What is the best way to programmatically send an SMS text message?
Are there any free Web Service based SMS gateways?
I know that if I happen to know the user's carrier (Sprint, AT&T, etc), I can send an SMS by emailing an address based on phone number + carrier. I would like a good solution that does not require me to know the carrier. Barring that, is there an easy way to lookup carrier given a cell phone number?
I understand that there are some services independent of the major mobile carriers that offer a per-message fee-based service, with API. What I would like to know is how such organizations tap into the SMS networks. Do they have contracts with mobile carriers to resell their services?
Answer
They have a REST interface to send SMS's and even to establish phone calls or receive phone calls.
You even get 30$ credits to try it out.
Def. the cheapest solution you will find.