Saved Passwords in Settings/Privacy & Security contains passwords and secure mail keys. I recommend removing all entries for the account in Saved Passwords, restarting TB, entering the secure mail key when asked for a password, and checking the box to store it in Saved Passwords. You might have to also enter the key the first time a message is sent.

Thanks for the suggestion but that did not work for me. Perhaps deleting the Bellsouth selection in Thunderbird and reinstall or is that an option? Mike

If the account is IMAP, removing the account and adding it back will download the messages on the server (if it connects). If it's a POP account, copy the existing folders to Local Folders before removing/re-adding, as this will make it easier to restore existing mail. What errors to you get? If you have a non-Windows Security AV app like Avast, eSET, Norton etc. it could be blocking the connection.

I think if you type long enough you eventually strike a combo of where it will work. I found if I send a message on Bellsouth to myself at my Comcast account, and end up entering the password, ATT Secure Key, it is now letting me send message on Bellsouth to other people. No clue what that has to do with anything. Like 100 monkeys typing long enough they will write a novel. I'll see how long this works. Thanks for the help. Mike