Thunderbird: Remove Duplicate Mails

Martin Brinkmann
Dec 17, 2007
Updated • Jun 26, 2017
Email, Thunderbird
|
6

Remove Duplicate Messages is a Thunderbird extension that scans Thunderbird's email storage to find and fix duplicate messages.

Duplicate mails can be a problem even in the most advanced or modern email application. It does not matter if you use Outlook, Thunderbird, a web mail service, or a self coded mail program, duplicate mails can be a problem in each program.

This can happen for instance if you merge folders in a mail program or if a server error or download error results in multiple downloads of the same email from the mail server.

Remove Duplicate Messages

remove duplicate emails thunderbird

The Remove Duplicate Messages extension for Thunderbird provides you with options to remove those duplicate messages in the mail client.

Just right-click a folder in Thunderbird after installation of the extension and choose Remove Duplicate Messages from the context menu. Mails can be sorted by information such as sender, messageid or subject.

A test run on my main computer had the result that it did show more than 1000 duplicate messages. I thought that this was an error at first but it was not. The extension marks one mail with the keep flag and all other mails that are duplicates of it with the DEL flag.

A left click on a mail opens the containing folder of it, a right-click a small popup window with the most important details of the selected mail.

Oh, and guess what. Deleting those 1000 mails reduced the size of all mailboxes by more than 60 Megabytes.

You may want to open the preferences of the extension after installation first, as you can configure several important features there.

The main settings tab for instance lists all the parameters that the program uses to find duplicate email messages in Thunderbird. That's the message ID, the data in seconds, the subject and the from address.

You can add more parameters there, or remove existing ones. The additional parameters made available are date, line count, message body and the to address. The author notes that the scanning slows down if the message body comparison option is enabled in the preferences.

The second settings tab lists additional options. Here you can define which email you prefer to be deleted, e.g. the first found email, the larger or smaller email, or unread or unanswered amils.

While I would not recommend using it, it is possible to enable auto delete here so that duplicate emails get deleted by the program automatically. This can work out well if you limit the comparison metrics to message ID for example, but is generally not advised.

Verdict

Remove Duplicate Messages is a useful extension for Mozilla Thunderbird that enables you to scan mailboxes to find and deal with duplicate messages.

Summary
software image
Author Rating
1star1star1star1stargray
no rating based on 0 votes
Software Name
Remove Duplicate Messages
Software Category
Email
Landing Page
Advertisement

Tutorials & Tips


Previous Post: «
Next Post: «

Comments

  1. JMGG said on January 19, 2012 at 8:25 am
    Reply

    You said that Outlook isn’t your main email client, so which is your main one?

    1. BalaC said on January 19, 2012 at 9:42 am
      Reply

      I think its thunderbird

    2. Martin Brinkmann said on January 19, 2012 at 10:15 am
      Reply

      It is Mozilla Thunderbird.

  2. Salaam said on September 24, 2012 at 9:52 pm
    Reply

    Awesome! This actually solved my problem… what a stupid bug.

  3. Claud said on December 19, 2012 at 2:08 am
    Reply

    If this is the same bug that I’ve encountered, there may be another fix: (1) hover over open Outlook item in Taskbar, cursor up to hover over Outlook window item, and right-click; (2) this should give you Restore / Move / Size / Minimize / Maximize — choose Move or Size; (3) use your cursor keys, going arbitrarily N/S/E/W, to try to move or size the Outlook window back into view. Basically, the app behaves as though it were open in a 0x0 window, or at a location that’s offscreen, and this will frequently work to resize and/or move the window. Don’t forget to close while resized/moved, so that Outlook remembers the size/position for next time.

    1. Lynda said on February 12, 2013 at 3:37 pm
      Reply

      THANK YOU Claude!!! I could get the main window to launch but could not get any other message window to show on the desktop. You are my hero!!!!

    2. Chad said on November 20, 2018 at 4:24 pm
      Reply

      Solved my issue! 6 years later and this is still problem…

    3. Ivan X said on January 21, 2021 at 4:50 pm
      Reply

      Fantastic. Thank you. Size did the trick.

  4. Andrew said on October 26, 2013 at 7:06 am
    Reply

    This solved my Outlook problem, too. Thank you. :)

  5. Charles said on December 7, 2013 at 7:23 pm
    Reply

    Thank you so much, this started happening to me today and was causing big problems. You are a life saver, I hope I can help you in some way some day.

  6. garth said on November 7, 2014 at 7:13 pm
    Reply

    You are a god – thank you!

  7. Faisal said on February 9, 2015 at 10:09 am
    Reply

    thanks a lot…. work like charm.. :-)

  8. Simon said on March 24, 2015 at 11:36 pm
    Reply

    Yah…thanks Claude. I’ve been having the same problem and tried all the suggestions…your solution was the answer. It had resized itself to a 0/0 box. Cheers

  9. Olu said on April 14, 2015 at 1:35 pm
    Reply

    Excellent post. This had me baffled even trying to accurately describe the problem. This fixed it for me.
    Thank you

  10. Coenig said on July 23, 2015 at 7:36 am
    Reply

    Thanks a lot for the article. Don’t know why it happenend, don’t know how it got fixed, but it was really annoying and now it works :-)

  11. Fali said on January 20, 2016 at 4:19 pm
    Reply

    Thanks a lot. I was facing this issue from past 3 week. I tried everything but no resolution. The issue was happening intermittently and mainly when I was changing the display of screen ( as i use 2 monitors). The only option i had was to do system restore. But thanks to you.

    1. MIki said on January 10, 2019 at 11:54 am
      Reply

      I’ve been tried to sole this problem for 12hours. Your comment about changing the display of screen helped me a lot!! Thanks!!

  12. Christina said on January 20, 2016 at 6:14 pm
    Reply

    Thank you…don’t know why this happened but your instructions helped me fix it. Running Windows 10 and office pro 2007

  13. Oz said on July 22, 2016 at 3:20 pm
    Reply

    Great tip! Thanks!

  14. Tracy said on September 1, 2016 at 4:48 pm
    Reply

    Worked for me, too – thank you!!!

  15. shawn said on September 9, 2016 at 10:25 am
    Reply

    It’s Worked for me, too
    thank you very much!

  16. Jari said on October 31, 2016 at 11:53 am
    Reply

    I had a similar issue with Outlook 2013 on Windows 10 and this helped me to fix it. Thank you very much!

  17. Michel H said on November 30, 2016 at 11:08 pm
    Reply

    Thank you so much. Solved!
    Considering you published this in 2012, incredible not been debugged by Microsoft.
    Thank you again. M

  18. Ziad Bitar said on January 9, 2017 at 2:00 am
    Reply

    This problem was faced by only one user logging to TS 2008 r2 using outlook 2010.The issue was resolved.

    Thanks.

  19. Anonymous said on February 15, 2017 at 5:24 pm
    Reply

    Great tip. Thank you!!!! If it helps, I had to use the Control Key and the arrow keys at the same time to bring my window back into view. Worked like a charm.

  20. Rochelle said on March 6, 2017 at 11:59 am
    Reply

    Thank you, this worked !!!!

  21. anom1234 said on May 20, 2018 at 11:20 pm
    Reply

    Man, you are a fucking god. Thanks a lot, what an annoying bug!!

  22. JC said on October 12, 2020 at 2:14 pm
    Reply

    Awesome, this post solved the issue. Many thanks!

Leave a Reply

Check the box to consent to your data being stored in line with the guidelines set out in our privacy policy

We love comments and welcome thoughtful and civilized discussion. Rudeness and personal attacks will not be tolerated. Please stay on-topic.
Please note that your comment may not appear immediately after you post it.