Subject: Your invoice for . '
Dear <First>,
 
Please see pay your invoice using the following link for <JobTitle> we recently delivered to you.
https://www.paypal.com/invoice/payerView/details/<ExternalInvoiceID>
 
Thank you for your business. We enjoy serving you.
 
Sincerely,
 
<CSR>
Success Press
Phone (555) 123-4567
www.successpress.com