A method carried out by an electronic device enabled to send and receive electronic messages over a network, including: determining if a new electronic message received by the device is part of a message thread that includes the new message and at least one prior electronic message previously received at the device; and if the new message is determined to be part of a message thread, comparing address information of the new message with address information of the at least one prior electronic message in the message thread to determine if there has been a change in addressed recipients between the new message and the at least one prior electronic message, and if so, providing a notification to a user of the device of the existence of the change.