You can automatically send a payment receipt to a guest via email, by configuring this in the Merchant Management System (MMS).
Once logged in, click the 'Preferences' menu and select the 'Receipts' tab.
By setting Customer Receipt Required = 'Yes', any successful Sale transactions passed to Caterpay, where the guest has an email address configured, will be sent a receipt.
Important: Unless you configure your own email address here, the sender will be no-reply@caterbook.com - any reply from your guest to this email address will not reach you, and in fact would not be seen by our own staff either.