Is there a way to set up to get an email if any post is made to a particular category?
Yes, in your preferences. Here in Meta, that would be at https://meta.discourse.org/my/preferences/categories. Add the particular category to Watched. If you have not been active on the site for ten minutes, you should get an email notification for any new post.
I thought that but it is not working for me.
Does notified mean send an email?
Out of the box, notification emails are only sent if the user’s web browser hasn’t been seen by the website in 10+ minutes. You can adjust this in your user preferences.