use FAQ on blackberry manual for your model you will find on blackberry website. I used that once and I remember there was a specific problem about when MMS can't be used. MMS use GPRS and if you don't have BB data plan you may not be able to use MMS. See in the right upper corner whether you have GSM or gprs/edge. You need at least gprs with small letters to use MMS and capital letters (GPRS/EDGE) to use email.