Godaddy email has moved to outlook.office365. com. After months of a single mention about deprecating Simple Auth, they cutover to OAuth2 without notice (approximately 5/18/23 7PM ET). Of course this broke any POP3/IMAP configs including K-9 Mail, without anything other than a generic “Login/Password Failed” message.
Godaddy support was worthless - but I found a hint here on K-9 mail forum. (Which also helped with Thunderbird).
Don’t know how to file a Feature Request/Bug report for K-9 mail. If an email address has the outlook.office365. com domain, the ability to configure OAuth2 without creating a new account would be helpful.
FYI: Deprecation of Basic authentication in Exchange Online | Microsoft Learn