Kinda working Rated 4 out of 5 stars

Very useful, however its accuracy in detect dupes is not perfect (it miss just a few ones) and seems not possible to delete dupes in personal IMAP folders (you've to move them in a local folder > search for dupes > put back in imap folder).

Works but with some limitations Rated 4 out of 5 stars

1. The documentation needs a lot of improvement. I had to search reviews to discover features. Getting to utility options was not obvious (For example: I had no idea the Sent folder was disabled until a review sent me to the Options). Anyway...
The program worked fine for other folders but the duplicates were initially left in place on the Sent folder despite a whole search and dialog being generated. I told it to Delete Selected but nothing happened that I could see. There was no indication I could see of anything like a count down happening which would have told me to wait. I gave up, and restarted TB when I discovered to my amazement that the duplicates were in fact gone.
Win 10 64 bit, Thunderbird 45.5.0, Most recent Add-on as of November 2016. TB says there were 21,000+ messages in Sent but the Add-on reported a few hundred fewer. This made me apprehensive though it may not mean anything.

This is a combination of a review and some bug reports...

Could you please file these bugs, separately, on ?

As for the documentation, I guess it could be clarified more, or I should possibly indicate in the dialog that special folders were skipped.

Not really usefull and not always detecting duplicates Rated 2 out of 5 stars

Nice to have such ad-dons, but it should works automatically on new mails received, otherwise it's useless.
I also can't get it works 100% with 45.4, it doesn't detect some duplicates.

Topp Rated 5 out of 5 stars

Großes Kino, genau hiernach habe ich gesucht! Funktioniert 1A, wo mich zahlreiche Alternativen - Datei- oder Outlookbasiert - im Stich gelassen haben. 1000 Dank.

Thanks, works just fine!

Failed to function Rated 1 out of 5 stars

Would not work, on Thunderbird v24.6.0 Starts just fine, but then never does anything. No error messages, no screen appears, nothing. I only saw searching for duplicates in the status bar, but even letting it run for hours...nothing ever happened.

works great on 45.2 Rated 5 out of 5 stars

Works great on 45.2, thanks for making this tool, you are saving many people from the plague of duplicated IMAP messages...

Замечательно Rated 5 out of 5 stars

Прекрасно справляется, ищет дубликаты сразу во всех подкаталогах, очень удобно.

Ende einer qualvollen Zeit - dank diesem Add-On Rated 5 out of 5 stars

Über Jahre hinweg nervte mich Thunderbird mit doppelten Emails. Erst jetzt bin ich auf die Idee gekommen, dass jemand vllt. bereits eine Lösung für dieses teschnische Problem programmiert hat. Und ja, es gibt sie mit diesem Add-On. Es funktioniert einwandfrei und auf einen Klick, ohne Wartezeiten.

Innovative, significant time saving app Rated 5 out of 5 stars

Works like a charm. Sends duplicates to Trash. Show on trash with a delay, but that's okay once you know.

Wonderful Rated 5 out of 5 stars

Great UI. Great reliability. Works just like I'd design it to -- even better, probably. One of the better Thunderbird add-ons I've used.

Thank you for your kind words. I'm glad that you found it pleasing both as a user and a developer.

Excellent add-on , but two questions Rated 5 out of 5 stars

I just installed this add-on and it does exactly what I wanted. Thank you.

I have two questions. Firstly, what does the menu entry with the very long name actually do? The only difference I can see is that the next time (ond only that one time) I select "Remove Duplicates ..." I see a pop-up saying "not checking special folders".

And secondly, why are so many comparison options needed? Isn't it sufficient to just compare on comparing the message-id and date headers? (That is what my other mail client does, and I have always found it sufficient.)


1. It means that in your next dupe search, only dupes of messages found in the folder(s) you marked as "originals folders" will come up.

For example, suppose you have folders F1 with messages m1, m2 and folder F2 with messages m4, m5, m6. Assume that m1=m4 and m5=m6. If you don't set originals folders, and search for dupes in F1 and F2 together, you'll get two dupe sets: { {m1,m4}, {m5,m6} } ; but if F1 is the "originals folder", you'll only get { {m1,m4} } .

