Google just announced that they will be rolling out some changes to their inbox over the next couple of weeks.
The new features give users quick action buttons on certain emails like transactional, invites and calendar reminders, that will allow users to take action on that mail without ever opening the message.
Please keep in mind that this is designed for transactional mail, not bulk marketing mail. However, for the email marketer that wishes to take advantage of this feature they will need to Register their sending address here – https://developers.google.com/gmail/schemas/registering-with-google
and follow the instructions to implement here – https://developers.google.com/gmail/schemas/.