1. A method, performed by a client device having one or more processors and memory storing one or more programs for execution by the one or more processors, comprising: at the client device: in response to a user input requesting display of a user-selected email thread, displaying message content from one or more email messages in the user-selected email thread; displaying, concurrently with the message content from the one or more email messages, a plurality of respective social network objects distinct from the message content, wherein the plurality of social network objects are displayed in a display region reserved for non-email content, each displayed social network object corresponding to a single post by a respective participant in the email thread and having a content portion from only the single respective post to a social network by the respective participant in the email thread and one or more selectable portions distinct from the content portion of the social network object, the plurality of displayed social network objects including social network objects corresponding to posts by a plurality of participants in the email thread; and in response to selection of a first selectable portion of a respective social network object of the one or more displayed social network objects, displaying a respective social network page of the respective participant who authored the respective post corresponding to the respective social network object; wherein the client device is associated with a first user, who is a first participant of the plurality of participants in the user-selected email thread, and the number of said social network objects having content corresponding to posts by the plurality of participants in the email thread and displayed concurrently with the message content from the one or more email messages is determined in accordance with a number of participants, other than the first user, in the user-selected email thread.