The recent Gmail redesign is still fresh in everyone's minds and I'm still playing around with it. Google isn't done with its signature email, however. Smart Compose is the next step, which utilizes the advances in AI to improve upon the already nifty Smart Reply.
Using machine learning, Google can almost write an email for you, based on recipient(s), subject line, and a few words in the body. You just start typing and Gmail will suggest the end of your statement. Simply press tab and keep going. The machine learning can even suggest addresses and times to meet, based on the subject and body.
Smart Compose will be rolling out to Gmail users this month... as long as they're using the new design.