29. A computer readable storage medium storing one or more programs for execution by one or more processors of a computer system, the computer readable storage medium being non-transitory, the one or more programs in the computer readable storage medium comprising: instructions for receiving a plurality of messages directed to a user, each message having a unique message identifier; instructions for associating each of the plurality of messages with a respective conversation, each conversation having a respective conversation identifier, wherein each conversation comprises a set of one or more messages sharing a common set of characteristics that meet first predefined criteria and the respective conversation identifier is distinct from a subject reference of the one or more messages in the respective conversation; instructions for associating with each conversation a set of senders of messages included in the conversation; and instructions for displaying a list of conversations in an order determined in accordance with second predefined criteria, each conversation being represented as a single item in the list, wherein a plurality of conversations in the list of conversations each include a plurality of messages that share a common set of characteristics that meet the first predefined criteria; wherein the list of conversations comprises a set of rows, each row corresponding to one of the listed conversations and including at least a sender list, a conversation topic and a date/time value, wherein the sender list of a row in the list of conversations includes identifiers of one or more senders of at least one message in the corresponding conversation, including identifiers of a plurality of the senders in the set of senders, but less than all of the senders in the set of senders, when the set of senders exceeds a predefined limit.
35. The computer readable storage medium of claim 29 , wherein every conversation in the list of conversations includes at least one message marked with a particular label; the date/time value in each row of the set of rows comprises a date/time value associated with a most recent message of the conversation that is marked with the particular label; the conversations in the list of conversations are monotonically ordered according to their date/time values.