Rated 4 out of 5 stars
The only missing item I see is the Grouped By Sort bars. View -> Sort By -> Grouped By Sort.This review is for a previous version of the add-on (1.6).
Thank you for a report.
Because the appearance of original LeopardMail was lost when I included the function by all means, I took off a function.
Please expect it in new Thunderbird 3.