Models of mail server workloads

Electronic mail has become an integral part of our daily lives. With this trend, mail servers have to provide a fast, highly available, reliable and secure service. Hence, workload characterization and performance evaluation of mail servers are to be addressed as primary issues. This paper deals with a detailed characterization of mail server workloads. Our study is based on the analysis of a large set of measurements collected on various mail servers. We analyze SMTP and POP3 requests and we obtain models able to capture and reproduce their behavior and most relevant characteristics. These models represent the basis for the definition of the workload of SPECmail2001, a benchmark currently under development within SPEC to assess the ability of a system to act as a mail server.