Here's an idea Peg came up with after playing WOW for the other day for the first time. I posted this ont he Blizzard suggestions forum. Lets see if they really do it.
My girlfriend just started playing WOW and she was very dissapointed when she received an ingame mail from a Troll and the mail was written in.... ENGLISH!
She wants MONSTER MAIL, where we Horde can send a message that is undecipherable to the other horde races, and then sign the back of the letter with a giant hoof-print (or 2-finger toe print, rotten foot, etc.)
When you receive a MONSTER MAIL, your character will pick it up out of the mail box, look at it and be all confused, because MONSTER MAIL is jibberish! Then your character will flip the MONSTER MAIL over and see the GIANT HOOF-PRINT on the back and look very very confused.
Maybe there can be an animated lightning bolt of confusin over your character's head.
I told her that the game is patched every week, so maybe if you guys get working on this today it can be in the Tuesday patch!