The current behavior in Drupal core when a new user registers requesting approval sends mail only to the site's contact address. Thus only one person is notified even though there may be several administrators/moderators.
This module improves this basic behavior by notifying all users that have the 'administer users' permission by default.
Administrators/moderators get a setting to disable these notifications in their user profile form. A link is also appended to each of these notifications.
Enable the module: boom, you're done.
See previous section.