1. A database system for sharing a message of a conversation in a feed of a social networking system having a plurality of users, each user having a distinct user designator stored in a database of the database system, the database system configurable to cause: processing first user input selecting one of a plurality of messages of a conversation in a feed of a social networking system, the feed accessible via the social networking system and configured to be displayed in a user interface on a display device, the user interface configured to permit a user to submit a reply to a message of the conversation, the reply capable of being incorporated as a message of the conversation viewable by at least a portion of the users of the social networking system; processing second user input received via the user interface, the second user input identifying an email address of an existing or possible participant in the conversation, the email address being other than a user designator of the social networking system and being external to the social networking system; generating an email in a format other than a feed format of the feed of the social networking system, the email including the selected message; sending the generated email to the email address, the email capable of being delivered, at least partly, through a communications network apart from the feed of the social networking system; processing a response email from the email address; determining that the response email is permitted to be included in the feed; and responsive to determining that the response email is permitted to be included in the feed, displaying, in the user interface on the display device, at least a portion of the response email in the feed, the portion of the response email being displayed in association with an identification of the participant.