Done an upgrade of akonadi-database from postgres 9.6 to postgres 11 using pg_upgrade. That went fine so far, but after restart akonadi every folder had the amount of mails per folder shown as 'unread' - although *inside* the folder there were no unread mails. (workaround. set one mail to unread, change folder, go in again, set mail to read -> counter disappears) Unfortunately, after the next reboot same situation again: Amount of mails per folder is shown as unread