One thing I need to do is move the email generation code to its own template. It's currently on the test page where I try different things before making them live. I don't want to trigger multiple emails each time I forget and go to work on something else.
As with the custom RSS feeds, it's not something I anticipate anyone actually signing up for. I just thought it was worth a shot at creating as much for the intellectual exercise than the functionality.
Maybe, in future, I could hook into it to send additional mails or a newsletter and have it all self-hosted rather than relying on a third party service like Mail Chimp.