php - How to get notification that email has been open

Does anyone of you know off by hand what mail headers to add in order to get a read receipt and delivery report? This now being when you use the normal PHP mail function. No fancy add-on script / class like phpMail. answer below For the reading confirmations: You have to add the X-Confirm-Reading-To header. X-Confirm-Reading-To: <address> For delivery confirmations: You have to add the Disposition-Notification-To header.