Yesterday, we had a discussion about the integration of Google Contacts with Google+. Now, it is latest that even Gmail has added so many features to share the files in Google+ very easily. You can add new people to your circles and find messages from the circles.
Though there are complaints that finding the sent and received messages by the members of group isn’t possible, you can restrict the messages to a circle. Now, you can view list of circles below to the labels and you can use it to find mail from your family, friends, colleagues etc.