This is just a warning to players that if you receive a mail from the "Argent Dawn" with a gift-wrapped present in it, which is also sent CoD, do not accept it - this is a scam going across many servers to steal gold from players.
Tseric noted in this thread that it will soon be impossible to do this: Coming soon in a patch near you, we will be disabling the ability to send wrapped packages by C.O.D., which should stem this particular trend we've been seeing lately.
Flagging for awareness. Notice the poor spelling and grammar. Take particular notice of the item attached. Anything that is wrapped and sent through the mail sends up red flags for me, I don't know about you folks.
Be sure to notify a GM should you receive such an item.
While this issue is being fixed in 2.0.7, it's important to be careful until then on what CoD items you accept. In this case, please do not accept the CoD, and do report the player sending it. Hopefully Blizzard can track down and ban these scumbags for trying to take advantage of the playerbase on such a large scale.