A server having one or more processors and memory stores a conversation including a plurality of messages, where the conversation is associated with a first label and a respective message of the plurality of messages is associated with a second label. The server receives a predefined request from a remotely located client system and responds to the predefined request by producing and sending to the client system a list of conversations. When the predefined request corresponds to a request for conversations associated with the first label, the server sends, to the client system, a first list of conversations associated with the first label. When the predefined request corresponds to a request for conversations including messages associated with the second label, the server sends, to the client system, a second list of conversations that include at least one message to which the second label has been assigned.