Automatically summarizing electronic communication conversation threads is provided. Electronic mails, text messages, tasks, questions and answers, meeting requests, calendar items, and the like are processed via a combination of natural language processing and heuristics. For a given conversation thread, for example, an electronic mail thread associated with a given task, a text summary of the thread is generated to highlight the most important text in the thread. The text summary is presented to a user in a visual user interface to allow the user to quickly understand the significance or relevance of the thread.