In an embodiment, a computer-implemented data processing method comprises, in a collaborative electronic information management system that is hosted using a collaboration computer, establishing operation of a plurality of event listener units, wherein each of the event listener units is configured to communicate with or listen for a plurality of application events that have been generated by a particular corresponding external application; determining that one or more of the application events relate to a particular content item from among a plurality of content items that are managed in the system; generating and causing displaying, as a part of a graphical user interface of the system for a user account associated with a user computer, a set of notifications comprising one or more first notifications generated from the system and one or more second notifications that are based upon the application events, in association with data identifying the particular content item.