To recap how to send the receipt:
1. Ring up a sale
2. Press the [Email Receipt] button
3. Enter a new customer with an email address or lookup and existing customer
4. Press [OK] from the Customer Lookup screen with the customer's name and email displayed on the link above the buttons.
5. The register screen will be displayed. About 10 seconds or so later, a message will pop up saying "Email sent successfully"