Hello, @scortezlpc.
We aren't able to check whether the receipt was sent to a client or not. As a workaround, you can CC yourself so you'll receive an email as well when sending the receipts to your customer. You can do it by clicking on the Cc/Bcc link, then add your email address beside the Cc or Bcc field.
In case you need additional reference while working with QuickBooks Self-Employed in the future, feel free to open our help articles and get the topic/s you need.
If there's anything else I can do for you, please don't hesitate to leave a comment below. I'll get back here as soon as I can to help you again. Keep safe!