Remove Duplicate Messages

Wurdearring: 3 fan de 5 stjerren

troch itechniker op June 30, 2025 · permalink

Thunderbird version: 139.0.2 (Windows)
Use case: IMAP mailbox with many subfolders
Additional enabled option: Comparing messages - recipient, folder

Bug
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When I search for duplicates, the add-on finds many (X duplicates across various folders). If I then want to permanently delete all of them, the add-on asks whether to delete X duplicates from folder Y (Y being the folder of the first found duplicate). This question is misleading.

If I click “Yes,” Thunderbird shows the message “Z items deleted in folder Y” in the activity log – which is definitely too many items for that folder (not X, but clearly more than the actual number of duplicates in that folder).

Another bug
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(also mentioned in some reviews, though users often didn’t realize they were using the add-on incorrectly):

If you right-click on a folder, the add-on does not search for duplicates in that folder. Instead, it always searches the last selected/active folder – which can lead to confusion or mistakes if you're not aware of this behavior.

Also
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Selecting duplicates is very impractical when you have many across different folders. It’s not possible to select multiple duplicate groups and, for example, apply "keep first" or "keep last" just to those selected groups – these options can only be applied to all found duplicate groups at once.

Because of that, the add-on is hardly usable if you have many folders and want to search across them flexibly.