42. The server system of claim 33 , wherein a least one message in the plurality of messages is directed to a plurality of users including the particular user.
33. A server system, for processing messages, comprising: one or more processing units for executing programs; memory storing one or more programs be executed by the one or more processing units; the one or more programs comprising instructions for: receiving a plurality of messages directed to a user, each message having a unique message identifier; associating each of the plurality of messages with a respective conversation; associating with each conversation a sender list, the sender list identifying a set of senders of messages included in the conversation; and providing presentation information for displaying a list of conversations and their associated sender lists comprising a set of rows, wherein the presentation information is formatted such that: conversation identifying information for each conversation in the list of conversations is displayed as a single row in the set of rows; and the sender list associated with the conversation is displayed in the same single row, along with the conversation identifying information; and wherein a displayed sender list of at least one respective conversation in the list of conversations identifies two or more distinct senders of messages in the respective conversation.