I am thinking about writing an app centered around SMS messages. I'm leaning towards sending out the text messages via the provided carrier email gateways (since it's free). I mainly concentrated on US based cell customers.
Will the carrier bock my domain if I start sending 5,000 emails to subscribed cell customers on their network?
Do you have any real-world experience with sending large number of text messages via the various carrier email gateways? What are some of the gotchas?