This code disables the automatic email sent to the blog admin each time a new user creates an account.
This plugin replaces the default wp_new_user_notification, the function that is called when a new user signs up. Typically, the code sends an email to the administrator. My code modifies the function so no email is sent. No other functionality is lost. The only purpose of this plugin is to prevent the new user notification emails. I wrote this plugin because I needed it for one of my sites that gets a few new users each day.