This is usually an easy fix for sprint users depending on what rom youre using. U can install the cab posted above which comes with a version of Arcsoft MMS Composer thats known to work well on Sprint and comes preset with sprint mms settings and that should work and be the easiest way to get mms functioning. If it doesnt work u can search for Sprint Arcsoft cabs or Sprint arcsoft settings,if u choose to setup arcsoft settings manually. U could also try a Sprint Provisioning cab and that should setup your MMS settings for u on the roms cooked in Arcsoft MMS Composer,if the rom has one cooked in,most do, but it depends on the rom. The only way i can get my MMS to function is to remove the HTC Messaging Client,if it has it, and use only the Windows Msging Client with only this particular Arcsoft MMS Composer Version 5.2.6.34,from the HTC Imagio. I really dont know why but that version of Arcsoft is the only version of Arcsoft ive been able to get MMS to function correctly and stable, but im on Cricket. Ive heard that as long as u use the Windows Msging client with a Sprint provisioning cab MMS should function correctly with most Arcsoft versions on most custom roms. My only complaint with the only version of arcsoft that works for me is that it has a max send limit of 1024kb, and i know that there are some versions or a way to increase the send limit to 5mb,ive even heard of a 10mb send limit,but never seen it and i doubt it.If all else fails try setting up whatever version of arcsoft that comes cooked into the rom with your sprint settings manually.Or u could do a search for, Sprint Arcsoft setup cab, or Sprint Arcsoft MMS Composer cab, and im sure u will come up with a bunch of results. Id start with the most recent cabs and then test and work my way down til u find one that works.Im sure u will find one. I think the Arcsoft Posted above is pretty recent and works well. Good luck.