We seem to have fixed the problem with Chris & Tess not getting emails from the system.
I removed Chris as a Site member (thoroughly this time) and he signed up again. And they are now receiving emails sent to their personal email address.
I've also made a couple of improvements: 1. to close the Preview page you can now click anywhere in the page to return to your previous screen 2. when you have entered a Subject for your email, then the Title field auto-completes with a copy of the Subject. You can of course edit the Title, or, if you do not want a title at all, just type a space.