The comments module provides snippets to allow visitors to comment on almost any piece of content within the site and optionally set a rating for the content e.g. 4 out of 5.
From the dashboard select Settings and then the Comments settings folder, from here you can set the email address notified of new comments/reviews. If you are using the HipChat module then you can also set the notification service level so that new comment notifications also appear within this service.