Worked fine Rated 4 out of 5 stars
Usig Firefox 26.0, I copied half a dozen folders one at a time and it copied those along with their subfolders. Some subfolders also had subfolders. All folders and subfolders and emails copied. There were over 40 folders and 2,000 emails in total.This review is for a previous version of the add-on (1.5).