Article: Smart Reply isn't available for all emails; only emails to which Google can determine a sufficient response will qualify. Tap the Gmail app, which resembles a red "M" on a white background, to do so. This will open your Gmail inbox if you're logged in. If you aren't logged in, you'll need to enter your email address and password when prompted to sign in. Find an email to which you want to reply using Smart Reply, then tap the email. The email must have been sent to you. You cannot use Smart Reply to reply to your own emails. If Smart Reply is available for your selected email, you'll see several blue boxes at the bottom of the screen with various responses. Tap the option you want to use to reply to the email. Selecting a Smart Reply answer won't automatically send your email, so you can add text to the message if you like. It's a paper plane-shaped icon in the top-right corner of the screen. Doing so will send your canned response to the recipient.

What is a summary?
Understand which emails qualify for canned responses. Open Gmail. Open an email. Look for Smart Reply options. Select a Smart Reply option. Add any extra text you want to use. Tap the "Send"  icon.