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.

多年来，电子邮件一直是必不可少的通信媒介。因此，我们邮箱中积累的信息对我们所有的个人和职业活动都非常有价值。多年来，研究人员一直在开发界面、模型和算法来促进电子邮件数据的搜索、发现和组织。在本次调查中，我们试图将这些不同的研究方向结合在一起，并提供历史背景以及对该领域最新进展的全面概述。特别是，我们列出了设计以隐私为中心的电子邮件搜索引擎所需的所有组件，包括搜索界面、索引、文档和查询理解、检索、排名和评估。我们还超越了搜索，展示了电子邮件中智能任务辅助的最新工作。最后，