Rather like LinkedIn, Outlook is now suggesting quick ways to reply to email messages.
Outlook will suggest three possible replies to an email you have received. Clicking on one of the suggestions, opens the Outlook reply window, with that option already typed at the top of the message. You can then edit the message further, before you send it.
Suggestions for replies are based on machine learning that Microsoft say is conducted on your own mail server, so no information is shared outside of that. It depends on the content as to whether Outlook will suggest replies.
Outlook adapts its suggestions based on your comments. Clicking on the Feedback link brings up a window for you to provide that feedback. You can choose from various pre-selected options as to why the suggestions might not be suitable and add your own more detailed comments.
The more training you provide the more accurate the suggestions. But, if you don't like the suggested replies you can turn them off entirely by doing this:
You can also turn the suggestions off in the following way: