A high performance and low cost cluster-based e-mail system

A large-scale e-mail service provider requests a highly scalable and available e-mail system to accommodate the increasing volume of e-mail traffic as well as the increasing number of e-mail users. To reduce the system development and maintenance cost, it is requested to make the system modular using off-the-shelf components. In this paper, we propose a cluster-based e-mail system architecture to achieve the goals of high scalability and availability, and low development and maintenance cost. We adopt the internal structure of a typical Internet e-mail system for a single server, called the MTA-MDA structure, to the proposed system architecture for the low cost requirements. We have implemented four different system configurations with the MTA-MDA structure and compare their performances. Experimental results show that the proposed system architecture achieves all the design objectives.