Microsoft Outlook is a part of the Microsoft Office suite developed by Microsoft. The primary use of the MS Outlook is email management. In addition, it provides task management, contact management, note taking, journal management, etc. In most of the organizations, it works in synchronization with the Microsoft Exchange Server. However, it can also be used as a stand-alone application.

On the other hand, Thunderbird is a free; cross-platform developed my Mozilla. It acts as an email, newsgroup, and chat client. With this, you can easily manage multiple email, newsgroup, and news feed accounts, etc. In addition, it provides features like quick search, saved search folders, advanced message filtering, message grouping, etc. With so many features, one might consider to migrate from Outlook to Thunderbird. However, there could be many other reasons to transfer Outlook mailboxes to Thunderbird.

In either of the case, it is advised to use an efficient software. Stellar Converter for PST Converter is a reliable software to convert Outlook PST files into an importable format for Thunderbird. The tool helps you import PST to Thunderbird by seamless conversion of PST files to MBOX format.

Following are the steps to convert PST to MBOX, using Stellar Converter for PST.

Step 1: Select the PST File to be converted
1. Launch the software
2. The main interface opens up along with a 'Select Outlook Profile & MBOX Client dialog' box as shown below.

3. The dialog box displays a list of already configured profiles. You can either choose a profile from the list of configured profiles or any desired Outlook profile. In case you wish to choose another PST file, you need to navigate to the location of the file using the 'Find PST File' option as shown below.

4. Once you have selected the PST file to be imported, you need to select the MBOX client.
In this case, select Thunderbird.

5. Click 'OK' to start the scanning process as shown below.

(Note: In case the PST file is password-protected, you need to specify the password in the 'Enter Outlook PST Password' dialog box and click 'OK'.)


Step 2: Previewing Mailbox Items in Main Interface

1. Once the scanning process is complete, the software displays all the mailbox items in a tree-like structure. The left pane displays various mailbox folders.
2. Click on any folder in this list to display all the mails in the folder in the front pane.
3. Click any particular mail item to have a preview in the main interface as shown below.
Step 3: Converting and Saving Mailbox Items

1. Click the 'Convert to MBOX' button on the toolbar, to start the conversion process.
2. Stellar Outlook PST to MBOX Converter dialog box appears up.
3. Choose a preferred destination path to save the converted mails and click 'OK' as shown below.

Note: Once the conversion process is complete, you can check the converted MBOX file by navigating to the specified location. Finally, you need to import the MBOX file to the Thunderbird client to access emails. However, there are different ways of importing an MBOX file in Thunderbird running on different Windows platform.

Windows XP

For Windows XP, you need to copy the converted file to the following directory path:

C:\Documents and Settings\Administrator\Application Data\Thunderbird\Profiles

Windows Vista

For Windows Vista, copy the converted file to the following directory path:

C:\Users\Administrator\AppData\Roaming\Thunderbird\Profiles\

Windows 7 / Windows 8 / Windows 10

You need to copy the converted file to the following directory path for Windows 7/8/10:

C:\Users\Administrator\AppData\Roaming\Thunderbird\ Profiles

Once done, launch the Thunderbird. You can see the converted mails in the left pane under 'Local Folders'.