Disable these notifications in wp-admin/ms-options.php when new users register and creates sites

I just set up BP in WP 3.0 multisite using Social theme. Whenever I create a new test user and set up test sites, I get an email saying to:

“Disable these notifications: in http://my-domain-name/wp-admin/ms-options.php”

Is there anything to disable or is that just a notice to let me know that someone has either registered or created a new site?