10. The system of claim 9 , wherein each obtained conversation is associated with a unique numeric conversation identifier.
9. A conversation-based message system, comprising: one or more conversation servers, the one or more conversation servers comprising: memory; one or more processors; and one or more programs stored in the memory and configured to be executed by the one or more processors, the one or more programs comprising instructions to: receive a search query; in response to receiving the search query: obtain, from a message repository, conversations relevant to the search query; create a list of conversations representing at least a subset of the obtained conversations, wherein each conversation in the list of conversations is represented as a single item, and at least one of the conversations in the list of conversations comprises two or more electronic messages from distinct senders; identify, for each conversation in the list of conversations, a portion of conversation content relevant to the search query; and produce, for concurrent display at a client, a search result including at least the list of conversations, and the identified portion of conversation content for each conversation in the list of conversations.