I've located an addon which may work for you. * https://addons.mozilla.org/en-us/thunderbird/addon/quick-translator/?src=hp-dl-mostpopular Download addon to desktop how to install: In Thunderbird Tools > Addons OR menu icon > addons clickon gear wheel icon and select 'Install addon from file' locate the file you downloaded and click on 'Open' When installed it will appear in Addons Manager. You may need to restart Thunderbird.