Smart Reply

Smart Reply is a deep neural network that, for emails answerable with a quick reply, automatically suggests replies to the email. Someone can edit the chosen reply or send it off as is with a tap. The feature was launched in November 2015 and works by, first, encoding the incoming email into a list of numbers called a 'thought vector'. It homes in on the part of the email most relevant to predicting the reply. Then, based on the 'thought vector', a neural network synthesizes likely short responses to the email, such as 'We'll be there!' and 'I'll see if I can find out.'

Source: https://research.googleblog.com/2015/11/computer-respond-to-this-email.html