Do you know every passwords of the accounts you set? You could simply reinstall thunderbird (also make sure that there is no remaning properties that would put everything back to the same state) )and install it again. It'll take you few minutes to link your accounts again, but that's still better than not beeing able to access them, right?

Forget the previous suggestion. Reinstalling Thunderbird will do nothing for you. The thunderbird program is separate from the user data. If you reinstall the program it will find your old profile and your will be right back where you started.

The only password in Thunderbird is the Master Password and it is optional. It is most likely asking for your email password. Email passwords are administered with your provider. Contact them to reset a forgotten password. Most providers have a link on their email help page to do this.

For some reason it seems that the email for mozilla thunderbird is now working. Do not hold your breath, but I received your two emails and was able to send an email out. I will let you know if it does not keep working or if I have to uninstall and install the program. Keep your fingers crossed.

Reinstalling the program will keep you busy for a little while but it rarely fixes any problems. That first suggestion was poor advice.

As i said, also make sure that there is no remaning properties that would put everything back to the same state = userdata. Thus in case of master password', reinstalling will fix it. This is a proper answer.

@Airmail browsing your answers on this forum show that you like to trash talk every time you're not the one replying first or put as best answer. I apologize your highness for disturbing your forum. I won't reply to anyone as your amazing knowledge allows you to judge people.

Thanks for another useless answer Remibloch.