Heres a quick tip. If you need to include a request for read receipt like Microsoft Outlook while sending mails through Asp.net, just add the Disposition-Notification-To Header to the MailMessage.

The MailMessage class does not have a corresponding attribute and thus it has to be set through the Header.

MailMessage mm = new MailMessage(fromAddress, toAddress);
mm.Subject = subject;
mm.Headers.Add("Disposition-Notification-To", sendReadReceiptToAddress);


Please keep in mind that this is only a request, and can be rejected/ignored by the Mail Client/User configuration.