Using MS Exchange or Other SMTP Mail Servers with Proxy Server 1.0

ID: Q164141

The information in this article applies to:

Microsoft Proxy Server version 1.0

SYMPTOMS

You cannot install or use an SMTP server with Proxy Server 1.0.

CAUSE

If the SMTP server is installed on a different system and behind the Microsoft Proxy Server, it will not be able to receive connections from the Internet. Mail servers need to listen for connections from the Internet in order to exchange mail with other mail servers. The proxy blocks these connections. The Microsoft Proxy Server only permits outgoing connections.

WORKAROUND

To work around this problem, do one of the following:

Install the mail server on same system as Proxy Server 1.0. It will be exposed to all networks that the proxy server is connected to.

Install the mail server on another computer that is directly connected to the Internet. Mail clients on the Intranet will be able to connect with POP or SMTP through the Proxy server.

Upgrade to Microsoft Proxy Server 2.0. This version of Proxy Server allows placement of Microsoft Exchange Server or any other mail server behind the proxy server.

For additional information, please see the following article in the Microsoft Knowledge Base:
Q176771 Using Packet Filters with Exchange Server

Because it is good practice to minimize the number of services running on the proxy server, the first option is the preferred method. Extra services on the proxy server provide more points of access for attack from potential intruders.

Keywords : prodprx1
Version : winnt:1.0
Platform : winnt
Issue type : kbprb