HOW TO FIX “LOGIN TO SERVER IMAP GMAIL COM FAILED” ISSUES ON THUNDERBIRD

While I was setting up my Gmail account, I came up with the issue above. My Thunderbird account was getting repeated email error messages in my email client from an email server. Sometimes this can be caused by issues with the server, or perhaps the connection, or because some configuration has changed or simply because you have not set up your email properly. Then I realized that my notification in my Gmail account access for apps was turned off. After turn on notification my Gmail account in Thunderbird start working again.

If its still doesn't work, then please try to visit accounts.google.com/DisplayUnlockCaptcha to unlock the captcha (as suggested by rncp Youtuber on a comment below).

Hope these information will help you to solve the issue with your Thunderbird.