Home » Blog » Thunderbird » Remove Duplicate Emails from Thunderbird Profile Efficiently

Remove Duplicate Emails from Thunderbird Profile Efficiently

Jamie Kaler   Contribution
Rollins Duke
Rollins Duke  Approved By
Published On June 10th, 2024 • 5 min read

Accumulation of duplicate emails in the email client is annoying. More than that it takes up the storage space of the email client and jeopardises the efficiency of Thunderbird. You will find different methods to delete duplicate messages from the Thunderbird profile. But we need a solution that gives instant results that can be used by users with or without technical expertise. Here, we will discuss the best method to remove duplicate emails from Thunderbird.

Removing emails from any email client can be easy but when it comes to deleting more files than from the single pages. Therefore we are here with the solutions to remove unwanted emails in batches. Go through the write-up to know more about the solution.

Table to Content

Reasons Why Thunderbird is Creating Duplicates

We have seen several cases where the user upgrades and copies the emails from one folder to another. Thus, creates duplicates in the folders. This is one of the major reasons, why users might caught up with other causes with which the Thunderbird creates duplicates.

  • Senders Side Issue: If the sender mistakenly sends similar emails multiple times then it is also one of the reasons. However, this could be the least to occur among the other two causes. 
  • Server Problem: Error in the server is the most common cause of making copies of email messages.
  • Mistakes from User’s Side: As mentioned above, when we transfer emails from one folder to another the emails can get repeated or copied.

Remove Duplicate Emails from Thunderbird in Batches 

Like any other email client, Thunderbird also offers a basic procedure to delete identical emails from the account.

  • Start the Thunderbird in your system.
  • Navigate to the Tool in the menu and choose Add-ons.
  • From the Add-on Tab manager select the Plug-in.
  • In the search box enter “Remove Duplicates” and hit the search button.
  • Now find the “remove Duplicate Messages”.
  • Click on the Install button to install the Add-on into the Thunderbird.
  • After completing the installation, press Restart Now to restart the Thunderbird.

Note: Check whether the Add-on is set up or not by navigating the add-on, repeating the above steps and enabling my add-on.

  • Now go to the folders and right click on the Folder and select “Delete Duplicates”.
  • A confirmation message will appear on the screen stating, “No Duplicate messages found”.

Loopholes of Using Manual Method The standard approach to take off the duplicates in Thunderbird takes some time to complete the task. In addition to that, there is no option if we need to delete identical emails from a particular folder.

Expert Method to Remove Duplicate Emails from Thunderbird

To overcome the limitations the use of MBOX Duplicate Remover would be a great help. It has all the features from selecting emails from different folders to scanning emails within & across the folders. Use the software to bulk delete duplicate emails without repeating any points. Removing duplicate emails could be one of the best solutions to speed up Thunderbird accounts.

Install the above-given software based on the system. The trial version will guide you on how to clean up duplicate emails with the first 20 email removal process for free.

Step-by-step Instructions to Delete Thunderbird Duplicate Emails 

  • Launch the software on the system and follow the instructions.
    launch the software
  • Add the Thunderbird Mailbox files to the panel using the Upload buttons. Hit the Next button.
    add thunderbird mailboxes
  • If the folder is selected, choose the desired folder using the Check box. Press the Next button.
    choose the desired folders
  • Now, from the options select any as per the requirements.
    set up selective duplication setting if required
  • Browse a location to store the new file else the tool creates a new folder in the default location.
    browse a location to store the output
  • Press the Export button to start the procedure to delete Thunderbird duplicate emails.
    remove duplicate emails from thunderbird for free

In a few clicks, a new MBOX file will be generated and stored in a location as selected before.

Move the File to the Thunderbird Account 

  • Start the Thunderbird Account and Go to Add-ons
  • Then, in the search tab, enter ImportExportTools NG. Click on the Add to Thunderbird.
    get importexport ng add-on
  • Soon the installation will start and after completion press Restart Now to start Thunderbird again.
  • From the left panel, select Local Folder.
  • Go to Tools and select ImportExport Tool NG, Import MBOX File.
    choose option to import mbox files
  • Select the MBOX files created before.
  • Again, Restart Thunderbird to preview the imported mailboxes.


The write-up has complete instructions to remove duplicate emails from the Thunderbird profile. Go with the automated or manual approach to get the duplicates out of the Thunderbird email clients. We have discussed the major reasons why the duplicates are being created and the solutions respective to that. If there is a need to bulk delete Thunderbird messages then use the automated approach.

Frequently Asked Questions

Q1) Does the Remove add-on work on the Thunderbird account?

A1) Yes. Use the Remover Add-on to eliminate identical emails in the Thunderbird.

Q2) Is there any simple approach to deleting duplicate messages from Thunderbird without Add-on?

A2) Yes. Use the mentioned software to clean up the duplicate emails in the Thunderbird profile effortlessly.