[US Navy Vet]

...sigh...

[Da Coyote]

Gasp, I didn’t know they were still hiring Microsoft engineers.

[Red Badger]

If Thunderbird is giving you problems, there's always Wild Irish Rose..........

[donozark]

10.0.1- latest version of T-Bird/Firefox. What version are running?

[backwoods-engineer]

Been using Thunderbird since version 1.0. NEVER totally lost my email. Are you sure it didn’t lose the location of the email? Get a friendly computer geek to give you a hand. I bet your emails are still there.

[Mount Athos]

http://kb.mozillazine.org/Disappearing_mail

[oh8eleven]

Your email isn't lost.
Try searching "recovering lost thunderbird email" and you'll find more than a few solutions.

[Mr Fuji]

Thunderbird email crashes on my wife 1-2 times a day. She has a lot of “archived” emails too. I’ve been pulling my hair out to figure this problem out.

[WHATNEXT?]

I haven’t been able to send or reply to emails for a long time. So, had to go to server and get mail there, and now I can send email and reply. What a hassle for a non geek!

I’m told it makes no sense to continue with Thunderbird or Firefox for that matter and I should go to Windows.

[VeniVidiVici]

FireFox has started to blow it seems now they’ve changed their patch cycle

[glorgau]

Don’t use Thunderbird. For myself, I don’t like how they presume that directory servers support keep-alive connections.

[Freedom_Is_Not_Free]

My version 9.0.1 is fine.

[zeugma]

Why not just restore from backups?

If you don't back up your computer, then it must not be terribly important. If you use firefox, it's a good idea to back up your bookmarks as well. I have bookmarks that are over 20 years old, because I learned long ago that backups are important.