MOUNTAIN VIEW, Calif. — A decade ago, Google took the wraps off Gmail, the popular e-mail service used by hundreds of millions the world over. Now that e-mail is vibrating in pockets as often as it’s pinging computers, the Internet giant is rethinking how your inbox should look and work. The result is Inbox, a new product that Google says is a smarter way to sort e-mail. It’s rolling out Wednesday by invitation only. “We want this to be your inbox for the next 10 years,” Alex Gawley, product director of Gmail and Inbox, said in an interview.