AFAIK fMMS use just data connection (every mms phone do it, although hiding it from user) via 2.5G. The point is, that it connect to "different" provider, aka mobile access point (or how it's called?). The point is that using predefinied access point for mms, You're not charged for data connection (although physically it *is* data connection).

That's why I suggested, that it may be worth checking eventlogger for data connections - if it is possible to determine which ("connection settings"), ap was used.

Sorry if You already checked for that - I wanted to be sure that my suggestion wasn't understand wrong way BTw, maybe it's possible to ask fMMS developer to add some backend, that You can use in this hack? Is it possible?