Why does my phone keep saying that outbox is full ?

Hi my phones every time a message comes in i cant see it kuz it says message box full...When really theres no messages at all...Is there anything i can do ? ?|||Maybe because this whole time you haven't been sending any messages at all. When messages dont send they go to your outbox.|||You need to contact your phone service representative and tell them what the problem is, they will then tell you how to resolve it.