See
https://www.thunderbird.net/en-US/thunderbird/all/ if you want a 64-bit version. However, it doesn't make a difference whether you use a 32 or 64 bit version. I suspect the real problem is that AT&T has so many different subsidiaries (and sometimes lets you choose between multiple email providers) its tough figuring out what setup settings to use. Bellsouth.net is a legacy email domain (like sbcglobal.net and a bunch of others)
Lately AT&T seem to be using yahoo as their email provider - see
https://forums.att.com/conversations/at ... f606ad5b96
Some email providers require you to generate a app password (they might call it a security key) via their web site that you have to use instead of the normal password if you use a email client. I don't know if that applies in your case.
"
It Won't install bellsouth.net emails"
I think you mean that you have problems adding an account for bellsouth.net using the new account wizard.
What error message do you get?
ISPs are poor email providers since they view it as just a cost center. If its a not a big hassle notifying people that you changed your email address you might want to consider using a Gmail account instead. You could probably log into your bellsouth webmail with a browser and configure it to automatically forward all email to your new address, to ease the transition. You can also configure your Gmail webmail to automatically fetch mail from another email provider's email address and merge that email into your gmail webmail inbox. If you do that Thunderbird will see the merged email too.
