Rated 5 out of 5 stars

I really like this extension. It does exactly what I need. I tend to be a "mail hoarder" and I move everything from my Gmail accounts to my Fastmail account in T-bird. It's far easier--at least for me--to drag an email up rather than to the folders on the left. Also, I have a great deal of respect for the fact that the updates are a regular thing. It means that it's constantly being improved on. Well worth the cost!

This review is for a previous version of the add-on (5.12). 

Thanks for your kind words. I am still ironing out some kinks with performance, some users have a hard time with Tb 102 - there is also a fix from Thunderbird itself in 102.2 coming soon!