Why won't my Iphone send MMS to nonIphone's?

I can send MMS to an Iphone but when I want to send one to a noniphone it wont send. It looks like it will come close to sending but then it just says message failed. I need help! This is really annoying!

Because it is only for iphones. Or oyher apple products such as ipad ipod etc.

If you are using the simple texting service to attach some file, recorded audio, video etc. And it gets failed to send, then contact your service carrier about activation of MMS service on your phone.
You might be using some apple service for sending stuff which dosen't support on non-apple devices.