How can I fix my iPhone MMS send failed error on AT&T?
You are getting the notorious exclamation point when you try to send an MMS on your iPhone 3G or 3GS. There are a few steps you can try to fix the problem before you contact Apple or AT&T and they give you the same advice.
First check your AT&T Wireless account and make sure you have an active iPhone text plan. You can check this online and you should see a 200, 1500 or unlimited messaging plan on your account.