Example of Mozilla Thunderbird IMAP settings（OAuth）

Introduction

Contents of this manual are "Operation Confirmation" under the following environment.
Software: Thunderbird(ver 147.0.2)
OS: Windows11 Pro 25H2 (64bit)
Please perform the following procedure. When setting up, you will need to log in to keio.jp. Please check your Keio ID and password in advance.

Procedure: setting under Mozilla Thunderbird

1. Start Mozilla Thunderbird.
2. Click [≡]Icon → [New Account]
   
   
   
3. Click [Email] and advance to next step.
   
   
   
4. Configure the [Add Email Address] settings. Enter the following information as reference information:
   

   Full name	Type your name (This information will be used for your sender information).
   Email address	Your Keio ID (Example: keio-taro@keio.jp). Precaution: enter including state after @mark.

   After entering the information, click [MANUAL CONFIGURATION].
   
   
   
   
5. Configure the [Incoming server settings]. Perform settings referring to the following information:
   

   Protocol	IMAP
   Hostname	imap.gmail.com
   Port	993
   Connection security	SSL/TLS
   Authentication method	Oauth2
   Username	Username: Your Keio ID (Example: keio-taro@keio.jp). Precaution: enter including state after @mark.

   After entering the information, click [Continue].
   
   
   
   
6. Configure the [Outgoing server settings]. Perform settings referring to the following information:
   

   Protocol	SMTP
   Hostname	smtp.gmail.com
   Port	465
   Connection security	SSL/TLS
   Authentication method	Oauth2
   Username	Your Keio ID (Example: keio-taro@keio.jp). Precaution: enter including state after @mark.

   After entering the information, click [Test].
   
   
   
   
7. If the message "The following settings were found by probing the given server:" appears at the top of the screen, click [Continue].
   
   
8. The Google login screen will be displayed. Confirm that your Keio ID (e.g. keio-taro@keio.jp) is entered and click [Next].
   
   
   
9. The keio.jp authentication screen will be displayed, so please log in.
10. You will be requested to access your Google account, so click [Allow].
    
11. The "Sync your calendars and address books" screen will appear. Click [Continue].
    
12. If "Email account connected successfully" is displayed, the connection setup is complete. Click [Finish] to finish the process.
    

Revision History

2020/02/27: First created

2022/08/17: Software and OS version updates

2026/03/17: Software and OS version updates. Changed configuration steps and images due to the addition of the "Account Hub" feature.