Like many email programs, Outlook can recognize emails that contain an invitation to a meeting or event, and will ask if you want to accept or decline the invitation. And, if you accept, Outlook can automatically add the event to your calendar for you.
However, Outlook 2016 adds a new option here, called Propose New Time. If you do want to attend a meeting but you decide that the suggested time doesn’t suit you, then you can send another email in reply that says ‘how about this time instead?’.
Unfortunately, the Outlook help files don’t say what will happen if 10 different people suggest 10 different times.