I was having issues sending any mms messages to my friends on other carriers. I called tmo to figure it out and they had no idea as well. The resize for the pics on mms wasnt working either. I finally resolved the issue playing around with the app snap photo. In this app you can chose the size of pic to take and if you have it set to medium it takes the right size photo and all can receive the mms. This takes the step out of cropping the photo with the stock camera app and makes for easier use. Dont know if anyone else had this issue but i thought i would post it in case. I saw numerous instances on other sites about this.