Characterization of IMAPS Email Traffic

The email delivery ecosystem in modern enterprise networks is large and complex, featuring several email access protocols (e.g., POP, IMAP, HTTP, and the secure versions of each of these). In this paper, we provide a detailed characterization of IMAPS email traffic on a large campus edge network. The main highlights from our study are: (1) commercial cloud-based email services account for most of the campus email traffic; (2) all email access protocols exhibit heavy-tailed transfer size distributions; and (3) the throughputs achieved by large transfers vary widely based on protocol, transfer size, and time of day.