To setup Gmail in Thunderbird on Mac, start by opening Thunderbird from your Applications menu. If you haven’t yet downloaded Thunderbird for Mac, you can download it from the Mozilla Thunderbird Website.
When you are launching Thunderbird for the first time, you will be presented with an offer to signup for a free email address through gandi.net just click on ‘Skip this and use my existing email‘ to proceed with getting your Gmail setup in Thunderbird.
Thunderbird will automatically configure your account once you provide Your Name, Gmail email address and Gmail email password. By default, Thunderbird will set your account up using IMAP which is the most modern way to access your email and best if you are accessing from multiple devices since all of your emails will remain on the server. If you prefer the old school POP access be sure to check that option before clicking ‘Done‘.
Once you have clicked ‘Done‘ you must provide Google authorization allowing Thunderbird the ability to read, send, delete and manage your email.
That’s it! You are now ready to use your Gmail email account with Thunderbird on Mac.