How do I customize the Event Waitlist Invitation?
When you turn on Event Level Waitlisting, rsvpBOOK creates an email template for your invitation to your registrants on the waitlist.
You can edit that message.
rsvpBOOK has 2 versions of the Admin Dashboard. Which one do you have?
Click the Email Wizard button on the Admin Dashboard.
Please see this article for help with editing this email template. How do I create an email message?