Gmail Smart Labels Add Automatic Inbox Filters for Mass Mail, Combat Email Overload

What kind of mail do the Smart Labels catch? Three main categories, with one of them automatically kept out of your inbox:

* Bulk: Mass mailings, like newsletters and offerings from companies. Basically, the email equivalent of the bulk mail you get in paper form.
* Notifications: Messages sent to you directly, but automatically generated—monthly statements, bills, receipts, and updates from social services like Facebook.
* Forums: Messages from mailing lists, forums, or other groups you've joined.

Source: Gmail Smart Labels Add Automatic Inbox Filters for Mass Mail, Combat Email Overload