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Introduction to the Sample Gateway

Exchange Server 2003

Introduction to the Sample Gateway

This content is no longer actively maintained. It is provided as is, for anyone who may still be using these technologies, with no warranties or claims of accuracy with regard to the most recent product version or service release.

In its simplest form, a gateway is an interface that connects one electronic messaging system to another electronic messaging system that has a different message and address format. The gateway receives the e-mail message, translates it from one format to the other, maps addresses between the two systems, and then delivers the translated message.

The topics in Introduction to the Sample Gateway describe the components and tasks of gateways that run on computers using the Microsoft® Windows® 2000 Server operating system. These gateways can be installed on a Microsoft Exchange server or client computer. Gateways that were run with earlier versions of Exchange Server were pure MAPI client applications. Under Exchange 2000 Server, however, a gateway stores configuration and recipient information in Microsoft Active Directory®. This means that while the gateway can still use MAPI to communicate with Exchange 2000, it must use Active Directory® Service Interfaces (ADSI) to interact with Active Directory. The gateway uses MAPI to access MAPI folders, transports, and other MAPI-based services.

You can use gateways in scenarios such as the following:

  • Between e-mail systems within a single organization: Your company has been using another messaging system for years and now plans to convert to Exchange 2000 Server. You can avoid business disruption by installing a gateway to connect the old and new e-mail systems. With the gateway, you can gradually retrain and migrate your current users to Exchange 2000 Server, upgrade their systems, and add new users to the system. During the migration process, all employees will be able to communicate by e-mail. In this scenario, the old e-mail system is the foreign system connected by the gateway.
  • Between an organization and an external e-mail system: Your users must be able to send messages from Exchange 2000 Server to users on another messaging system, such as Internet mail. In this scenario, you must install a gateway that translates messages and addresses from the Exchange format to the format of the other messaging system.
Note  These two scenarios are architecturally identical. In both cases, Exchange 2000 Server uses a gateway to transfer messages to and from a messaging system that is external to it. In the first scenario, it makes no difference that the external system is part of the same organization as Exchange 2000 Server, or that the external system is probably connected over a LAN rather than over the Internet.

The Exchange 2000 Sample Gateway provides a fully functional Sample Gateway and the tools for creating gateways of your own. You can use the code as a basis for your own gateway because the Sample Gateway supports much of the same functionality that all gateways should support.

The following topics provide more detailed information about the Sample Gateway:

Gateway Components

Gateway Tools