A mobile communications device receives and handles an encoded message. State data about the encoded message is generated based upon a first access of the encoded message. The device stores the generated message state data in a cache of the mobile communications device; generates a message indicator based upon the message state data stored in the cache of the mobile device; and processes the encoded message on a background thread running on the mobile device. The process determines that a message state change has occurred since the message was last opened and provides an updated message indicator to a user of the mobile device that reflects the message state change.