Exclamation [Q] Cannot send MMS with APN settings for Samsung Galaxy Note II

I am getting so extremely frustrated!!! GRR
I have a T Mobile Note II. T Mobile gave me the unlock code so I can use my phone with AT&T.
I am unable to get service with the default AT&T APN settings.
I searched AT&T's help center and all over xda's forums for the correct settings.
I've tried several of the settings. The recurring problem with ALL of the settings is : I cannot send MMS.
I'm able to receive MMS though. SMS and data work just fine with all the settings I've tried.
And, yes, I restart my phone after every APN change I make.
Any suggestions would be helpful.