Rated 5 out of 5 stars
I cannot see in pop-up menu string "Search as list" as I see in https://addons.cdn.mozilla.net/img/uploads/previews/full/122/122692.png?modified=1389758913 :(
May be it is because my Thunderbird in Russian or under Xubuntu?
That feature will be released with v2.0 which is currently under full review and should be released soon. It is not a problem with Xubuntu or your language.
If v2.0 is not released by the weekend I will try to expedite the process by having v2.0 switched to preliminary review.
Thanks for the updated rating. I am glad it now works on your Xubuntu system.