Thunderbird Question

[Braedley]

I've been using Thunderbird since October or so, and, for various reasons, had to reformat my hard drive a couple of times. Each time, I lost all my mail because I didn't leave it on the server. Changing the directory to which it saves the email only means that all the mail in an inbox folder gets saved to one file on the hard drive, and can't easily be recovered after a reinstall. Is there a quick and easy way to have Thunderbird automatically back up (or save) new emails to another partition or drive, and have them accesible to future installs?