Unable to faction transfer due to mail

Hello! I've been trying to faction xfer this char so I can play with some buddies, but I keep getting the "character cannot change factions while there is mail in their mailbox or en route to their mailbox" error. I've stayed away from the AH and deleted everything out of my mailbox and waited, but still no dice. :(

Any suggestions on what I should do, or am I just being impatient? =x