A method of multimedia communication in a mobile communications network is provided. The method comprises allocating data in a message to be transmitted via a multimedia messaging service (MMS) protocol to a sequence of protocol data units (PDU), wherein each PDU in the sequence is associated with a sequence number identifying the position of the PDU in said sequence; transmitting a first PDU in said sequence; transmitting a subsequent PDU in the sequence according to the PDU's sequence number, in response to an acknowledgment received confirming receipt of a previously transmitted PDU; retransmitting a PDU if a respective acknowledgement is not received for the PDU.