How to access to prove opened e-mail?

[marseillelangres]

About 8 years ago I watched my friend go to a link on the PC that allowed him to verify if someone opened the e-mail message sent to them by him. I am sure this can still be done today. How do I go about doing this? I know there are plenty of talented people out there that must know the answer to this question.

Thank you all

[Sean K]

I know that if your using Outlook software you can make a requirement to verify that it's read. The person at the other end will know your wanting a verification.