Whenever the landlord/vendor is the one doing the viewing, you have to assign them organiser right at the top. In this scenario the agent is the one doing the viewing (the organiser), and the instant confirmation you send to the "attendee" will go to the agent. The attendee for a viewing can be selected using the dropdown list.

If the landlord is the one doing the viewing you will need to be selected them as the organiser. This will remove the options to send an instant confirmation to the landlord as they're now the organiser (the person attending the viewing). So whenever you want to send an instant confirmation or setting up a reminder alert for the landlord, select "attendee".
