1. A method comprising: at a computing device having one or more processors and memory storing one or more programs for execution by the one or more processors: causing an indication of an electronic message to be displayed to a receiving user within a cluster graphic corresponding to a first message cluster in a plurality of message clusters, wherein the first message cluster includes a plurality of electronic messages, and wherein the plurality of message clusters is in a folder; detecting that the receiving user has read at least a portion of the electronic message in addition to the indication of the electronic message; polling for an affirmative action by the receiving user indicating that the electronic message is to be maintained in the folder; absent detection of the affirmative action indicating that the electronic message is to be maintained in the folder, removing the indication of the electronic message from the first message cluster; and in response to detection of the affirmative action indicating that the electronic message is to be maintained in the folder, maintaining the indication of the electronic message in the first message cluster.