You can't use every function of the phone via PC cause you can only use the function where SE provides an API.[/list]
MPE does the sync with the phone via AT-Commands, there is no API to access MMS by AT-Commands.
It would (maybe) be possible by using Sync-ML but this is very complicated and very different to AT-Commands. FJ is working on this, but he can't say when it's finished or even if it works properly to read / write MMS.
I think that's it...
Technically enough?