You can add a custom message and change the subject of the email receipt sent to your customers once they’ve completed a purchase.

Visit your “Settings” page, click on the “Advanced Settings” tab and then scroll down, you’ll see the following:

Fill in the “Email” and “Subject” fields in the “Email Receipt” section and then finally click the “Save Settings” button to save the changes.

Now once your customers have completed a purchase, they should see an email similar to the following: