Currently working on a j2me project for sending MMS to a phone. Currently using a modified version of Nokia MMS Library. My mms is composing well, also have tested it on the sample app provided by Nokia which responds.
When i debug the same using a live MMSC from Cingular i receive a response as Server HeaderList 1: .1 400 Bad Request. This shows that am able to connect to the server but not able to compose the data as needed(not quite sure).
My cingular setting are (Reference)
Proxy (name : port): wireless.cingular.com:80
MMSC URL: http://mmsc.cingular.com:80

Waiting for your response ASAP.