Rated 3 out of 5 stars

Thank you for bringing this add-on to TB - it helps greatly, especially if you need to constantly switch between multiple languages for multilingual communication. However, there seems to be an issue with this add-on - it does not allow to disable Thunderbird's spellchecker. Even though the Spelling options are switched off in Thunderbird, with this add-on ON Thunderbird underlines misspelled words in a composition window. If you uninstall this add-on all goes back to normal - no more underlines with TB's spelling OFF. Please fix this issue and I will be happy to give 5 stars :-). Otherwise this addon creates double marking for misspelled words which makes the text hard to work with.

UPDATE (29.11.2021) - Thank you for your quick reply. I've just sent all the requested details to your support email address. Looking forward to your feedback.

This review is for a previous version of the add-on (4.2.12). 

Sorry this doesn't work for you. Could you contact our support using the email you can find at https://languagetool.org/legal and send a screenshot, the TB version you use, and your operating system?