Mail box transfer bug

So, i was planing to make a server transfer for my main character that is on a low population server (Sul’thraze) to a better populated server (Sulfuras), both are PVP servers. I cleaned my mail box, and had no auctions going, quited from my guild, and was ready to transfer, but then when i tried to do so, an error message says that i still have mails on the mail box. I waited 2 hours with the box empty, and even then it says that i can’t transfer. I tested transfering my alts and i could do it with no problem, just my main character is “bugged” it seems.