Google's Inbox to offer a way to take back sent email
During a Reddit Q&A that included three members of Google's Inbox team, it was disclosed that there will be a way for an Inbox user to change his/her mind, and "unsend" an email that was just sent. On the web, the Google Mail Labs channel allows the email author 10 seconds after hitting send, to change his mind and click on cancel. While nothing is written in stone, perhaps that will be similar to the way message retraction will be handled on Inbox.
Other new features coming to Inbox include support for cross-browser use, and integration with Google Drive. Also, a version for tablets is on the way. Right now, it still requires an invitation to be allowed to download the app. This way, Google can test Inbox before unleashing it on the world. The app, which is available for Android and iOS, bundles your emails together by topic, allows you to "snooze" certain emails, and generally enhances the Gmail user's experience.
source: Reddit via BGR