Created attachment 109819 [details] statusbar error message when I collect one message from my localhost and filter it into the 'logs' folder, I'm getting a duplicate message list entry and the error "unable to fetch item from backend (collection -1): unable to retrieve item from resource: [LRCONFLICT] Resource akonadi_maildir_resource_0 tries to modify item 15701 () (in collection 22) with dirty payload, aborting STORE." when I click on one of the two message list entries created. Also, automatic archival of messages now generates error messages indicating archival has failed.
Sometimes (once a week or so), I have to open akonadiconsole to delete few stray duplicates: org.kde.pim.akonadiconsole: Item fetch failed: "Unable to fetch item from backend (collection -1) : Unable to retrieve item from resource: [LRCONFLICT] Resource akonadi_maildir_resource_0 tries to modify item 233275 () (in collection 302) with dirty payload, aborting STORE." So the message is very similar to the OP. This happens only for gnu mailing lists. (e.g. Octave Maintainers List <octave-maintainers@gnu.org>), downloaded through pop3, with a filter moving the message to a dedicated subfolder (research/soft/octave/)
After adding a filter: - match all messages - Executed Command: /usr/bin/sleep 1, no duplicates for months. (on openSUSE Leap-15.0) This is only a workaround, and maybe a clue to find what's going on.
Confirmed with KMail 5.10.3 shipped with openSUSE Leap-15.1: After disabling the delay filter described in comment #2, it took only a few days to get Unable to fetch item from backend (collection -1) : Unable to retrieve item from resource: [LRCONFLICT] Resource akonadi_maildir_resource_0 tries to modify item 107263 () (in collection 53) with dirty payload, aborting STORE. Again that came from a gnu mailing list (https://lists.gnu.org/mailman/listinfo/texmacs-dev)
May this be a dupe from https://bugs.kde.org/show_bug.cgi?id=389829 ?