Don't mess with the existing account, create a new account for the new server.

It still tries to use the old outgoing server. This is some pretty unflexable software. I am about ready to upgrade to something better if it can't be changed.

Post a screen shot of what you changed.

I would like to completely uninstall and then reinstall to start over. Can that be done? If not, why not?

I used the MS uninstall feature, then reinstalled. Everything came right back including all the fuckups. That means nothing was uninstalled. I want this software OFF my computer. Can anyone tell me how to do that without wiping the whole hard drive?

I used the MS uninstall feature, then reinstalled. Everything came right back including all the fuckups. That means nothing was uninstalled. I want this software OFF my computer. Can anyone tell me how to do that without wiping the whole hard drive?

Do you want to make it work or simply remove it because you don't understand it. Your comments so far express frustration and a complete lack of understanding.

You removed the application. You reinstalled it and it found and used your existing profile. That is working exactly as it is designed to work. Most folk would be devastated if their address data was that easy to loose.

Thunderbird has a profile manager for resetting your profile to a new one. See https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-thunderbird-profiles

Thunderbird also uses an outgoing server (SMTP) to send mail, and the entry for those is in account settings. This facilitates the use of different outgoing servers per identity and for this reason there is an entry in the from list for each outgoing server configures to an identity. The link is outgoing server in in the account settings as shown here https://support.mozilla.org/en-US/kb/configuration-options-accounts#w_account-settings-panel

Wayne asked you to post a screen shot, because we have no idea how you are identifying the server or even if you setting are sane. Are you entering ip addresses in the server name? or are you using some form of local DNS server? Or are you running the server software on the local machine and using the loopback address to point to it, or is the network address controlled through a hosts file.

You asked for assistance and so far have supplied very little information from which someone could make guesses to help you, let alone make read suggestions based in facts. As I have said above there are more questions than answers in my mind after reading this.

If you just want rid of it. Uninstall it and then using the windows run command (windows key + R) type %appdata% and delete the Thunderbird folder that is shown when windows file explorer opens to remove all profiles.

There are many things I dislike about Thunderbird, but I am struggling to find a suitable replacement. Certainly nothing free and I am down to one or two paid that I think might do the job. But I have not had time to properly evaluate them. But upgrading to something else as you so quaintly put it is not as easy as it sounds if your needs are more than basic. Google, outlook, gmx, yahoo and others web pages will suffice if your needs a basic so basic mail software is just not needed.