I've spent the past few days trying to get MMS to work on the N900.
I started by trying to enable receiving so I can try to monitor DBUS and see what's going on. This failed and my operator (Elisa Finland) sent me an SMS stating that they can't send me the MMS configuration and I have to send an MMS first (According to Google translate's Finnish to English translation).
I then decided to try implementing sending.
I needed a custom MMS encoder so I can build my MMS. I also discovered that I know nothing about these things and started working on an MMS encoder/decoder.
I used a sample MMS, enjected my number and kept trying.
After long hours of working, I managed to hear my N95 vibrating and it was it :-D
This is just a proof of concept. Sending works. I need to figure out how to receive the wap push notification and how to bring up the GPRS connection in a clean way.
I'll post detailed instructions and the code I used when I get some sleep ;-)
Here's the HTTP headers sent:
User-Agent: NokiaN95_8GB/31.0.015; Series60/3.1 Profile/MIDP-2.0 Configuration/CLDC-1.1
Accept: */*, application/vnd.wap.mms-message, application/vnd.wap.sic
Accept-Charset: utf-8\r\nAccept-Language: en
Ah, and I didn't yet parse the reply I've received from elisa's server ;-)
Finally, a nice screenshot of my terminal: