I tried "Folder -> Delete Duplicate Messages" on different folders and always get the attached dialog as a result. No messages seem to have been deleted in the process. kMail 5.3.3, KDE Neon, German locale
Created attachment 102615 [details] verbose information dialog after invoking "Delete duplicate messages" I forgot to add: The account is a normal IMAP account (no DIMAP).
Git commit 0cbfe7105fb6e8d3ace091185bd10b3d7ae7c47e by Montel Laurent. Committed on 29/01/2017 at 07:43. Pushed by mlaurent into branch 'Applications/16.12'. Fix Bug 373256 - "Delete duplicate messages" feature does not work FIXED-IN: 5.4.2 M +1 -1 src/job/removeduplicatemailjob.cpp https://commits.kde.org/kmail/0cbfe7105fb6e8d3ace091185bd10b3d7ae7c47e