Gmail introduced quick action buttons that are placed next to the subject line in a list of messages. "These buttons appear next to certain types of messages in your inbox and let you take action on an email without ever having to open it. For example, you can RSVP to your friend's party invitation or rate that restaurant you went to last night all right from the inbox. You'll be checking things off that to-do list in no time."
For flight notifications, Gmail has a special card displayed above the message that includes real-time information about the flight and a "check-in" button.
Google detects the type of message and tries to extract the most important action, but you can help Google by adding schema.org markup to the mail you're sending. Right now, Gmail support 4 quick actions (invitations, reviews, one-click actions and links to other pages) and one interactive card (flights). Now that Google includes Gmail results in Google search (Field Trial) and uses Gmail data to show Google Now notifications, the structured markup is even more useful.
Gmail actions "will roll out over the next few weeks" and I'm sure this will be a very useful addition to Google Apps for Business. What kind of quick actions and interactive cards would you like to see?