Bookings Page not sending confirmation emails to customers

Hello,

I am the main technician for my company's service desk. We have a Bookings page, but any time anyone books a time slot, they receive a message indicating that they will receive a confirmation email, but no email comes to them. In the settings, it shows the checkbox to send a confirmation email is checked.

I have also looked in Exchange Admin and run a message trace and cannot find any confirmation email sent to myself or other testers.

In Bookings, I have unchecked the confirmation email checkbox, saved, checked, saved, and tested - same result. Additionally, this Bookings page is only for internal users, and all of them are 'customers' with their full organization email address. 

In researching, I found that there was mention of the Bookings needing to have an Exchange account as a shared mailbox, which I do not believe we have - when I search the email that confirms for me that someone has booked with me, it is a long string of seemingly random letters and numbers with an internal domain address. I have also tried searching in Exchange Admin for 'IT' 'Service Desk' 'Service', and 'Desk', none of which have any results under Mailboxes (which would include shared mailboxes).

Any advice/suggestions would be greatly appreciated.

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