visit our PBX, I'll log in and write down the exact steps. By the way, you don't necessarily need to use the exact same tape drive. In fact, I found an old IBM SLR drive when our tape drive power supply died. Works fine and it was dirt cheap!