In case your attendee opens your email on Gmail, G Suite, Outlook, Yahoo, Hotmail, MSN, your calendar will automatically appear in the email. Notably, your client can now interact with your calendar using the latest technology in email marketing, which is the Actionable Messages and AMP. 

If, however, your attendee views the email on other email clients, they will see a button with a link in the email. The link redirects them to a new web page showing your updated calendar and availability to make an appointment.