Many email clients such as outlook has a feature that allows you to request a receipt when your email is read by the recipient(s).
It can be achieved in asp.net generated emails using additional header called Disposition-Notification-To
Here is simple code
MailMessage email = new MailMessage(fromAddress, toAddress);
email.Headers.Add("Disposition-Notification-To", receiptToEmailAddress); //Use email address on which you want receive the receipt
Kiran Beladiya is the co-founder of The One Technologies. He plays a key role in managing the entire project lifecycle, from discussing ideas with clients to overseeing successful releases. Deeply passionate about technology and creativity, he is also an avid writer who continues to nurture and refine his writing skills despite a demanding schedule. Through his work and writing, Kiran Beladiya shares practical insights drawn from real-world experience.
