Originally Posted by sgtcasey
Additionally, the T-Mobile network will not send an MMS to a device until the device has sent one out. This is because until an MMS leaves a device, the network does not know it can receive one. So try sending yourself an MMS.
I went through this only a few days ago. I couldn't receive photos, but I could send them out. I tried to send myself a photo, and it wouldn't work.
I called T-Mobile's BB tec support (they're excellent, by the way) and the tech told me that (as the poster above stated) you need to activate MMS on your device. He also said that trying to activate it yourself sometimes won't work, and he offered to activate it for me. Took about two minutes, and it's been working ever since.
If you're on the T-Mo network, give them a call.