Like so many other people, I use Google Mail (Gmail) everyday on my cell phone, tablet, and computers. In addition, the college where I teach uses Gmail for  student email accounts. I like to have Gmail setup in Mozilla Thunderbird on my computers (Windows 10 and CentOS8) so I have quick access to answer student emails and other electronic correspondence. 

Configuring access to Gmail has gotten more difficult in recent history due to stricter security standards required by Google.  I was not able to find an article on the Internet that provided directions on how to add a Gmail account to Thunderbird. The automatic setup provided in Thunderbird only worked for IMAP and not SMTP. After some research and tinkering with the setup, I found the right configuration settings that worked for my computers and Gmail accounts. I hope these notes help others in the same situation.

Mozilla Thunderbird Gmail Setup
As of June 7, 2021

The following configuration settings were successful in setting up the current version of Mozilla Thunderbird as the desktop Gmail client in Windows 10 Professional and Windows 10 Enterprise.

Mozilla Thunderbird 78.11.0 (64-bit)

IMAP Settings
Server: imap.gmail.com
Port: 993
User Name: yourusername@gmail.com
Connection security: SSL/TLS
Authentication method: OAuth2

SMTP Settings
Server: smtp.gmail.com
Port: 587
User Name: yourusername@gmail.com
Connection security: STARTTLS
Authentication method: OAuth2

The “OAuth2” authentication method was not on the selection list when initially setting up my Gmail accounts in Thunderbird using the manual configuration option. I choose “Normal Password” which failed but under “Advanced Config” in Thunderbird’s manual account setup I was able to force saving the account. Then I edited the account to use “OAuth2” for both IMAP and SMTP.

The first time accessing the Gmail inbox in Thunderbird, I was taken to a Gmail authentication screen in my browser where I entered my Gmail username and password successfully. The the Thunderbird inbox populated with the email on the Gmail IMAP server.

This configuration has worked as expected. There has been no evidence of any instability.

I was unable to use the Google Contacts or the gContactSync extensions to synchronize  Google Contacts with Thunderbird’s address book because the current version of Thunderbird was not supported by the available extensions. Hopefully these extensions will be updated soon. I had to do a manual export/import including some heavy editing of the contacts.csv file. This article might be helpful if you are importing contacts to Thunderbird:  https://www.nucleustechnologies.com/blog/synchronize-thunderbird-address-book-with-gmail-contacts/.

Please post a comment if you have success with these settings or if you have other suggestions on how to use Gmail on Thunderbird.