Distributed Large-scale E-mail System

Electronic mail is the most important application of Internet, the Email service deeply affects network activities such as business , education, research and so on. As fast spreading of Internet, the traditional single-machine based Email system can hardly satisfy the increasing demand of the implementation nowadays. The traditional Email system uses single server to provide both SMTP and POPS services. Resource of single machine is not enough for the increasing number of users. And also it is lack of redundance, if one spot fault occurs, the whole Email system will down. On the other hand, the traditional Email system can not provide the same environment for shift users, if users use different machines for each time, the environment can not be restored for them .The standard of Internet Email is also developing and getting more and more maturity, Simple Authentication and Security Layer, Application Configuration Access Protocol will add many new features for the next generation email system. During the process of implementing email system, we should concern about user database, message storage, server softwares, and balance strategy .The new generation of Email system will implement these standardsand technologies so as to satisfy application demand. This paper discusses the method and realization of constructing the scalable Email system with LDAP, load balance, servers cluster, ESMTP technologies.