Welcome to Thunderbird Add-ons.
Add extra features and styles to make Thunderbird your own.Tutup
Rated 5 out of 5 stars
Very nice. On the web, there are too many small forms, so they often annoy me. This is very easy to use - only doing drag-and-grab edges of those forms.
I recommend this for any people. I think this should be a standard feature of Firefox.