FAQ 000178 – How to change the sender and reply E-mail address in Microsoft Bookings
PROBLEM You want to change the sender e-mail address (From:) as well as the reply address (Reply-To:) in Microsoft Bookings. DESCRIPTION When you create a Booking page in Microsoft bookings a scheduling mailbox is created. Those mailboxes are not shown in Exchange admin console by default and you need to use Exchange Online PowerShell