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 Discourse Meta - The Official Support Forum for Discourse. 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.
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.