Large-Scale Email Systems Design And Implementation

From the birth of email system, Email Application has become the most important Application of the Internet. With the developing of Internet, email system become more and more common and popular. The traditional email system has many flaw, it becomes more obvious when with a heavy load. Large-scale email system has features such as high Scanlability, good portability, high speed and high ability. Most important, the high scanlability makes Internet providers configure their own system and enlarge scale with situation.Large-scale email system has a concept of Application server. Large-scale email system has an architecture at least three tiers. In order to accomplish scanlability and load balance, system adopt different algorithm and choose process, thread model according different situation, than realize load balance among several servers. Additional, the system has another two important part: mail list server and log system. Mail list server accomplish administration and receive, send mail list, it is an alone server. The log system record information and provide read interface, it is a window to email system.This thesis talk about large-scale email system's concept, developing situation, infrastructure and software model, describe application server's function and feature, then discuss application server layer, mail list server, log system's design and accomplishment. At last, talk over about the important, shortcomings and develop direction as a sub total.