Thunderbird Not Working with Office 365: Fix Issues

Quick Answer: Thunderbird Mail Not Working with Office 365

If Thunderbird is not working with Office 365, check and update IMAP settings, enable modern authentication, and generate an app password. You may also need to update Thunderbird to the latest version for proper OAuth2 support.

Common Reasons: Thunderbird Failed Work with Office 365 Emails

• Wrong IMAP or SMTP settings in Thunderbird.
• Basic authentication is disabled by Microsoft.
• Thunderbird version does not support OAuth2.
• Corrupt profile or mailbox configuration.
• Also, a poor internet connection or a firewall blocking.

Manually Fix Thunderbird Not Working with Office 365

You can solve this issue by correcting your email settings and enabling modern authentication. First, make sure Thunderbird is updated to the latest version. Then check your IMAP and SMTP settings, and enable OAuth2 for secure login. These manual fixes usually restore connection with Office 365 without needing extra tools. Here is how you can perform this:

Step 01: Update Thunderbird to the Latest Version

1. First, open Thunderbird → Go to Help → About Thunderbird.
2. After that, if an update is available, install it. 
3. Now, this ensures support for OAuth2 authentication.

Step 02: Check and Correct IMAP/SMTP Settings

1. Then, open Thunderbird → Account Settings → Server Settings.
2. Next, use the correct Office 365 settings:
   • IMAP Server: outlook.office365.com | Port: 993 | Security: SSL/TLS
   • SMTP Server: smtp.office365.com | Port: 587 | Security: STARTTLS

Step 03: Enable OAuth2 Authentication

1. Again, go to Thunderbird → Account Settings → Authentication Method.
2. Now, select OAuth2 for both incoming and outgoing servers.
3. Further, sign in with your Microsoft 365 credentials when prompted.

Step 04: Generate App Password (If MFA is Enabled)

1. Log in to your Office 365 account.
2. Go to My Account → Security Info → Add Method → App Password.
3. Afterwards, generate a new password and use it in Thunderbird instead of your regular one.

Step 05: Repair Profile to Fix Thunderbird Not Working with Office 365

1. Now, open Thunderbird → Go to Help → Troubleshooting Information.
2. Then, click the Repair Folder for Inbox or create a new profile to refresh the account.

Step 06: Check Firewall & Internet Connection

1. Ensure that your firewall is not blocking Thunderbird.
2. In the end, use a stable internet connection to avoid sync issues.

Alternative Method: Thunderbird Not Working with Office 365

If Thunderbird keeps showing errors, you can use a professional DRS Thudnerbird Backup Tool to access your Office 365 mailbox. This allows you to download all emails into formats like PST, EML, MBOX, and other formats. So you can open them on any email client. Advanced features with a simple interface, even a non-tech user can easily use it. Furthermore, you can migrate Mozilla Thunderbird to Gmail and other email clients.

Simple Steps to Access Office 365 Emails without Thunderbird

1. Initially, download & install the DRS Thunderbird Backup Tool.
2. Now, choose the Thunderbird Profile that you want to convert.
3. Then, preview and choose the emails to access in your O35 account.
4. After that, choose the Office 365 account from the available saving format.
5. Further, enter your Office 365 details, such as ID and Password, to Sign In.
6. Lastly, use advanced features/filters as per your needs. Click Convert.

Why Fixing Thunderbird Office 365 Issues is Important?

• Ensures uninterrupted email communication.
• Prevents loss of important messages.
• Improves security with modern authentication.
• Moreover, keeps Thunderbird running securely with Office 365.

Also Read: Migrate Thunderbird Emails to Google Workspace.

Conclusion

Thunderbird not working with Office 365 is a common issue after Microsoft disabled basic authentication. The fix is simple: update Thunderbird, use correct IMAP/SMTP settings, enable OAuth2, and generate an app password if MFA is enabled. If the issue persists, try using a professional IMAP Backup Tool to securely access your emails without downtime. In addition, download the demo version of this tool to understand its features and performance.

Frequently Asked Questions