with upgrade, lost folders I filed emails into
With an upgrade to thunderbird, My inbox and trash folders remained, but other folders in which I file previous emails by subject matter disappeared. Several of the folder names were still there, but now empty. Other folders vanished, but did not reappear empty. How can I recover these? Assuming I can recover, how can I save these emails to another hard drive so they wouldn't be lost again?
Alla svar (1)
See http://kb.mozillazine.org/Disappearing_mail
To backup your Thunderbird profile: https://support.mozilla.org/en-US/kb/profiles-tb#w_backing-up-a-profile