Today, I tried again after learning the AT&T Carrier File 5.6 update was supposed to fix this very problem, but still no go.  Boo hiss.   Google searches revealed lots of people having this problem and several possible solutions ranging from rebooting the phone, resetting the Network settings in the phone, swapping out the SIM card for a new one, or even doing a complete backup, reset, and restore of all data on the phone.  I tried the easy ones, rebooting, and resetting network settings, but still no luck.

I also found several people who had issues with their settings in various backend AT&T databases that prevented MMS on iPhone from working.  One person, who already had an AT&T account, got an iPhone and the AT&T rep put him on the ‘Messaging 200′ plan instead of the ‘iPhone Messagin 200′ plan. His MMS service didn’t work until he got switched to the ‘iPhone Messaging 200′ plan.  AHA!  I logged into my AT&T wireless account, and sure enough, I had the ‘Messaging 200′ plan.  I switched over to the iPhone messaging 200 plan, waited a couple minutes, and then tried sending an MMS text message. It went through just fine.

My question is: Why did the  AT&T rep selling an existing cusomter, me, a new iPhone 3GS set me up with the ‘Messaging 200′ plan instead of the ‘iPhone Messaging 200′ plan? Seems like a FAIL way to do things.