Gmail Smart Reply, is a new feature which may as will save you from typing replies to mails which arrive in your inbox. This is a new prediction system, which generates a response based on the content of the email.
These Smart Replies are available for Android and iOS, and appear at the end of the original email, in boxes. These suggestions are similar to the ones in Google Inbox. If you are familiar with Inbox's smart replies, you should probably know that they are not 100% the best choice, as sometimes the predictions are off.
For example: Let's say someone sent you an email asking if you have finished work on something. The Smart Reply auto response will be like "Yes. I am working on it", or "Not yet", or something like that.
In our usage, an email wishing me on my birthday offered smart replies which included "Thanks", "Thank you!", and "Happy Birthday.". The last one is just plain silly.
But in other scenarios, it worked fine. Smart Reply uses machine learning, to see how you reply to emails and gives responses based on it. So the more you use it, the better it will be.
If you have Gmail on your Android or iOS device, you should already have the smart reply feature available, as it began rolling out over the weekend.
via Google