As more people use e-mail at home or on the job, more people have come to experience the pain of e-mail that Denning first wrote about 20 years ago . In this paper, we present data from a field study in our own company to add to the existing body of research about how people use e-mail. We then use these data and prior literature to outline a framework of the five main activities that we believe people use e-mail for. In particular, we focus on two activities that we believe have been under-studied: attending to the flow of messages they arrive, and doing “triage” on a body of new messages. In addition, we outline potential design directions for improving the e-mail experience, with a focus on e-mail clients that group messages and their replies together into threads. We present a prototype of such an interface as well as results from a lab study of the prototype.