1. A handheld communication device for transmission of messages to recipient devices, the handheld communication device comprising: a display; and a processor configured, in at least one mode of message composition, to: present a unified messaging interface to a user via the display for composition of messages which can be transmitted from the handheld communication device in at least two different transmittal message types, including a Short Message Service (SMS) transmittal message type and a Multimedia Message Service (MMS) transmittal message type; and automatically select one or more transmittal message types from the at least two different transmittal message types based at least in part on whether a feature, associated with a message via said unified messaging interface, is supported by the one or more transmittal message types, wherein, to perform the automatic selection of the one or more transmittal message types, the processor is configured to: automatically select an appropriate transmittal message type, from the at least two different transmittal message types, to be used for the transmission of the message, when the message has one or more associated features which are supported by only one of the at least two different transmittal message types; and automatically select a preferred transmittal message type, from the at least two different transmittal message types, to be used for the transmission of the message, when the message has one or more associated features which are supported by two or more of the at least two different transmittal message types.