How to Migrate Thunderbird to an Office 365 Account?

Office 365 (Microsoft 365) – a cloud-based subscription service – provides various productivity tools, including Outlook for email communication, Microsoft Teams for collaboration, and others. It offers flexibility of accessing data from anywhere, at any time, and using any device. Due to these and various other benefits, businesses and organizations prefer this cloud-based service over desktop-based email clients, like Mozilla Thunderbird.

However, migrating from Thunderbird to Office 365 is not a simple task as both platforms use different data file formats. Thunderbird stores the mailbox items in MBOX file format, whereas Office 365 supports PST file format. But there are various specialized MBOX to PST converter tools available that can help in migrating data from Thunderbird data (MBOX) to Office 365.

In this post, you will know the detailed process of migrating data from Thunderbird MBOX file to Office 365 using a reliable MBOX to PST converter tool. You’ll also learn a workaround to migrate mail items from Thunderbird to Office 365.   

Why Migrate from Thunderbird to Office 365?

Switching from Mozilla Thunderbird to Office 365 has several advantages for businesses and users, such as:

• Users can access emails, contacts, calendars, etc., from anywhere, anytime, and using any device. All it requires is an active internet connection.
• Users can use collaborative applications, such as Microsoft Teams, SharePoint, OneDrive, Word, Excel, PowerPoint, and more.
• It offers enterprise-grade security features, like Multi-Factor Authentication (MFA), Advanced Threat Protection, etc., to safeguard user data and privacy.

Key Differences between Mozilla Thunderbird and Office 365 (Microsoft 365)

Here are some key differences between Mozilla Thunderbird and Office 365.

Simplest Way to Migrate Thunderbird Data to Office 365

An easy way to migrate Thunderbird data to an Office 365 account is by using Stellar Converter for MBOX Technician – an advanced MBOX to PST converter tool. With this tool, you can effortlessly migrate Thunderbird MBOX file data, including emails, contacts, calendars, etc., to an Office 365 account with 100% accuracy and complete data integrity. It uses Microsoft’s Modern Authentication technique to securely connect and export the MBOX file data to mailboxes on Office 365 (Microsoft 365).

This tool also lets you convert and save the MBOX file data in PST, PDF, RTF, EML, etc. Apart from Thunderbird, it supports MBOX files of almost all MBOX-based email clients, including Apple Mail, Eudora, Entourage, Netscape, SeaMonkey, Spicebird, and Google Takeout.

Now, let’s see how to use this tool to migrate Thunderbird MBOX data to Office 365:

Before you Proceed: Export Thunderbird mailbox data to an MBOX file (if not already).Configure your Office 365 account in the Outlook desktop application installed on your system.

• Download and install Stellar Converter for MBOX Technician from its official website.
• When you launch the tool, you will see the Select MBOX window. Use the dropdown menu against the Select Mail Client option to select the email client (Thunderbird).

• Once you select the Thunderbird email client, the tool will automatically select the default path of the Thunderbird MBOX file.

Note: If you want to select MBOX file stored at a different location, click on the Select Identity button.

• After selecting the MBOX file, click on Convert.
• The tool will scan the MBOX file and display all the mailbox items.

• You can preview the mailbox items.

• Select the items you want to export to Office 365 and click on the Save Converted File button under the Home tab.

• Choose the Export to Microsoft 365 option in the Save As window. Click Next.

• The Microsoft 365 Login window will appear. Use the dropdown list to select the Microsoft 365 profile in which you want to migrate Thunderbird data. After selecting the profile, click on Migrate.

Note: The tool will automatically detect the Office 365 profile configured with the Outlook application.

• Once the Thunderbird MBOX data is successfully migrated to Office 365 account, you will see the Migration Successful dialog box. Click OK to complete the process.

You can also use this tool to convert Thunderbird MBOX file to PST file and then import the PST file into Office 365.

Manual Method to Migrate Thunderbird Data to Office 365

There is a workaround to migrate Thunderbird data to Office 365. In this, you need to configure the Office 365 account in Thunderbird, and then drag and drop the mail items from Thunderbird into Office 365. Follow the steps given below:

• Launch Mozilla Thunderbird on your Windows PC.
• Click on the gear icon at the bottom-left corner to open Settings.
• Click on Account Settings.
• Then, click on Account Actions in the left pane and select the Add Mail Account option.

• On the Account Setup screen, enter your Microsoft 365 credentials and click on Configure Manually.

• Next, add the following details:
  • Incoming: IMAP|outlook.office365.com|993|SSL/TLS|OAuth2
  • Outgoing: SMTP|smtp.office365.com|587|STARTTLS|OAuth2
• Click Re-test to test the settings. Once it is successful, click on Done.

Wait for the completion of synchronization. Then, drag and drop the required emails from your Thunderbird into Office 365.

Limitations of the Above Workaround

The above workaround can work but it has some limitations, such as:

• It is suitable for migrating only emails.
• It is a lengthy and time-consuming process.
• Thunderbird may fail to establish connection with Office 365 account due to incorrect configuration settings.

Wrapping it Up

As there is no direct way to migrate Thunderbird data to Office 365, you can configure Office 365 account in Thunderbird – a workaround to migrate emails or use a specialized MBOX to PST converter tool. However, the best option is to use Stellar Converter for MBOX Technician. This tool can help you to directly migrate mailbox data from Thunderbird MBOX file to your Office 365 Account.