Totally valid point. Mobile carriers are very difficult to deal with, and almost universally have a policy of shutting off access first, and then it is your duty to try and figure out why it happened so you can navigate their bureaucracy in hopes of getting things restored.

I suggested email->sms for raju's question because he was looking for a solution for his "small app" that only "potentially" needed sms capabilities, so I assumed a low-volume transaction limit, for which email->sms is a cheap and easy solution.