BlackBerry Pin and MMS doesn't work!?

I have a blackberry stlye and I usally take a bunch of pictures and send them to friends. But suddenly it stopped working. Everytime I try to send a MMS it has this little red time box and after a. Few seconds it turns into an X. I need help please and thank you! And I've tried the enterprise activation and it won't accept my email address! -_______- help please