Nostalgy is an extension for Mozilla Thunderbird whose purpose is to save time by doing more operations with the keyboard. If you want to use Thunderbird without sacrificing the productivity you had with good old mutt/pine, this extension is for you!
Nostalgy is now hosted on Github.
There used to be a mailing list, but it is now disabled. You can always contact the author directly or post an Issue or Pull Request on Github. Acrhives of the list are available through a google group mirror.