When someone uses YCBM internally with our same domain, they do not receive any notifications that the appointment has been booked. Our team receives notification that it has been booked and the appointment is added to the calendar. We’ve done several tests and they are blocked each time but when we use a generic email it works fine.
It sounds like there is a DMARC policy on your domain preventing us from sending emails from that email address. Please use the Get Help button on your dashboard to get in touch with our support team so they can confirm that for you and explore your options.