Tutorial for using Discourse over Email?

Yes, it is supported. The relevant setting is called Enable mailing list mode and it’s in user settings under the email tab (forum.example.com/u/my/preferences/emails).

Once that setting is active, a user will get an email for every new post on the site and can reply via email.

Has anyone any tips on the Discourse administrative setup side, and a tutorial that we can adapt to teach people how to customize their own settings?

I don’t believe we have a guide for admins or a tutorial for customizing settings. Once it’s set up there isn’t a whole lot to configure.

The most important thing for an admin to do is ensure reply via email is configured correctly: Configuring Reply via Email ✉

For users, I think one of the most frequently asked questions is how to only get email from specific categories. To accomplish this, someone can visit the page for an individual category (e.g., https://meta.discourse.org/c/installation) and mute the category from the tracking menu (circled below). People with mailing list mode enabled will not get emails from muted categories.