Management of messages included in a message thread displayed by a handheld device

The present invention determines which messages to display in message threads to a user. An electronic communication device receives and stores numerous SMS messages transported through an SMS network, but the SMS messages are sent without explicit linking information such as a previous message or subject line. A threading module applies threading rules to determine which messages to correlate into an SMS message thread through implicit link information. The threading rules thread outgoing messages sent in response to an incoming message from a user, or incoming messages where a previous outgoing message was sent to the user. An SMS application displays threads in a user interface and indicates messages threads with an icon in one view, and displays an expanded message thread in another view.