Configure Thunderbird for Office 365

This document describes how to configure modern authentication with new Thunderbird versions (ver. 78 or above which supports OAuth2 modern authentication). Please note that Thunderbird version 78.0 is only offered as direct download from thunderbird.net and not as an upgrade from Thunderbird version 68 or earlier that means the previous settings cannot be preserved or imported to this version.

Configure Thunderbird for Office 365

  1. Launch Thunderbird.
  2. Righ click Local Folders and select Settings
  3. Select Add Mail Account... under Account Actions
  4. Enter Your name and Email address and click Configure manually...
  5. Enter the following parameters:

    IMAP Server: outlook.office365.com
    Port: 993
    SSL: SSL/TLS

    SMTP Server: smtp.office365.com
    Port: 587
    SSL: STARTTLS

     
  6. Click Advanced config and then Yes to proceed with the required configuration
  7. Select Server Settings under your email and select OAuth2 under Authenticaiton Method
  8. Select Outgoing Settings (SMTP) and then click Edit
  9. Enter Description of the server (e.g. Office 365) and select OAuth2 under Authenticaiton Method
  10. Close the account settings tab
  11. When you attempt to view your inbox, you will be redirected to authenticate through DUO.
  12. After the Duo authenticating, the setup is complete. Email data will take some time to sync. Please wait patiently, especially for larger mailboxes. 
  13. Complete the following additional setup steps before start to use Thunderbird.

Additional setup steps

  1. Right-click on your email account and select Subscribe... from the drop-down menu
  2. Place a check-mark within the box next to each of these folders: Drafts,  Deleted Items and Sent Items if they have not been checked.
  3. Click the Subscribe button.
  4. Click OK
  5. Right-click on your email account and select Settings... from the drop-down menu.
  6. Under your email account, select Server Settings, select the Deleted Items folder under When I delete a message.
  7. Under your email account, select Copies and Folders.
    • Within When sending messages, automatically, select the Send Items folder
    • Make sure Drafts folder is selected under Drafts and Templates
  8. Close the Account Settings tab (changes should be auto saved)
  9. Restart Thunderbird