Suggestion regarding private messages

Sounds like a simple addition, but I don't code, so I'm not sure. The addition of being able to see if somebody had opened your message you sent them. A simple <Seen on ××:yy> to the bottom of your last sent message.

I disagree, such a thing will never be added. People have a right to ignore someone, and that ignoring right comes with the right for the person not to even know if their message has been opened.