New sorting function for Gmail

The Gmail inbox now offers a view that shows the most important messages first. An algorithm evaluates specific properties, such as whether a user reads e-mails from a given sender and whether they respond to them. The mail can also be rated for importance manually using a new "Plus/Minus" button.

"This is an adaptive function," Google's Stefan Keuchel said. That means the "Priority Inbox" will learn over time and fine-tune itself. Messages that are rated as less important don't disappear, but simply move back into the normal inbox. Users can also return to the classic view at any time.

Google is advertising the system as one that improves efficiency. A six-month internal test showed that users needed 6 percent less time to process their e-mail messages, Keuchel said. He also provided assurances about privacy protection: information about which contacts are especially important are used by Google solely for the new function.