¿Cómo restringir que usuarios anónimos publiquen en categorías específicas en Discourse?

So if I am understanding correctly the anonymous users are replying/creating topics by email?

In Category Settings Tab there is setting for email posts. I can’t see the options as I do not have reply by email setup. Here is a pic

I am guessing you might be able to set it here whether or not a reply/post can be done by email maybe.