i Worked with gsm for a bit and most ports/gateways dont have any issue sendins sms, the only problem is the charge system. how much you pay for it etc. And also depends on the area targeted and the type of ports, because most telecom companies have anty spam/fraud systems that detect really fast unstable systems.I'm in Vietnam, I want to send SMS to target in the U.S., I have my own GSM port, can this GSM port send SMS to the target in the U.S.?