Exchange Server is a complex product, so it's no surprise that there are many things you can do with it when you set it up. You also have the advantage of adding services to Exchange as your organization grows, which will allow your user base to access additional capabilities.
When you first install Exchange 2003, you'll find that it installs and enables some default services that are necessary to support certain basic clients: Outlook 2003, Outlook Web Access and Exchange ActiveSync. But there are a number of services that Exchange will install, but not enable, and you may want these enabled as well. You enable each of them on a virtual server, and you have to assign each virtual server that you generate with a unique set of IP address and port addresses for the service in question.
Microsoft recommends some port settings, but notes that you don't have to use these port settings if you have a reason not to. However, the caveat is that if you don't use the recommended port settings (for example, POP3 has recommended TCP port of 110 and SSL port of 995), then some clients may not be able to connect to the virtual server with the service carrying the non-standard port.
You can use any IP address, however, that's available on any of the available network cards. In that way, you should be able to come up with a unique set of IP address and ports for any given virtual server.
To do this assigning, you have to log on to the server where the virtual server runs with an account that has local admin privileges and full Exchange admin permissions. Then in the Exchange System Manager, click on the protocol you want to assign an IP address or an identity, and select properties, then advanced on the General tab. Now you can either edit the IP address or add a new combination of IP and ports for a new identity of the virtual server.
Exchange System Manager gives you control over many of the functions of the virtual servers. For example, you can limit the number of connections to the server, or start and stop the virtual servers as the situation requires.
For more details, you can download the Exchange 2003 Client Access Guide, which gives detailed information on configuring Exchange 2003 for client access from the Internet or through mobile clients.
David Gabel has been testing and writing about computers for more than 25 years.
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