Developer reply by GS! Networks
Rated 2 out of 5 stars
Does not work in Postbox Express as advertised.
This review is for a previous version of the add-on (3.3.1).It only works in Postbox Pro. Express has missing interfaces that ThunderBrowse needs (or so I heard [I only have Pro on my test machines]).
To create your own collections, you must have a Mozilla Add-ons account.