> Basically, the impression I'm getting is that most carriers do not want 'small fish' like us to send MMS messages on their network without approval. EXACTLY!

> Basically, the impression I'm getting is that most carriers do not want 'small fish' like us to send MMS messages on their network without approval. EXACTLY! The way we circumvented the system a few years ago (2006) was to get a plain unlimited SMS plan, and then programatically send and receive SMSs through a real phone connected to the server via USB (not sure about MMS, but it is probably similar). This is very slow (12 seconds per message), and most carriers tell you "unlimited" but there is an actual limit in the fine-print. I would recommend this solution only so you can bootstrap it. If you really take off, the carrier will block you immediately, so a business model that can sustain the MMS costs is a must (as swombat pointed out). Feel free to email me if you need more info on this SMS hack.