How to Migrate Thunderbird to Outlook?

What is Thunderbird?

Thunderbird is a cross-platform, open-source email client that allows users to send and receive emails, create contacts, and more. It stores emails, attachments, and other mail items in MBOX files on the local machine.

However, thunderbird prone to crashes due to bugs, virus attacks, unexpected application errors, or other reasons. Hence, many users try to find ways to migrate Thunderbird to Outlook. Let’s read further to know how you can migrate your Thunderbird mailbox data to the MS Outlook (2021, 2019, 2016 and 2013)

Why Users Migrate Thunderbird to Outlook?

Although Thunderbird is a free email client, there are several reasons why users look for ways to migrate from Thunderbird to Outlook. Some of these are:

• When connected with Office 365, Outlook can be used on any device to access emails, contacts, and other mail items. 
• Users can use various collaborative applications, like Microsoft Teams, OneDrive, Word, Excel, PowerPoint, and more with Outlook.
• Outlook offers enterprise-grade security features, like Multi-Factor Authentication (MFA), Advanced Threat Protection, etc., to safeguard user data and privacy.

What are the Methods to Migrate Thunderbird to Outlook?

Here are some ways or workarounds that can help you migrate Thunderbird to Outlook 2021, 2019, 2016, and 2013.

Method 1: Save Thunderbird Emails to EML Files and Import them into Outlook

One easy way to migrate Thunderbird to Outlook is by saving the Thunderbird emails in EML files and then importing these files into Outlook. However, this is feasible if you need to migrate only a few emails. Here’s how to do so:

Step 1: Save Emails to EML File

• Open File Explorer on your PC and create a new folder to store EML files.
• Open the Mozilla Thunderbird application.
• Hold the Shift key and click on the emails in the Thunderbird mailbox that you want to migrate to Outlook.
• After selecting emails, right click on them and go to Export Messages As > EML Message Format.
• Click on the Messages (Attachments Embedded) option.

• Choose the new folder (created above) and click on Select Folder.
• The selected emails will be saved in EML file format.

Step 2: Import EML Files into Outlook

• Launch Outlook application where you want to import Thunderbird emails.
• Create a new folder in the Outlook.
• Open the folder that contains the EML files.
• Now drag and drop the EML files to the Outlook folder that you just created.

Limitations of the Above Method

• It is a time-consuming and repetitive process as you will have to select and save emails from each folder separately.
• Saving emails from multiple folders can result in lost folder structure and hierarchy.
• EML files may not preserve metadata and other information (CC/BCC).

Read More: How to Use ImportExportTools NG in Thunderbird?

Method 2: Migrate Thunderbird to Outlook using an MBOX to PST Converter Software

You need to first convert the Thunderbird MBOX file to PST file format. For this, you need to use a specialized MBOX to PST converter tool. One such tool is Stellar Converter for MBOX.

Available as both online utility and a desktop-based application, Stellar Converter for MBOX lets you convert MBOX files to Outlook-importable PST file format.

You can easily use the online MBOX to PST converter utility on any device – be it a Windows PC, a Mac, or a Linux system. All you need is a web browser and an active internet connection. You can use it to convert an MBOX file of ≤ 100 MB size for free.

If you want to convert multiple MBOX files without any file-size restriction, you can opt for Stellar Converter for MBOX desktop application. It is an advanced Thunderbird to Outlook converter tool that can easily convert MBOX file to PST format while keeping the folder structure and hierarchy intact. Apart from PST, it can save the MBOX file data to RTF, PDF, and HTML formats. 

The tool can also convert multiple MBOX files. It offers an intuitive user interface that is simple to navigate even for a non-technical user. The advanced software is also capable of directly exporting the converted MBOX file data to an existing Outlook profile. You can also use it to directly migrate Thunderbird to a Microsoft 365 account. It can also convert files of other MBOX-based email clients, like Eudora, GNU, Spicebird, Apple Mail, and more.

Here are the steps to convert Thunderbird MBOX file to Outlook PST using this tool:

• Download and install Stellar Converter for MBOX on your Windows PC.
• Launch it.
• The Select MBOX window will appear.

• Select the email client (Thunderbird) from the Select Mail Client dropdown menu.
• The tool will automatically select the path of the default MBOX file (if Thunderbird is installed).

• After selecting the MBOX file, click on Convert.

• After the conversion, the software lists all the Thunderbird mail items in a tree-view structure. Select any mailbox item to generate its detailed preview.

• Click on the Save Converted File button under the Home tab.
• Choose the Save As PST option in the Save As window. Click Next.

• Click on Browse to choose the destination folder. Click Save.

Once you have successfully converted the MBOX file to PST, you can use the Outlook’s import/Export wizard to import the PST file into Outlook. Here are the steps:

• Launch your Outlook application (2013, 2016, 2019, or 2021) and go to File > Open & Export > Import/Export. If you’re using Outlook 2010, then navigate to File > Open > Import.

• Select the Import from another program or file option from the Import and Export wizard and click Next.

• Choose Outlook Data File (.pst) and click Next.

• Click Browse to choose the converted PST file and then click Next.

• In the next window, select the folder where you want to import the Thunderbird emails. Click Finish.

This will migrate all the Thunderbird mail items to Outlook.

Conclusion

Above, we have explained some effective ways to migrate Thunderbird to Outlook. However, the simplest and safest way is to first convert the Thunderbird MBOX file to PST and then import the PST into Outlook. To convert MBOX file to PST, you can take the help of Stellar Converter for MBOX - a professional MBOX to PST converter tool to convert MBOX files to PST format in just a few simple steps. This tool supports MBOX files of all popular email clients, including Thunderbird, Apple Mail, SeaMonkey, and Entourage.