Hey there @SaraThack - great question and thanks for your post! 

There is currently no way to ensure that an invitee can only book with you once (or any specific number of times), nor is there a way to block bookings based on email address or otherwise. 

You might be interested in exploring these alternatives: 

• You could make the event secret which would ensure it does not appear on your main scheduling page. Any invitees would need to use the event-specific link to access your booking page, which would only be provided by you.
• You could also consider sharing single-use links for specific event types. With single-use links, meeting links will expire once used and invitees will not be able to book another. Your event-type URL will never be exposed, preventing any unwanted repeat bookings on your calendar.

I am sorry for any inconvenience this might cause, and do hope that you have a good day! 

Thanks, Kelsi! Is there a way to mass generate single-use links? This email would be going out to a lot of people in a mass email situation, so we can’t create a link for each person manually & send them one at a time. Appreciate the insight! 

You are so welcome! Unfortunately there is no way to mass generate single-use links, as this would result in the event type’s link being single-use, meaning only one person would be able to use it. I do wish there was a better answer I could offer you, and I apologize for the inconvenience!