Listening to others, I believe there is a way in which the sender of an email can receive notification as to whether that email has been read. Is it possible to do this on yahoo mail, and if so, how?
Within a private network then yes. The company (or home) network manager can set it up for all. But over the Internet, you can not control what the receiver's e-mail has been set to.
@snags. The person concerned is notorious for never replying to any emails. A friend of mine who has occasion to email him has some system in place so that when he denies receipt he can say, "Yes you did, you read it at xxxxhrs on x date.