Cannot toggle off Spellcheck in Mail 12.4

I detest the intrusion of spellcheck with popup suggestions and red underlining of proper nouns. So I toggled it to Never in Mail preferences. But it continues, even when I switch the setting, restart, switch back to Never, and restart again. I'm also getting the intrusion while using Safari in this post.

Is there another setting I can use to get rid of it? Or perhaps some programmer at Apple took a shortcut in this version of Mail and "forgot" to make spellcheck optional?