2. Different people want to use different comparison criteria. Your suggestion is sufficient for your use case... if someone sent you the same message, once via a mailing list and a second time directly, the message ID will probably be different, and the date also (well, date received anyway). So - you would need other criteria for this scenario.

Thanks for the positive review.

Excellent tool Rated 5 out of 5 stars

I can finally suppress those nasty doubles!

The add-on is simple to use and efficient. However, I suggest adding a "do the same for all folders" option when suppressing messages to go faster: I have many folders, and having to confirm the suppression for each of them is kind of a pain. This option would make the add-on complete!

Rated 5 out of 5 stars

This add-on is extremely helpful when you end up with duplicate messages in your mailbox (for example as a consequence of communication problems between Thunderbird and an IMAP server). Straight forward and quick.

Works well, but needs some tidying up to be somethign you can keep. Rated 3 out of 5 stars

This add-on adds a ridiculously long option to the right click and Tools menus so it needed removing as soon as I had used it. This may be why I removed it last time I used it.

For removing duplicates it works well.

Couple of minor annoyances which I found while I had it installed (for less than 5 minutes due to the above), telling it to search special folders gives you an error about not searching special folders, which is set in the global options. I can understand the behaviour if you were selecting the root of the account and searching everything but it shouldn't do this if you are specifically selecting a special folder only.

Once you have searched for duplicate messages and you select delete on the duplicate messages window you get a pop up confirmation. If you select cancel rather than dropping you back to the results window it just cancels the whole process and you have to start again.

This review is for a previous version of the add-on (0.3.10). 

Some replies

* About the cancel-cancels-everything - you're right, it shouldn't work that way. I opened a bug and will fix it:

* About the long right-click menu item: I'm not too happy with it myself, but - can you suggest something shorter? I don't want it to be cryptic and confusing.

* About the special folders restriction: In this case I have to respectfully disagree. You need to remember that user error with this extension can lead to Data Loss; as a result, I have to "err on the side of caution" - I remember the cases of people complaining about accidentally deleting messages from Sent / Drafts / etc.

Anyway, thanks for taking the time to write a detailed review.

重複メッセージの処理(削除)から解放される最良のアイテムとして、推奨します。 Rated 5 out of 5 stars

簡単です。そして、確実(Perfect )に機能します。

(同様な機能を提供する「Remove Duplicate Messages」を使用をしていたが・・・)、この「Remove Duplicate Messages (Alternate)」では、①削除前に検索結果を表示できるうえ、②default 設定で、(重複メッセージの処理を)「完全削除」と「ゴミ箱へ移動」の二択から選択することができるので、(不意な削除を防止でき)安心です。③しかも IMAP and RSS accounts も管理ができるので万能です。


This review is for a previous version of the add-on (0.3.10). 

Rated 5 out of 5 stars

Very useful extension but beta version 0.3.11b is required for all functions to work in current Thunderbird version.

This review is for a previous version of the add-on (0.3.10). 

Great addon, but stopped working for TB 31 Rated 5 out of 5 stars

Thanks eyalroz for this very useful addon. It seems to have stopped working in the latest updated of TB - 31.

This review is for a previous version of the add-on (0.3.9). 

Fixed in 0.3.10b

Fixed - please check the beta.

Seems to have stopped working in TB 31.0 Rated 4 out of 5 stars

Great addon, but doesn't find anything since I upgraded to TB 31.0
Edit: Dev version doesn't work either

This review is for a previous version of the add-on (0.3.9). 

Fixed in 0.3.10b

Fixed - please try the beta

Geweldige add on Spaart heel veel tijd Rated 5 out of 5 stars

Ik had wat zitten rommelen en had honderden dubbele mails. In eer minuten weggewerkt!

This review is for a previous version of the add-on (0.3.9). 

Rated 5 out of 5 stars

2001 duplicated mails deleted :-D
Thanks a lot! I can't recommend this addon enough!

This review is for a previous version of the add-on (0.3.9).