Google Blog: SUBJECT: Write emails faster with Smart Compose in Gmail – “From your greeting to your closing (and common phrases in between), Smart Compose suggests complete sentences in your emails so that you can draft them with ease. Because it operates in the background, you can write an email like you normally would, and Smart Compose will offer suggestions as you type. When you see a suggestion that you like, click the “tab” button to use it. Smart Compose helps save you time by cutting back on repetitive writing, while reducing the chance of spelling and grammatical errors. It can even suggest relevant contextual phrases. For example, if it’s Friday it may suggest “Have a great weekend!” as a closing phrase. Over the next few weeks, Smart Compose will appear in the new Gmail for consumers, and will be made available for G Suite customers in the workplace in the coming months. To get started, make sure you’ve enabled the new Gmail by going to Settings > “Try the new Gmail.” Next, go to the general tab in your settings, scroll down and enable “experimental access.” If you want to switch back, you can always uncheck the box.”
Note – This is going to cause all sorts of problems – but lots of folks will use it anyway!