I'm having this annoying problem, and usually this is the place to look for a solution. Hope that goes for this time as well!
I recently switched service provider on my Pre 3, and therefore changed my APN settings for both internet and MMS. They are now exactly as my new provider states they should be. I'm able to surfe the web on 3G with no problem, but when I try sending an MMS, the 3G icon disappears from the top bar, and the MMS fails to send. Then shortly after, the 3G icon is back again. I'm not able to send MMS on Wi-Fi either. I can't receive MMS either.
Anybody have a clue what might be wrong?
Hope somebody can help! Thanks!