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How to Import PST to Thunderbird Without Outlook? (2026 Updated Guide)

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Published By Jamie Kaler 
Rollins Duke
Approved By Rollins Duke
Published On September 8th, 2026
Reading Time 9 Min Read

How to import PST to Thunderbird without Outlook has become a major issue among users. The reason for this is the increasing demand for Thunderbird email applications. It has now become a very well-known platform for data storage and for the instant email function for its users.
The main reason for using the Thunderbird email client is that it is a free desktop-based email client application. But Thunderbird supports MBOX format to store mailbox data, not PST format.

“Hello, I am using Microsoft Outlook 2010 on my old computer. On that computer, I was facing many issues. So, I bought a new Windows 10 computer. On this computer, I have installed the Thunderbird email client. I have already exported PST from the old account. But the problem is how to import PST to Thunderbird without Outlook. Does anyone know how to import the entire data? Please help me to resolve this issue.”

If you are one of those who want to import PST to Thunderbird, then continue with the next section and read the complete article.

Why Users Want to Open PST in Thunderbird Account?

Thunderbird comes with amazing features and filters for free, which makes it the first choice of users over PST format. Because Outlook creates PST format, which comes with a high subscription amount, not all users can afford it. Some of the amazing things about the Thunderbird email client are given below which compel users to import PST to Thunderbird without Outlook installation:

  • Thunderbird is a free and open-source email client, while Outlook usually costs money.
  • Thunderbird has a simple and easy-to-use interface for all users, so users can easily use it without having any errors.
  • Some people think Thunderbird is safer and respects privacy more.
  • Outlook creates only PST, MSG, and OST files, which are only compatible with Outlook, while Thunderbird creates MBOX, which is compatible with multiple email clients.

How to Import PST to Thunderbird without Outlook?

  1. Run the tool on PC.
  2. Select PST files with dual options.
  3. Choose the required folders/subfolders.
  4. Select Thunderbird as the saving option.
  5. Apply the filters and select the path.
  6. Get the resultant exported PST files.

To know more about these steps, you can go directly to the automatic solution paragraph and read all the information about it.

Can Thunderbird Open PST Files?

No, Thunderbird cannot import PST files directly. To do that, you have to convert the PST format into any Thunderbird-supported format like .mbox. Moreover, you can also use Gmail as a bridge to import PST data into Thunderbird.

Preparation: Here we have explained mixed methods, like with or without Outlook installation. So, if you have an orphan PST, first upload it to your Outlook account by following these steps:

  1. Open an Outlook account.
  2. Go to the File tab section.
  3. Select Open & Export and then Import/Export.

    Import/Export

  4. Press on “Import from Another Program and File”.

    Import from Another Program

  5. After that, select “Outlook Data File (.pst)”.

    Outlook Data File

  6. Browse the orphan data file.

    orphan data file

  7. Select the folder in which you want to keep the file.

    select the folder

  8. Lastly, click on the Finish button.

Also, to complete the manual method later, you will need to connect your Gmail account to Thunderbird. Modern email clients now use secure Google sign-in prompts, meaning you only need your standard Gmail address and password. You no longer need to manually enable IMAP or create App Passwords.

Method 1: How to Import PST to Thunderbird via Outlook?

Thunderbird has a built-in feature to connect with an installed Outlook account by following these steps:

  1. Firstly, open the Thunderbird email client.
  2. Click on the Tools >> then go to the Import option.
  3. Now select the Import from Outlook option from the list.
  4. Enter the required details if required.

This is how you have successfully connected both accounts. Now you can import PST data into Thunderbird

Method 2: Import PST to Thunderbird Using Gmail

You can also use Gmail as a bridge to import PST files to Thunderbird. Although this method is quite lengthy and technical, it can help. Follow the given steps carefully:

Step 1: Connect Gmail Account

Important Note: Follow these steps after you have installed Outlook and have uploaded a PST file in it.

  1. Open an Outlook account.
  2. Navigate to the File option and click on the Add Account button.

    Add Account

  3. Enter your Gmail email address and login securely using Google authentication.

    Enter the login details

  4. Lastly, hit the Finish button once the setup is completed.
  5. Now drag and drop the emails from Outlook mailboxes to your connected Gmail account to continue importing PST files to Thunderbird.

Or, if you have an orphan PST file and do not want to install the Outlook client, follow these steps:

What is the GWMMO Tool: It is a tool that allows users to upload an Outlook profile or PST file to a Gmail account for free. Remember, this tool will not work with damaged files.

  1. Download and install the GWMMO tool.
  2. Log in with your Gmail account using the secure browser pop-up.

    GWMMO tool to Import pst to thunderbird

  3. Grant all required permissions.

    required permissions

  4. Upload your PST data file.

    PST data file

  5. Select between Migrate All Data or New Data options.

    Migrate All Data

  6. Click Next and check the needed boxes.

    needed boxes

  7. Click on the Migrate button and the live process will start.

    live process

  8. After complete migration, a pop-up will appear; hit the OK icon.

    complete migration

  9. Lastly, you can check what the resultant data looks like.

    resultant data

After importing the PST file to your Gmail account, move to the next steps to open PST in Thunderbird.

