Research And Implementation Of MAPI-based Mail Pre-fetching Platform

Microsoft Exchange Server is Microsoft’s e-mail service components to provide users with e-mail access, storage, forwarding services. The Exchange Server Supports a variety of e-mail network protocols, and the MAPI protocol is the proprietary protocol that Microsoft Outlook uses to communicate with Microsoft Exchange. Due to the lack of consideration of the large time delay in the wide-area environment, the MAPI protocol uses a large number of packets and too much request/response interactions in the application layer, which make it works inefficiently in wide-area networks. There are many accelerated manufacturers optimized MAPI protocol at home and abroad. Moreover, all of them take the same strategy, which is pre-fetching for mail data when user is sending or receiving mail to improve response speed.This paper proposes a mail pre-fetching mechanism based on transparent prepopulation of MAPI traffic. The transparent prepopulation mechanism sustains Microsoft Exchange MAPI connections between the client and server even after the user has logged out Outlook to pre-fetch mails. This allows mail data to be delivered between the Exchange server and the Mail Perfecting Platform while the Outlook client is offline or inactive. When a user logs into the Outlook client, the mail data has already been pre-fetched to the local, which greatly enhances the transmission speed of mail. Transparent prepopulation can ease the net peak problem when the user logins outlook again and downloads mails. The main research work of this paper can be summarized as follows:This paper analyses the MAPI protocol, including the RPC protocol, the NSPI Address Book protocol, the EMSMDB Message Store protocol, and identity authentication protocols in Exchange. This paper also describes the development process of Mail Perfecting Platform from several aspects, such as requirement analysis, design and implementation of the application proxy gateway and the mail perfecting plug-in and key technologies etc. Finally, the experimental result shows that mails can be pre-fetched between every version of Outlook and Exchange both in the cache and no-cache model, which effectively enhances the transmission performance of main in WAN. There are44figures,5tables and60references in this paper.