Rated 5 out of 5 stars

by Charles Calvert on July 28, 2011 ·

Very useful extension, though I wish it supported more than five levels (I get some very nested conversations at times). Like jk2jxl, I was able to change the maxVersion value in the install.rdf file and install it in Thunderbird 5. See http://kb.mozillazine.org/Editing_an_add-on_to_change_its_compatibility if you want to do this.