Backup Thunderbird's Email
As opposed to backing up Thunderbird manually, there are a number of programs which will do this for you. My experience with them as been mixed, but some do the job quite nicely once properly configured.
Picking the right backup utility is usually pretty difficult, as many of them seem to be similar to one another and the only time when they are actually put to use is during some sort of emergency. Your best bet is to actually choose a few and try them to see if they suit your needs.
This one of the best Mozilla back up programs. It is freeware and supports Firefox, Thunderbird, the Mozilla Suite, SeaMonkey, and Netscape. It is easy to use and install, but support is limited and there is no Linux version available yet.
This is commercial software (available for $14.95, or $19.95 for Pro version) which backs up Thunderbird's email. The company also make utilities for IE, Palm, Eudora, and so on. The features of this program include an easy-to-use Wizard interface, automatic backups using Windows Task Scheduler, backups to ZIP files, password protection, and a restoration program restoration program. The Pro version also can writes backups to CD/DVD.
There are a number of other options out there but these two both work well. Doing the task manually is very easy, but a tool can be useful for extras, like having the backup done automatically or also backing up extensions. Either way this is something which is very important to do and can be easily overlooked if you are not in a data-protecting mindset.