I mail items to people every once in a while but I'm never sure if the person opens or receives it. My suggestion is to have a message that says "[player] has received [item(s) you sent]" to be sent to you when a player opens your mail. If you happen to be logged off at the time the player opens the mail, the message should be shown when you log on.
Correct me if I'm wrong, but doesn't this already happen? I could be mistaken for something else, however.
He is saying that the sender of the mail Would receive a message once the..receiver of the mail does /mail get. I like this idea!
Oh I understand how you could make that mistake. There's a message that says mail was sent to you. My suggestion is a message to the player that sent the mail. The message would be sent to notify the sender that the player who was sent the mail, has received it.