How to enable and use Gmail’s AI-powered Smart Reply and Smart Compose tools

Leading up to Gmail’s 15th birthday this week, Google has been adding a lot of productivity and machine learning tools to its email service. (It may also be trying to make up for the disappearance of its Inbox email app, but that’s an argument for another day.) New additions this week include a way for Gmail to write email subject lines for you and schedule an email to send at a later time.
Compounded with a redesign that launched last year for desktop and earlier this year on the m