I have been having this issue for about a week now. When I try to send a text to a certain contact, it will attempt to send then I get the sending failed message. If I send the text to that person leaving off the 1 and the area code that automatically get attached my texts send fine. I have tried removing the battery and restarting multiple time even had the person try it with their phone and still getting the same issue. I get the same result no matter which text program I try stock, GoSMSPro (the one I use all the time, or hancent (tried it didn't care for it). The person I am texting is not using a smartphone but I have not sure which one it they have i think it is a samsung touchscreen phone but it does not run android i know that. Additionally I can respond through the push notifications and have no issues but when I try to reply through the actual text apps, it fails unless I drop the 1 and area code. If anybody has any ideas about how to fix this issue please let me know.