How to Remove Duplicate Emails in Thunderbird?

Mark Regan ~ Modified: 15-03-2023 ~ Remove Duplicates ~ 6 Minutes Reading

Numerous People are struggling with the thunderbird duplicate emails problem. Therefore, with that concern, we have drafted this technical write to provide the well-needed guidance and solutions on how to remove duplicate emails in Thunderbird. Read this article thoroughly to get the expert suggested method to tackle the issue.

Thunderbird is a well known open-source email client. Moreover, it is available for free of cost for the users. Other than managing your emails, you can also integrate other accounts in Thunderbird as well. However, being a mail client, Thunderbird also faces the email duplicacy issue. The duplicate emails, when few in number, aren’t really a concern. However, when they keep accumulating, they pose certain hindrances in the usual performance of the email client. Moreover, they also take up a significant amount of storage space.

Now, there are numerous techniques you can use to tackle the problem. In this article, we have shared a manual solution as well as a professional solution recommended by various experts. Furthermore, there are several reasons why you may be facing the Thunderbird duplicate emails problem; let’s check out what they are.

Possible Reasons you are Facing Thunderbird Duplicate Emails Problem

As stated above, there are more than one reason that may cause duplicate messages in Thunderbird; listed below.

Server Issues
The server is important in all email clients, however, on seldom occasions, there can be problems. As a result, it can download the same email repeatedly causing users seeking to remove duplicate emails in Thunderbird.

Accidental User Activity
Users have multiple folders and subfolders in their Thunderbird. With that, copying emails from one folder to another can cause duplication of your Thunderbird emails.

Mistake from Sender’s End
Due to many factors, sometimes sender’s send the same mail repeatedly to the receiver which causes duplicate emails in receiver’s Thunderbird.

These are some commonly faced reasons for duplicate emails in Thunderbird. Now coming to the question of how to remove duplicate emails in Thunderbird; we are sharing two methods in this article. Where one follows the manual approach, the other one uses an automated tool to accomplish the task.

Here, we are going to share the smart way to remove duplicate messages in Thunderbird. The primary reasons would be the limitations of the manual method that make it an unworthwhile experience for users. Therefore, to avoid wasting any of your precious time we are sharing the secure way first.

Read Similar: Easily Delete Duplicate Emails in Google Takeout Mailboxes

Expert way to Remove Duplicate Emails in Thunderbird

If you want a reliable and secure solution for the Thunderbird duplicate emails issue then this BitRecover MBOX Duplicate Remover is the best choice. This software is recommended by various technical experts because of its exceptional features and the unequaled experience that it provides. Not only does this tool maintains data integrity while deleting duplicate emails but it also supports bulk deletion to remove duplicate emails in Thunderbird.

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Impressive Features of the De-duplicator

  • Provides two options for the users to get rid of duplicate emails: Search duplicates within the Folder and Search Duplicates across the Folder.
  • The Advanced Filters let you filter out emails according to Date Range, From, To, Subject and Root Folder.
  • This utility also allows you to deduplicate selective folders.
  • Provides you with the option of setting your preferred location to save the resultant files on your system.
  • Preserves and maintains data & file structure throughout the process.
  • Generates a completely new processed mailbox instead of manipulating any data in the original files.
  • This software is compatible with Windows OS 11, 10, and other previous versions.

Furthermore, let us jump ahead to the instructions to use this tool.

Steps to Delete Duplicate Emails in Thunderbird using the Tool

  1. Download and launch the software on your computer or laptop.

    Start the software to remove duplicate emails in thunderbird

  2. After doing that, click on either Select Files or Select Folders to add your files for deduplication.

    Start the software to remove duplicate emails in thunderbird

  3. Now, choose if you want to Search Duplicates Within the Folders or Search Duplicates across the Folders.

    Start the software to remove duplicate emails in thunderbird

  4. Use the Advanced Filters in the Filter Options Tab. Choose the Selective Export Settings as per your requirements.

    Start the software to remove duplicate emails in thunderbird

  5. Then, Browse and select your preferred location path to save the resultant files on your device and click the Extract button to initiate the process.

    Start the software to remove duplicate emails in thunderbird

And that is all for the steps, as you can see in only a few simple steps you can easily use the tool to remove duplicate emails in Thunderbird. Further in the next segment, we have described the manual procedure to accomplish the task as well.

Manual Approach to Remove Duplicate Emails in Thunderbird

This manual method involves the Thunderbird add-on named “Remove Duplicate Messages”. You need to install this add-on in your Thunderbird account first and then proceed to delete duplicate emails. So, let’s see the steps to conduct it.

Steps to Execute the Manual Method

  1. Launch Thunderbird on your device
  2. Go to Tools >> Add ons
  3. Search for ‘Remove Duplicates’ and install the first add on in the search list.
  4. After installing the add-on, restart your Thunderbird account
  5. Upon restarting, right-click on the mail folder that you want to deduplicate and select the ‘Remove Duplicate Messages’ option
  6. If the selected mail folder does not contain any duplicate emails then you’ll get a popup notification for that
  7. If the folder does have duplicate emails, it will open a ‘Duplicate Messages’ window that will show you the total number of emails and the duplicate emails in the folder
  8. Click the Delete Selected to delete the selected duplicate messages. Afterwards you will receive a popup notification for that.

So this is the manual method to remove duplicate emails in Thunderbird. However, this method comes with certain drawbacks; we have listed the common ones below.

Restrictions of the Manual Method

  • The manual technique is platform dependent i.e. you must have Thunderbird email client installed and active on your system to go through with the method.
  • It requires installation on a Thunderbird add-on which makes the procedure lengthy.
  • Overall it is a technical method which requires technical knowledge. Thus, it is not suitable for most users.
  • Since it’s a technical method, a human error may corrupt all your precious data or you may suffer data loss.

All these drawbacks make the manual method lengthy and complex to execute.


In this above article, we discussed how you can solve the Thunderbird duplicate emails issue. We shared a manual solution as well as automated software to accomplish the said task. However, the manual approach comes along with some restrictions that make the whole process really complicated and risky. Therefore, to avoid all the risks and dangers regarding your vital data, technical experts recommend using the above-mentioned professional software.