After restarting kmail and akonadi from scratch (after deleting all akonadi data and kmail settings), the subfolders of "Local folders" are no longer translated. STEPS TO REPRODUCE remove .config/akonadi/* remove .local/share/akonadi/* remove kmail settings Alternatively, you can create a new user and start kmail. OBSERVED RESULT Even though using German locale, the subfolders of "local folders" have English names. EXPECTED RESULT The names should be localized. That has been the case until recently. SOFTWARE/OS VERSIONS Linux/KDE Plasma: openSuse Tumbleweed KDE Plasma Version: 5.15.3 KDE Frameworks Version: 5.56.0 Qt Version: 5.12.2
After some more investigation, I think I came a bit closer to the actual root cause. After looking into the akonadi_db with akonadiconsole, in particular on collectionitemtable, I found that each mail folder has a property called ENTITYDISPLAY which should contain its localized name, t.ex. ENTITYDISPLAY ("Posteingang" "mail-folder-inbox" "" ()) for the inbox in German. However, in my case the property was missing for the inbox folder and for the other local folders it contained the English names only. Seems to be an initialisation problem of akonadi. This would also explain why you never see the problem with existing akonadi databases as the property was correctly created in the past.