1. A computer-implemented method performed at a server system having one or more processors and memory, the method comprising: responding to a single search query, including: searching a message repository to identify a plurality of conversations relevant to the search query, wherein each of the plurality of the identified conversations includes one or more messages sharing a common set of characteristics that meet predefined criteria, and wherein each of the plurality of the identified conversations includes a respective conversation identifier, and sending a list of conversations representing at least a subset of the identified conversations, wherein at least one of the conversations in the list includes a plurality of email messages; providing content of a selected conversation from the list of conversations including text formatted so as to differentiate between first text of the selected conversation and second text of the selected conversation; wherein the second text includes text matching the search query and the first text does not include text matching the search query; and providing formatting information for the first text in a first format and providing formatting information for the second text in a second format; wherein the first format differs from the second format in a visually distinctive manner.