Live Chat
Home » Import » Email Client » Import MBOX to Thunderbird – A Complete Step by Step Guide
Email Client

Import MBOX to Thunderbird – A Complete Step by Step Guide

Sherry James | Modified: 2022-10-20T12:52:12+00:00
import mbox to thunderbird

Mozilla Thunderbird is one of the most popular desktop-based email applications. It is a cross-platform client that offers wide ways of emailing options to the users. Most users look for solutions to import MBOX files to Thunderbird because MBOX is a file extension used by various desktop-based email clients like Eudora, Entourage, Opera Mail, Thunderbird, etc to store emails.

In some cases, users have an MBOX file and they need to import it to some application in order to access it. Thus, a user can upload their file into Thunderbird and access all emails stored in it. Now, the question is how it can be done in an efficient manner.

In this article, you will learn how to import MBOX to Thunderbird for free as well as quickly. There are two different ways to achieve this. First is the free method that requires you to install an add-on. While the second method makes use of a professional solution recommended by experts.

User Queries

Let us understand the situation of users who wish to use Mozilla Thunderbird to open MBOX file mail on Windows OS.

“Hi, I was using Apple Mail in my previous office but now I have changed my job. I have an MBOX of my Apple Mail which I want to transfer to my new email client. I am using Thunderbird in my new office so I urgently want to move my files to Mozilla Thunderbird. Could someone help me in the same?”

“Hello! I have been using Thunderbird for a long time but recently my system got corrupted so I had to uninstall my old Thunderbird my old MBOX File is still existing and I want to import it into my new profile. I am unable to do it so looking for a method. If anyone knows, please suggest.”

Manual Method to Import MBOX File to Thunderbird

Remember: This manual method has a few drawbacks to it which is why experts recommend using a high-end professional tool explained afterward. It will make sure that data is imported safely & no signs of data loss are seen.

Phase 1 – Install the Free Add-on in Mozilla Thunderbird

Mozilla Thunderbird provides a way to add additional capabilities with the help of extensions/add-ons. One such add-on is ImportExportTools NG which is completely free. It helps in importing MBOX files into Thunderbird 68 and above versions.

Follow the steps mentioned below to install the free add-on:

  • Launch Thunderbird by navigating to Programs and then Mozilla Thunderbird.

launch mozilla thunderbird

  • Click on the Display the Thunderbird Menu icon (3-lines) in Thunderbird.

click on the 3-lines icon

  • Now, click on the Add-ons and Themes option from the dropdown list.

select addons and themes

  • Type “Importexporttools” in the search bar, then press the Enter key.

search for importexporttools

  • In the new window that appears, click on the Add to Thunderbird button corresponding to the ImportExportTools NG button.

add to thunderbird

  • Click the Add button to provide permissions to the add-on.

click the add button

  • Finally, restart Mozilla Thunderbird once the add-on is installed successfully.

Now, move on to the next phase to complete the manual process

Phase 2 – Import MBOX to Thunderbird

Follow the steps mentioned below:

  • In Thunderbird, right-click on the mailbox in which you want to import the MBOX file.
  • Afterward, a list of options will appear, select ImportExportTools NG >> Import mbox file option to start the procedure.

Import MBOX File to Thunderbird

  • In the Files MBOX import window that appears, select import directly one or more Mbox files, then click the OK button.

import one or more mbox file

  • Then, locate the MBOX file from the location where it is stored on the hard drive.
  • Click on the Open button to import MBOX file to Thunderbird application.

select the mbox file

  • This imports the emails successfully in Thunderbird.

Problems with the Manual Method

  • A user cannot move MBOX File in batches.
  • Thunderbird does not have an in-built tool to import MBOX. One needs to install the add-on first.
  • It often leads to lost attachments and broken email properties.
  • Manual methods are lengthy and time-consuming to perform.

Also Read: How to Import MBOX Files into Microsoft Outlook?

Expert Recommended Method to Import MBOX File in Thunderbird

In order to overcome the limitations of the manual method, a user is advised to switch to a trusted third-party tool. The Thunderbird Import Tool is a widely used application for the same.

It is an effective and professional solution to import MBOX files in bulk. It allows users to move MBOX files along with their associated email attachments in Thunderbird.

One can also transfer selective emails from the MBOX file using date-range filters. In addition, it is compatible with all the latest Windows OS versions like Windows 11 (64 bit), Windows 10, 8.1, 8, and 7 (32 & 64 bit).

Steps to Import MBOX File to Thunderbird with the Tool

  • Launch the software on your Windows OS machine. The user interface of the software is as follows:

start thunderbird import tool

  • Now, click on Add Folder button and select the folder that contains the MBOX files.

select add folder

  • Once the file is added, the software will display all the MBOX files or folder that you have imported within the software interface, click on Next.

mbox files are added

  • Select the Identity/Account folder in which you want to import the MBOX file.

select thunderbird identity

  • Finally, click on the Import button to upload MBOX files into Thunderbird account.

click import button

  • Click the OK button once the files are uploaded successfully.

files imported successfully

  • Users can view all the imported emails within the Thunderbird email client on the system.

Step 5

After this, you can open MBOX file in Thunderbird and all your emails will get imported to the chosen email client successfully.


Thunderbird is an extensively used email client and MBOX is the standard email file format for many email clients. So, there comes a time when people need to import MBOX file to Thunderbird. The above article clearly states how to open these files in Thunderbird without any hassle.

There are both manuals as well as professional solutions available that one can try. However, due to its limitations and insecure results Manual method is discarded by professionals. So an autonomous application is explained with methods that are easy to follow and self-explanatory.