Free Method to Import MBOX into Thunderbird – Complete Tutorial

import mbox in thunderbird

December 22nd, 2021 ~ Email Tips ~ 3 Minutes Reading

Do you have an MBOX file and want to import it in Mozilla Thunderbird?

This blog covers the free method to import an MBOX file into Thunderbird in detail.

Email client like Mozilla Thunderbird, SpiceBird, Apple Mail, Eudora, SeaMonkey, Opera Mail, and Google Takeout supports MBOX format. If you are planning to move MBOX files into Thunderbird, so you came to the right place. But, if you want to shift another file format such as MBOX to PST, MBOX to PDF for different types of situations and users’ needs.

Knowledge of Mozilla Thunderbird

Thunderbird is a desktop-based email client application developed by Mozilla Foundation that is available for multiple platforms. By using POP or IMAP protocols you can configure multiple email account in Thunderbird. Besides email management, this email application contains a calendar, contacts, chats, feeds, and newsgroup capabilities. Its mailbox data is saved in an MBOX file.

Thunderbird is available for both Windows and Mac OS, and several user prefer Thunderbird for opening MBOX files. There are formats similar to MBOX. For instance, Opera Mail saves data in MBS file format, whereas Eudora Mail saves data in MBX files. You can also open them in Thunderbird after changing their extensions.

Reason – Why Import MBOX in Thunderbird?

The reasons for adding MBOX files to Thunderbird depend on the user’s situation. Thunderbird is one of the most popular email clients and people who use it often export and import Thunderbird mailboxes. Since it supports the MBOX mailbox, importing MBOX files in Thunderbird is a common phenomenon.

Best Way to Move MBOX file In Thunderbird

Installing an add-on in Mozilla Thunderbird is required for the import process.

Note: Check that add-ons is installed or not. If Add-ons are not installed, so first add Add-ons (Step 1). And then move forward to step 2.

Step 1: Install Free Add-on

ImportExportTools NG add-on works on Thunderbird 60.* – 78.* versions.

  • Firstly, run and open the Thunderbird in your System.

login thunderbird account

  • Secondly, click on three lines on your upper right side.

click 3 lines

  • Thirdly, select the Add-ons option from the drop-down menu.

add Add-ons option

  • Then, Type Import/ExportTools NG (NextGen) on the search bar of the upper right corner.

search importexport option to import mbox to thunderbird

  • After that, ImportExportTools NG appears on the screen, click Add to Thunderbird button.

add to thunderbird

  • Finally, Add the Add-on in Thunderbird successfully.

Add-ons successfully

Step 2: Import MBOX to Thunderbird

The MBOX files can be directly imported in Thunderbird POP account and Local Folders. You cannot import it in an IMAP account directly. For IMAP, simply import MBOX file in Local Folders and then select the emails and Copy to/ Move to the messages to the IMAP folders.

  • Open the Mozilla Thunderbird application.
  • Right, click on your ID upper left side corner.
  • Mouse over ImportExportTools NG >> Import MBOX file.

click import mbox to thunderbird

  • Select the “Import directly one or more mbox file” option and click the OK, tab.

import option to thunderbird

  • Select single and all emails as per your need and click Open.

select mbox file to thunderbird

  • After that, all the emails are import in Thunderbird successfully.

Limitations of Manual method

If you try manually to import the MBOX file in the Thunderbird application, you may face some issues:

  1. Broken Images
  2. Lost attachments
  3. Lost emails
  4. Time-consuming


Here, we have explained one of the easiest ways of importing MBOX files in Thunderbird. There are a lot of users on the Internet who always gets in trouble and face errors while importing these files. Hopefully, with this simple solution, you can import the files for free.