I cant send sms messages or MMS on my new samsung wave. It just saves automatically to my outbox (as opposed to my sentbox) and the other person does not receive a message from me.

It comes up with a message saying service unavailable, but I dont know why? Ive made my messages smaller from 600 mb to 100mb incase the other persons phone is of a lower capacity than mine but its not made a difference...

Anyone have any ideas about things to try?