When I flashed my HTC Desire HD to CyanogenMod 7, I lost the feature to both send and recive MMS. After some looking around, poking here and there, I finally solved it rather easy. The issue was that the URL for the MMS settings in the Access point names (APN).
- Go to Settings -> Wireless & Networks -> Mobile Networks -> Access Point Names.
- See if the MMSC, MMS proxy and MMS port is right by comparing them with a list of settings, based on your operator.
I have only tried this for a Swedish operator, and I haven't a list with the rest of the world, so just google for 'APN list android'.
- Change it if somethings wrong and then you're good do go.
MMS proxy: 172.016.053.011
MMS port: 8799