Hello, for turning on improved_mboxlist_sort I turned off cyrus imap, called `ctl_mboxlist -d > FILE`, renamed mailboxes.db to mailboxes.db2, switched in imapd.conf 'improved_mboxlist_sort:1', and called `ctl_mboxlist -u < FILE`, cf https://www.cyrusimap.org/imap/developer/thoughts/improved_mboxlist_sort.html .
This created a new mailboxes.db file, which is 2.33 times smaller, that the original (renamed). The database format is twoskip. Converting both the old and new mailboxes.db to flat with $cvt_cyrusdb MAILBOXES.dbX twoskip MM flat and comparing the results, the old file contains user.ttt.#addressbooks.MMM %(A %(ttt lrswipkxtecdan) I a0ab91ff- 6de8-4961-b9cf-646b8037e87a P default T a V 1562330471 F 674 M 1599389319) whereas the new file contains user.ttt.#addressbooks.MMM %(A %(ttt lrswipkxtecdan) P default T a M 1601752550) The fields: I a0ab91ff-6de8-4961-b9cf-646b8037e87a V 1562330471 F 674 are missing from the new file. Shall I be worried? Greetings Дилян