Feeling overwhelmed by the amount of email in your inbox? There are some pretty clever solutions designed by Google to help you manage the flow of email to your inbox and tools to help you make sure your attention is focused on the email that is most important to you. One such "Lab" is SmartLabels, which automatically categorizes incoming Bulk, Notification or Forum messages.
Google's Tips & Tricks document to help you to Reduce Inbox bloat with SmartLabels outlines this features and and provides steps to help you set up your inbox.
Please note that that SmartLabels is a Lab feature. If you decide to use Labs, keep in mind about these features may break or even disappear at any time as they are in an experimental phase of deployment. See Google's information online if you would like to learn more about Labs.