Fix Thunderbird Sending Duplicate Emails with Top Methods

Thunderbird sending duplicate emails is a surprisingly common problem. It usually does not mean that something is seriously broken but in most of the cases, the issue is caused by account configuration conflicts, server synchronization problem, or add-on interface.

If you have ever clicked on “Send” in Thunderbird, felt confident that your message is on its way but on the other hand the recipient received that message twice or more. This can be frustrating and especially when you communicate professionally where duplicate messages may look careless and like spam.

Reasons Thunderbird Sending Duplicate Emails Frequently

Thunderbird may send emails twice or more than that due to multiple reasons and some of them are listed below:

• Server Sync Issue: Improper synchronization with the email server can result in Thunderbird sending duplicate emails multiple times. This issue usually happens when the server’s message UID changes, making Thunderbird treat existing messages as new.
• IMAP Folder Corruption: Corruption in IMAP folders-either on the server or within the local folder of Thunderbird, it can disrupt synchronization and result in sending and receiving duplicate messages.
• Filter Misconfiguration: Incorrectly configured filters or rules may repeatedly process outgoing messages, unintentionally triggers the issue of Thunderbird double emails frequently.
• Multiple Account Configurations: Sometimes when a user is using multiple accounts with shared or mismanaged SMTP settings, it can lead to emails being sent from the wrong account that results in duplicates.
• Add-Ons or Extensions Interface: Faulty or outdated Thunderbird add-ons can interfere with the email handling and cause double and more messages.
• Incorrect SMTP Server Settings: Improper SMTP configuration, such as wrong ports or authentication methods may prevent delivery confirmation and cause Thunderbird to resend emails that have been already sent once.
• Send Later or Outbox Issue: Emails scheduled with send later or stuck in the outbox folder may be sent multiple times, especially after connectivity interruptions.
• Duplicate Emails from Imported MBOX Files: Importing MBOX files that already contain duplicate emails can introduce clutter and contribute to ongoing duplicate issue in Thunderbird emails client.

1: Disable Place a Copy in Sent Folder

1. Start Thunderbird email client on your system.
2. After that, choose Tools >> Account Settings.
3. Now, select the Copies & Folders button.
4. Uncheck Place a copy in the Sent Folder.
5. After that, restart Thunderbird and check for problems.

2: Check Server Settings

1. First open Thunderbird on your computer.
2. Now, select Tools >> Account Settings option.
3. Choose the Server Settings option to proceed.
4. Make sure that you have used the correct server settings such as Server Type, Server Name, Users Name, Port Number etc.

3: Reconfigure Thunderbird Profile

1. First go to Thunderbird’s profile storage location and create a Thunderbird backup.
2. Now, choose Thunderbird Account Settings >> Account Actions.
3. Click on the Remove Account button to delete the already configured profiles.
4. After this, again choose Thunderbird Account Settings >> Account Actions.
5. Thereafter, select name, email address and password.
6. Click on the Continue button to proceed further.
7. Configuration found in Mozilla ISP database and click on Done.
8. Later you can Import backed-up data if required.

4: Delete Thunderbird POPSTATE.DAT File

Thunderbird creates a popstate.dat file when users configure your email account using POP settings. Its main function is to retain the status of messages that Thunderbird has fetched from the POP server and retained there. Sometimes this popstate.dat file gets corrupted for several reasons. At this time, users need to re-create the popstate.dat file to resolve Thunderbird sending duplicate emails. Below are the following steps for recreating the popstate.dat file automatically.

1. Firstly, close Thunderbird completely and ensure hidden files view is enabled.
2. Now, navigate to the Thunderbird profile storage location and open the Mail folder.
3. After this, explore the Local Folders and delete the popstate.dat file.
4. At last start Thunderbird client for recreating the popstate.dat file automatically.

Still Thunderbird Sending Duplicate Emails?

If you are still struggling with Thunderbird double emails? You need to get your hands on some good technique that may help you to fix Thunderbird sending duplicate emails efficiently. If the above mentioned fixes do not work or benefit you temporarily, you can just switch to another email client and backup Thunderbird data entirely before that.

Quick Steps to Solve Thunderbird Sends Email Twice

1. Initiate with downloading the solution on your system.
2. After that, choose an option to connect it with the Thunderbird account data.
3. Now, preview the entire Thunderbird profile data that you have connected.
4. Unselect any file or folder that is not required to save in the storage.
5. Now, choose a format to save entire data into storage or email client to directly migrate your data.
   
6. In the last step choose a destination path and click on Next button to complete the process.
   

Once the process is completed you can access Thunderbird data into Gmail, Outlook, and multiple other email platforms. Even if you don’t move your Thunderbird data to any platform, you can just download them into various formats and save them as a backup of important data.

What Else Does this Professional Solution Offer?

• This professional solution protects data from any corruption and loss.
• Offers quick and safest steps to complete the process, saves time & effort.
• Maintains originality and hierarchy of the entire data safely.
• Allows users to even download all attachments from Thunderbird emails safely.
• Fixes Thunderbird sending duplicate emails by making a secure backup.

Ensuring Clean, Consistent, and Reliable Email Sending

We discussed some very good methods to solve Thunderbird sending duplicate emails with safety. Sometimes users get stuck with manual techniques and also sometimes these manual methods do not work. Therefore, we have discussed professional solutions as well so that it is easy for the users to stop Thunderbird sending email twice or more.