Just in case someone might find this useful …
I recently had something bad happen to me. I use Thunderbird (on Windows Vista) as my email client. I asked Thunderbird to compact my email files, and it wiped out a bunch of my email messages. (I think that one of my email files must have been corrupt, and when I compacted it, the compaction process wiped out messages that should not have been wiped out.)
You can recover deleted email messages … but not after the email file has been compacted. So the messages were not recoverable. Bummer.
The upside is that this nasty incident led me to learn some things.
One thing that I learned was that the disk backup utility that I was using at the time did NOT backup my email files. The email files were stored in a directory called AppData, and the AppData directory is a “hidden” directory. So the backup utility didn’t see the AppData directory, and didn’t back it up. So I had no backup of the deleted messages.
Learning that led me to investigate ways to backup my email files, and I found this: Five ways to keep your emails backed up
For backing up Thunderbird files, it recommends MozBackup as being fast, free and easy to use. So I tried MozBackup, and those claims seem to be true.
Now I’m evaluating different disk backup options.
The take-away here is that you need to pay special attention to backing up your email files. So if you’re not backing up your email files, take a look at Five ways to keep your emails backed up (and read the comments, which are useful) or google something like “email backup”.
[Note that this applies only if you are using an email client such as Thunderbird, Outlook, Outlook Express, etc. If you don't use an email client, and do all of your email work through a Web interface to your Internet Service Provider, then this is not an issue.]