Thunderbird will not reinstall clean

It began with thunderbird would not send messages. It can receive messages and the password is correct. I have checked the server settings, reset the passwords, deleted passwords, changed passwords, and gone through the entire FAQ several time. I even removed the mail account and set it up new. So I have now resorted to backing up the profile and then removing Thunderbird from the computer to see if a clean install and set up will fix the problem. Now when I reinstall thunderbird it automatically migrates the old profile into the thunderbird install so there is no way for me to start from scratch. Is there a fix for the email that will not send? I am out of ideas!