To download MMS settings:

1)From the Home screen, tap the applications bar.
2)Tap Settings > Wireless controls > Mobile networks > Auto Internet settings.
3)Select your operator and tap OK.
4)The info pop-up shows settings status, tap OK to return to Mobile network settings.

To check the Multimedia access point:

1)From the Home screen, tap the applications bar.
2)Tap Settings > Wireless controls > Mobile networks > Access Point Names.
3)Defined multimedia message access points is listed.
4)To add a new access point. Press the Menu key and tap New APN and enter settings.
When done, press the Menu key and tap Save.

Check the settings for MMS. Got to the Application screens icon. Then Settings > Wireless & networks > Mobile networks > Access Point Names. If no APN's, return to the Settings menu and tap Sony Ericsson > Settings download > Accept to download settings for MMS.

I can’t receive or neither sends MMS from my phone. I heard its Android problem? Please help guys!