Unlocked Sprint iPhone 4s used on T-Mobile MMS not working?

I have a Sprint iPhone 4s unlocked and I am using it on T-Mobile, my iMessage works fine from iPhone to iPhone;iPod, iPad, picture messaging from iPhone to iPhone works fine as well and SMS to and from androids works fine as well, however I cannot send any MMS to androids. Now I've been reading and asking what the issue could be some people say that MMS is not yet available on Sprint or Verison unlocked 4s, but they also say that text messaging to androids isn't available also but I can send SMS to androids back and fourth fine so I'm sure (maybe) that there might be a fix to MMS to androids also… Ive also read that I have to jailbreak my 4s to be able to send MMS but I can send MMS just not to androids, and I also read that there is no jailbreak for iOS 5.1? Is this info correct I'm not too savey with iPhones I've had androids since they came out and this is my first iPhone, so if someone could help and give me the correct info that'd be great. Thanks to all who respond.

Bring it to a phone shop and let them configure for you.iPhones are the WORST phones for putting on the wrong network, ESPECIALLY Verizon/Sprint ones since they were built to be on CDMA networks not GSM/HSPA.