Step 2: Export Outlook PST from Gmail as MBOX

You can migrate Gmail data to Thunderbird in two ways: using Google Takeout or connecting the accounts directly. Both methods are explained below:

  1. Open your Google Takeout account.
  2. Click on the Deselect All option.

    Import MBOX Files

  3. Select the required data (Mail) and hit the Next button.

    Import MBOX Files

  4. Select the file size, type, frequency, & destination.

    Import MBOX Files

  5. After that, hit the Create Export button to start the process.

    Import MBOX Files

  6. This will download a Zip file. Extract it to get .mbox file.

Step 3: Import PST into Thunderbird as MBOX

Important Note: First open Thunderbird and install ImportExportTools NG extension.

  1. Open your Thunderbird account.
  2. Open the menu, click on Tools >> Select ImportExportTools NG >> Then click on Import MBOX files.

    Import MBOX Files

  3. After that, choose the Import One or More MBOX files option.

    Import One or More MBOX Files

  4. Browse to the MBOX file that you just received using Google Takeout and import it into Thunderbird.

    Browse the exported MBOX file

This is how you can import PST files into Thunderbird. But before you start the process, read about its limitations.

Important Note: If this method seems too lengthy, you can use the direct connection method explained below.

Step 2.1: Connect Gmail to Thunderbird Directly

  1. Open your Thunderbird account.
  2. Click on the Tools option and then Account Settings.

    account settings

  3. Hit the Account Actions button and then select Add Mail Account.

    account actions

  4. Type your name and Gmail email address. After this, Thunderbird will automatically launch the Google sign-in window for authentication.

    login credentials

  5. Login to your account using Google authentication.

    Import pst to thunderbird

  6. Locate the uploaded PST file and import it into Thunderbird mailbox.

Drawbacks of Manual Methods

  • Requires Microsoft Outlook: Many processes do not work unless you have an active installation of Outlook.
  • Time Consuming: Transferring large amounts of email can take a long time, often taking hours.
  • Storage Limits: Transferring PST files will quickly eat up the 15GB limit of free space with Gmail.
  • Highly Technical: A combination of technologies, setups, and third-party tools is required.
  • Data Risks: There is a possibility that the folder structure from the source PST may get lost in this method.
  • No Corruption Support: If there is a little damage in the source PST file, the entire process fails.

Professional Solution to Import PST to Thunderbird Without Outlook

To avoid tedious manual conversions and prevent data loss, specialists suggest the usage of the RecoveryTools PST File Converter. This software is specifically designed to allow users to easy import of single or multiple PST mailboxes into Thunderbird without requiring Microsoft Outlook in the system.

Complete Steps to Open PST File in Thunderbird Account:

  1. Just download and open the PST to Thunderbird converter and click on Next.
    open the tool
  2. Use the dual selection mode to choose PST files or folders directly from your system.
    select the files
  3. Select the required email folders from the list and hit the Next button.
    select the folders
  4. Select Thunderbird from the list of saving options to easily open PST files in Thunderbird without Outlook.
    import pst to thunderbird
  5. Filter specific data using advanced filters to import desired PST emails to Thunderbird.
    apply filters
  6. Software will automatically detect the Thunderbird path on your system. Also, you can manually browse and choose the desired path.
    choose destination path
  7. Click on the Convert button to import PST to Thunderbird.
    open pst file in thunderbird

Why Choose Professional Tools Over Manual Methods?

  • Simple and easy-to-use interface designed for both technical and non-technical users.
  • Automatically loads data from default storage locations if Outlook is configured on the machine.
  • Supports adding single or multiple PST files and folders to Thunderbird.
  • Maintains folder hierarchy and all email components (Bcc, Cc, To, From, Date, Subject, Formatting, Images, Signatures).
  • Allows selective email migration across default folders (Inbox, Sent, Draft, Trash, etc.).
  • Enables bulk PST migration to Thunderbird without file size limitations.

Frequently Asked Questions

  • Can I open a PST file without Outlook?

    Yes, you can open your PST file without installing Outlook by using the RecoveryTools PST Viewer tool.

  • Why can’t I import PST files?

    It mostly happens, when you have a corrupt PST file to import. So first you have to repair your file using the RecoveryTools PST Repair tool. for complete information, follow the given solution page.

  • How do I extract Outlook PST files?
    1. Open your Outlook email client.
    2. Select the File >> Open & Export >> Import/Export.
    3. Choose the Export to a File option.
    4. After that, select the Outlook Data File (.pst) option.
    5. Check the folders, which you want to export.
    6. Browse the location to save the resultant data.
    7. Apply the filters and click on the Finish icon.
  • Where is my Outlook PST file located?

    Here you can follow this location to locate your PST files in different Windows:

    • Windows 10 drive:\Users\<username>\Documents\Outlook Files
    • Windows 11 drive:\Users\<username>\Documents\Outlook Files
    • Older versions of Windows drive:\Documents and Settings\\Local Settings\Application Data\Microsoft\Outlook
  • What is the size limit for Outlook PST files?

    50 GB is the size limit for Outlook PST files.

Conclusion

In this article, we have explained the complete process to import PST to Thunderbird without Outlook. The automated solutions are reliable, user-friendly, and require minimal technical expertise. You can also download a free demo version of the PST to Thunderbird Converter to test importing the first 25 emails from each folder.

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