Server Transfer Mail Problem

I've been trying to transfer my mage (Shatterlol - Mal'ganis) for a few hours now with no luck.

Keep getting this message:

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 have no mail in my inbox and would appreciate help on this issue.

Thanks :)