Review for ThreadVis by Ormek
Rated 5 out of 5 stars
This is a superb AddOn. It will show me the thread of a conversation even if it is split over mutliple folders. This is great for people who, unlike me, actually still sort there emails according to projects, etc.
This addon is (apart from next-Message) my primary navigation tool.
To create your own collections, you must have a Mozilla Add-ons account.