1. A system for providing selective notifications in an enterprise social networking system, the system comprising: a database system implemented using a server system comprising one or more hardware processors, the database system configurable to cause: processing a first feed item shared in a feed of the enterprise social networking system by a first user of the enterprise social networking system, the first feed item comprising a notification identifying a file uploaded to the enterprise social networking system, the first feed item capable of being stored in a database of the database system and capable of being displayed as part of the feed in a user interface on a display device; providing, to a computing device of a second user of the enterprise social networking system, notification options in association with the first feed item; processing a selection of the notification options, the selected notification options defining a plurality of conditions for identifying feed items in an e-mail to be automatically provided to the computing device of the second user of the enterprise social networking system in response to the conditions being met, the conditions comprising at least: a timeout condition defined by a time interval during which the notification options are active, the notification options being configured to be automatically de-activated after the time interval has elapsed, the time interval being customizable by the second user, a designated business relationship between users in an organizational hierarchy of the enterprise, a reference to a file uploaded to the enterprise social networking system, and a minimum number of indications of personal preference submitted by users of the enterprise social networking system having the designated business relationship with the second user; storing the notification options in a database of the database system; determining, based on the stored notification options, that the time interval has not elapsed; determining, based on the stored notification options, that the first user and the second user have the designated business relationship in the organizational hierarchy of the enterprise; determining, based on the stored notification options, that the first feed item comprises or identifies the file uploaded to the enterprise social networking system; determining, based on the stored notification options, that the minimum number of indications of personal preference regarding the first feed item have been submitted by users of the enterprise social networking system having the designated business relationship with the second user; automatically generating, responsive to the determinations, a first e-mail identifying the first feed item; and automatically providing the first e-mail over a data network to the computing device of the second user.