Rated 5 out of 5 stars

Works great. Used on merging of 80K message files. To avoid the script timeout problem:

Tools -> Options -> Advanced -> General -> Config Editor... -> {Right click on} dom.max_script_run_time -> Modify -> {a longer time in seconds}

I used 500, and only had to click on the script timeout message once. I checked the Windows Task Manager, and when Thunderbird is waiting for the pause window, it stops working. Bumping up this number just prevents it from prompting for so many error messages.

This review is for a previous version of the add-on (0.3.2).