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.