Import MBOX is Disabled in Thunderbird Error – [Solution 2026]

Are you continuously facing issues while importing MBOX files in Thunderbird email account but the option is greyed out? Not to worry at all because you are not alone in this, in the blog we will explain the reasons behind the error and how to fix Import MBOX is disabled in Thunderbird issue with ease. Also, we will go through different methods, common causes as well as pro tips to access imported files successfully.

MBOX is a common file format which many email applications make use of to save their email messages including Thunderbird. However, Thunderbird does not have MBOX file import option by default in its older version. But in Thunderbird 115, there is an inbuilt option which also fails sometimes when try to import MBOX file. So, in the write-up, we will discuss all the necessary ways to fix Import MBOX is disabled in Thunderbird error.

Quick Note. To fix Import MBOX file is disabled in Thunderbird error, either install/update ImportExportTools NG add-on, verify the compatibility of Thunderbird version and make sure the file permissions are applied correctly for MBOX file.

Why Import MBOX is disabled in Thunderbird Error Occur?

As we know that Thunderbird not able to import MBOX files directly in its email account. For that, it is essential to install ImportExportTool NG add-on. Here are main reasons why Import option is greyed in Thunderbird –

• ImportExportTools NG add-on is outdated or not working.
• Thunderbird version is not compatible with the installed add-on.
• File permissions of MBOX file restrict Thunderbird from retrieving the file.
• Thunderbird account is corrupted.

How to Fix – Import MBOX File Disabled in Thunderbird!

Follow the multiple solutions discussed in the segment and fix import MBOX file disabled in Thunderbird error –

Solution 1. Install ImportExportTools NG add-on

To import MBOX file, install ImportExportTools NG add-on. And to perform the same, go through the below steps –

1. Run Thunderbird.
2. Go to Tools, select Add-ons and choose Themes.
3. Search for ImportExportTools NG using Search tab.
4. Install the add-on.
5. Restart Mozilla Thunderbird.

After the process completes, you will be able to see Import MBOX File option appearing under the Tools >> ImportExportTools NG menu.

Solution 2. Update the Version

With older Thunderbird version, you will encounter compatibility issues with add-ons. Here are the steps –

1. Run Thunderbird email client.
2. Navigate to Help menu and select About Thunderbird.
3. If the update is available, download and install the same immediately.

Note. Ensure to update Thunderbird and ImportExportTools NG regularly for better experience.

Solution 3. Verify MBOX Files Permission

Even if everything is correctly installed, Thunderbird won’t able to read your file if its permissions are not appropriate. Follow the steps to verify the permission –

1. Right-click on the required MBOX file.
2. Go to Properties if working on Windows and Get Info if using Mac.
3. Ensure you have Read & Write access.

Make sure that MBOX file is not in use in another program while importing.

Solution 4. Generate new Profile in Thunderbird

In case you are still facing the same error, then there might be a corruption issue. To fix the problem follow the steps discussed below –

1. Close Thunderbird email client.
2. Press Win + R, write Thunderbird.exe –p, and tap Enter.
3. Tap Create Profile and follow the Wizard.
4. Install the ImportExportTools NG add-on in a new profile.

This will generally fix constant import issues.

How to Fix Import is disabled in Thunderbird Error Issue?

By utilizing MacMister MBOX Converter for Mac & Windows, users can import MBOX files into Thunderbird email client with 100% accuracy. It is an easy and safe way to resolve disabled issue in Thunderbird. The solution will quickly transfer MBOX data into Thunderbird directly such without altering the email hierarchy and structure. However, you may also use the demo version of the tool to evaluate and analyze the complete processing of the application for free.

Steps to Fix Import is disabled in Thunderbird error on Mac

Step 1. Install and run the software on Mac OS.

Step 2. Tap Add File(s) option to upload the required .mbox files on the software and make use of Add Folder option if you have multiple MBOX files that you want to save them simultaneously on your Mac at once. After the files are listed, tap Next to proceed.

Step 3. In the next window, the tool will show the entire list of MBOX files with checkboxes that are selected by default. However, one may deselect them and select them again as per their needs to save specific MBOX files into Mozilla Thunderbird on Mac. Click the Next button again to continue.

Step 4. Now, using the Select Saving Options drop-down menu, pick Thunderbird saving type.

Step 5. Set Thunderbird options as per the requirements and tap Export.

Step 6. View the Live Conversion Report screen to verify the current import status of MBOX files.

Within seconds, the procedure will finish with a message “Conversion Completed Successfully”. Click OK to close the same. Then go to Thunderbird email client to cross-check imported files. However, after viewing the imported file in Thunderbird, you will see that the data is appearing with correct content and metadata properties.

Epilogue

In the write-up we have tried to provide the best possible ways to fix “Import MBOX file is disabled in Thunderbird” error. There are different ways mentioned to resolve the issue. Users can apply the manual techniques if needed or directly make use of a professional way to import MBOX files directly into Thunderbird email client. In case of any assistance, contact MacMister Support.