The Quick Filter is extremely slow on version 128.1.0esr (and also on 128.0.1). There is a thread about it on reddit. https://www.reddit.com/r/Thunderbird/comments/1e6hryp/quick_filter_is_super_slow_in_128/ There was a bug reported, and it is listed as closed (solved). When will this bug fix show up in the release version? Or how do I put in a patch? Thunderbird is almost useless for me with this problem. Here is the bug report thread: https://bugzilla.mozilla.org/show_bug.cgi?id=1908761 Thanks for you help.