Mail glitch; transfer impossible

Ive been trying to transfer a character from 1 realm to another... and it says I cant because I

Q u o t e:
The character you are trying to transfer has mail in his or her mailbox, or inbound mail that hasn't arrived yet (possibly from a quest). Please wait until all inbound mail has arrived and make sure your mailbox is empty before trying again.

I got this error 4 hours ago. No mail has arrived... ive double checked everything, turned off all my addons, tried everything. Glitch?