In order to email a receipt in MPOS, a customer must verbally give their email address so it can be entered into MPOS - either upon completion of a sale or on a customer record. Not all customers are comfortable verbally giving their email address. It would be great if the out of the box Adyen integration included a prompt to the customer on the pin pad of whether or not they wanted their receipt emailed or printed. If they select email, ideally they'd be able to enter their email address on the pin pad itself and have it synced back to a new customer record if that email does not already exist in D365. Based on Adyen's documentation it seems the email collection and prompt for emailed receipt is all functionality that is available.