VERY helpful, although unstable with very large folders Rated 4 out of 5 stars
This was a lifesaver for me. I had a mailbox with 60,000 messages in it, about 10,000 of which were duplicates. This tool solved all my problems.
I ran it once on a mailbox without about 30,000 messages, and it worked flawlessly after I clicked through a "stopped script" dialog.
It ran less smoothly on the mailbox with 60K messages...it hung up and then crashed (exited) Thunderbird. But, I restarted the system and re-installed the extension and it worked...as long as I clicked through a bunch of "stopped script" dialogs and then ultimately clicked "stop", which dropped me into the review dialog. I then moved to trash, rather deleting outright, because deleting outright had also crashed Thunderbird.
All that said, I am so grateful for this tool. I didn't expect it to be able to process 60K messages at all, so the fact that I was able to get through it with just a few hiccups was a relief.
About that crash...