I'm on a pre-paid T-Mobil plan and today I got a new phone (the one mentioned above). I've always been able to txt, but once I switched over to this new one it says that I'm unable to send txt messages.

I can call other people, and I can receive txts, I just can't seem to send them. So I was wondering if there was something I maybe needed to activate or to do. Any input would be appreciated, thanks!