I recently updated my Thunderbird client to v115.0b6 (on a 2012 Macbook Pro with Mac OS 10.14), and as so many apps nowadays, it has become worse instead of better: - There is a large margin on the left side of the subject column in the email list which wastes a lot of space. How can I hide it? - Performance is worse: The update of the mailing list and the spam filtering is significantly slower than before. Often takes a second for 2-3 items. Why should an update with basically the same functionality ever become slower? - The issue that external images are never shown to me even after I have allowed external contents to be shown is still not solved.

As far as I remember, going back to a stable (non-beta) and more performant version (where the last issue shouldn't exist) is complicated due to database migration. Probably someone can help me accomplish this anyway.