There is a site option that controls this behavior and it is called CAL_SEND_CONTACT_INFO_UPDATE_AUTORESPONDER. Follow the steps below to adjust this Site Option:
  1. Go to Setup > select Site Options
  2. Click Go next to the Drop down menu with All selected
  3. Use the browser search feature (Ctrl + F) and search for CAL_SEND_CONTACT_INFO_UPDATE_AUTORESPONDER
    • If you are not able to see this option, then you will need to speak to a colleague that has Site Administrator access.
  4. Change this value to False and click Save
This will only disable the autoresponder from sending to address changes made by a constituent who is not logged in. If the constituent was logged in when they registered for the Event, then they will still receive it. There is not a way to prevent the AR from being sent if they were logged in.