You need to tell us a bit more. What Operating system are you using - eg: Windows 11, MAC, Linux? What version of Thunderbird are you using ? Not sure - in Thunderbird - 'Help' > 'About Thunderbird' It will tell you the current version. eg: 140.8.0esr or perhaps 148.0.0 Your mail account downloads emails from the server, but what server are you using ? For example: gmail, btinternet, comcast, yahoo, outlook, AT&T, AOL ? In your email address what comes after the '@' sign ? It would help if you could provide the following information. In Thunderbird * Help > Troubleshooting Information * scroll down to the 'Mail and News Accounts' section * Copy all the text in that area and then paste it into a Reply Box in this forum question. '''re :new method of sign in message''' It's possible you have never been entering a password because you set up Thunderbird to remember your password and auto use it to download / send emails. If you had logged onto your webmail account via a browser and changed/modified that password then you would to update the stored password in Thunderbird. Did you logon to your webmail account and modify/update your password ? Are you seeing a small window which asks you to enter a password, with buttons 'Retry', 'Enter new Password' and 'Cancel' ? Does the small pop up window say anything at the top such as: Enter credentials for email address on outlook.office365.com, then a line that starts with https and below that the word 'Microsoft' followed by 'Enter Password' ? You may have been asked in Thunderbird to log in your Yahoo, ATT or AOL accounts, or seen a notice with the title 'Upcoming Account Change'. Did you get something like that ? Describe what you see - tell us word for word what you see OR better still upload an image in this forum using the Add images 'Browse' button located just below the 'Post a Reply' text box.