Rated 4 out of 5 stars

Από τον/την Martijn στις Μάρτιος 10, 2009 · μόνιμος σύνδεσμος

Works well. I used it to separate 3000 duplicates from 200 actual messages. Thunderbird had created these due to some bug.

Although the UI isn't very intuitive, it does what it claims to do, and pretty fast as well.