Rated 4 out of 5 stars

by Marco A.G.Pinto on Dec. 20, 2018 · permalink

@Stewart

This add-on hasn't been maintained for several years.

The official one is now mine: "British English Dictionary (Marco Pinto)".

Please notice that Mozilla updated all Firefox spellers to WebExtensions, but they only work with Firefox 62+ due to a bug in Firefox 60ESR.

Thunderbird still uses Legacy Extensions, so you can download the version here in ATN.