Search and Discovery in Personal Email Collections

Email has been an essential communication medium for many years. As a result, the information accumulated in our mailboxes has become valuable for all of our personal and professional activities. For years, researchers have been developing interfaces, models and algorithms to facilitate search, discovery and organization of email data. In this survey, we attempt to bring together these diverse research directions, and provide both a historical background, as well as a comprehensive overview of the recent advances in the field. In particular, we lay out all the components needed in the design of a privacy-centric email search engine, including search interface, indexing, document and query understanding, retrieval, ranking and evaluation. We also go beyond search, presenting recent work on intelligent task assistance in email. Finally, we discuss some emerging trends and future directions in email search and discovery research.