For historic reasons (25 years of use :/ ) I view messages in each mailbox by date, ascending, unthreaded. I'm currently using v.102.2.2 (64 bit) on Ubuntu 20.04. The global setting of view - > sort -> threaded has just switched on all by itself, bit annoying because at first I thought all sorts of messages had been deleted... I can change to "unthreaded" on a mailbox by mailbox basis except that I have 14,000-odd mailboxes. I have changed the global settings using: Edit -> settings -> scroll down, clock on "config editor" button Edit "mailnews.default" Set: mailnews.default_news_sort_order 1 (ascending) mailnews.default_news_sort_type 18 (sort on date) mailnews.default_sort_order 1 (ascending) mailnews.default_sort_type 18 (sort on date) except that although mailnews.default_news_sort_type was set to 22 (threaded) and I have changed it to 18 on a stable basis (it stays at 18) I never use news and so the value for mailnews.default_sort_type was 18 all along.. and the global sort setting (found by looking at a random mailbox) is still set to "threaded" - as if "mailnews.default_sort_type" is not being read. Ideas?