Rated 5 out of 5 stars

i use this addon for years now and didn't want to miss it.
it is extremely useful if you have a large folder structure and use "copy sent to current" addon too. with ThreadVis it is always possible to retrace a mail thread.

only drawback i found: i found no way to disable ThreadVis on "Sent" folder

This review is for a previous version of the add-on (2.1.702).