I have a program that sends SMS thru pop. Problem is we can not get t-mobile to work on it and not sure what needs to be changed in the code. IF you have experience in programming sites or code of this nature then send me a PM and tell me "exactly" what other programs you've worked on like it.
Since the path is phone company->SMS-to-SMTP-gateway->your POP3 server, the problem is most likely the gateway - it doesn't handle T-Mobile. You'll have to find a gateway that does.