This isn't really an exploit of any sorts, more of just abusing the stupidity of the Alliance. This probably wouldn't work too well after this Christmas patch, but I'm sure you could figure out another circumstance when to apply it ::
With all the Christmas quests dealing with Smokeywood Pastures, and lots of the the quest rewards being delivered through the mail (Snowman Outfit), I created a few characters named Smokeywood, Pastures, etc. I then proceded to just /who Ironforge, /who Stormwind City etc. I sent tons of C.O.D. mails out entitled "Your Christmas Present!" "Your New Years Present" "Your Channukah Present" with a C.O.D. of 5g. They would all open it to find 1 piece of Coal. I made over 450 gold doing this, all thanks to the stupidity of Alliance carebears on my server.
With all the Christmas quests dealing with Smokeywood Pastures, and lots of the the quest rewards being delivered through the mail (Snowman Outfit), I created a few characters named Smokeywood, Pastures, etc. I then proceded to just /who Ironforge, /who Stormwind City etc. I sent tons of C.O.D. mails out entitled "Your Christmas Present!" "Your New Years Present" "Your Channukah Present" with a C.O.D. of 5g. They would all open it to find 1 piece of Coal. I made over 450 gold doing this, all thanks to the stupidity of Alliance carebears on my server.