well, with bell mobility it works different, might work the same with sprint. dial *94(1-9)
the (1-9) means the number of rings it take before it gets forwarded to the message center. ex: dial *945 and it will take 5 rings before it gets forwarded
gsm doesnt work the same as cdma. the information is in his QHLR. try it, tell me if it works for sprint also
