Quick Solution to Fix Thunderbird Not Working with Office 365

Reasons Why Thunderbird Failed to Connect to Office 365

Below are the top reasons why Thunderbird often doesn’t configure with O365:

• Microsoft disabled basic authentication and enforced OAuth 2.0
• Due to incorrect incoming (IMAP) and outgoing (SMTP) settings
• Access blockers are caused by the default security settings 
• Conditional authentication and access policies 
• Limitations of the shared mailboxes may be a reason 
• Network or firewall blockers due to outdated Thunderbird 
• Temporary server or internet network issues are a cause too 

Multiple Ways to Fix Thunderbird Not Working with Office 365

Any user can try the following basic and advanced solutions to fix the connectivity issue between Mozilla Thunderbird and Office 365. But remember, there are some limits to the manual methods. 

Manual Fix Thunderbird Not Working with Microsoft 365

The different methods for free fix are mentioned as follows: 

Way 1: Implementing Correct Server and Authentication Settings 

It is very necessary to use OAuth 2.0 as the authentication model and input the correct server details for the connection. Below are the correct details and the steps to set up OAuth. These are: 

1. Incoming Server Details (IMAP)

2. Outgoing Server Details (SMTP)

3. Steps to set up OAuth authentication:

• Within Thunderbird, from the More menu, click Account Settings. 
• There, in the Server Settings, browse Outgoing Server, and click Edit.
• Next, under Authentication Mode, choose OAuth2.
• Check other details, exit and restart Thunderbird, and try connecting with Office 365. 

Way 2: Fix Thunderbird Not Working with Office 365 in M365

Another way is to enable IMAP and SMTP protocols in both Office 365 and Thunderbird for connectivity. Steps are:

1. Sign in to your Office 365 account and go to its Settings. 
2. From there, click on Mail and then tap Sync Email. 
3. At last, ensure that both IMAP and SMTP are enabled there. 

Way 3: Updating Thunderbird and Office 365 to Latest Versions 

1. In Thunderbird, go to Help and check for Updates. 
2. If any update is available, complete it. 
3. Similarly, look for any Office 365 updates and proceed with their completion. 

Way 4: Reconfigure Office 365 Account in Thunderbird 

1. Initially, run Thunderbird and click on the O365 email address. 
2. Remove it, and then under Email Accounts, choose to setup a account. 
3. Further, enter Office 365 username and password and choose to setup account manually. 
4. Finally, enter the correct credentials as provided above in 1st way and tap Done to connect. 

Shortcomings of the Manual Method 

• It is very time-consuming and complex, especially for non-tech or novice users.
• User cannot depend on any one free solution and may need to try them all out. 
• High risk of data loss prevails in these methods without technical skills. 
• No immediate results are available and may vary based on the issue and fixing method. 

Professional Fix Thunderbird Not Working with Office 365

Since the manual methods aren’t a direct fix, Thunderbird Backup Tool acts as an immediate solution. It enables users to instantly save Thunderbird data in the desired format or directly import it into Office 365 without hassle. Additionally, it has advanced filters for duplicates, selective exports, and much more. Moreover, it works directly with Thunderbird MBOX files and is easy to use across all OS, with or without technical skills. 

Note: To try its functionality and perform a few free exports, download the Demo Version of the software. 

Procedure: When Thunderbird Failed to Connect to Office 365

1. Launch the Thunderbird Backup Software and click Continue once it starts. 
2. Then, import the Thunderbird MBOX files or profile and click Next. 
3. Afterward, check the preview of the emails and select the folders to move. Tap Next. 
4. Furthermore, opt for a desired file format or an email client in which you want to secure data. 
5. Finally, apply the filters, pick a destination, and click Convert to complete. 

Conclusion 

Thunderbird isn’t the problem; it’s just that Microsoft has raised its security standards and requires a proper connection without hampering data. We have seen various manual fixes in this guide. If that doesn’t work out for you, it is best to secure your data and create a backup for it with the dedicated SysInfo Thunderbird Email Backup Tool. It is an effortless, time and cost-saving solution with 100% accurate results and no loss. 

Frequently Asked Questions

About The Author:

Simran Bhatia

Simran Bhatia is a technical content writer engaged in writing clear, concise, and SEO-optimized content. With a background in computer science and a passion for writing, I thrive to deliver complex technical content in simple layman terms.