Originally Posted by 13oilerUp
...I do not have 3G where I tried it, but I was connected to wifi. SMS worked fine but MMS wouldn't go through...
MMS only works over 3G, not 1G or wifi, so MMS will not send/receive without 3G enabled.
SMS will work over 1G, so even if you have wifi on, SMS will still send/receive.
If you have both 3G and wifi connected, it will normally automatically enable the 3G connection long enough to send, then switch back to wifi. However, if another service is using the network connection over wifi at that moment, it will not close the connection and open a 3G connection till a later time.