Rated 5 out of 5 stars
Very useful to keep hands on the keyboard while browsing mailboxes, moving and copying messages. It Worked flawlessly up to Thunderbird 60.* .
After migrating to Thunderbird v68.4.1 (Debian buster v10.2), I had to remove it.
I haven't tried yet the new nostalgy-xpi . Meanwhile replaced "Nostalgy" with "Quick Folder Move".