A study of e-mail patterns

Although electronic mail is an increasingly important service, there are few empirical studies of e-mail traffic. We have observed over 2.85 million messages passing through our departmental servers over the course of seven months, and derived distributions that approximate several important e-mail parameters including message sizes, message senders and receivers and the burstiness of message deliveries. Our work is unique in that we also analyse message payloads: attachment content types, e-mail redundancy, and the use of e-mail as a sharing mechanism. These data can be used in developing e-mail workloads for mail system engineering or benchmarking. To this end, we provide an improved version of Postmark, a small-file Internet benchmark, that better approximates mail server characteristics. Copyright c © 2007 John Wiley & Sons, Ltd.