I'd like to find if a particular relay was used to spam me before and have followed this advice to search through the
Thunderbird insists, no such messages exist -- even though I'm staring at one example and suspect, there are many more. I tried it both with and without the "Perform search on the server" checkbox selected (my server runs Cyrus IMAPD).
My TB is of version 60.4.0 -- did the searching subtly break without maintainers noticing, or was the advice always incorrect? How can one search for headers not on the TB's list by default?