I migrated my installation from an old hard drive, I have all of my old accounts and email, but cannot get or send new email, never get asked for password.
My old laptop died, so I migrated my Thunderbird to a new one. All of my old accounts and email is there, but I cannot get new email or send new email. I never get asked for a password, nor do I see anywhere that I can enter them. I looked at the saved password button in Tools/Options/Security/Passwords, but there are none listed. I even tried changing the password on my email account at the server, but Thunderbird still doesn't ask me for the new one.
Opaite Mbohovái (1)
Try with your OS in its Safe Mode. You may have security software preventing Thunderbird from connecting to the email server. It won't ask for a password until it has actually engaged with the server and started a login process.