Microsoft KB Archive/254214

= XFOR: Routing Restrictions May Not Work with Some Antivirus Solutions =

Article ID: 254214

Article Last Modified on 10/28/2006

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APPLIES TO


 * Microsoft Exchange Server 5.5 Standard Edition

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This article was previously published under Q254214



SYMPTOMS
Routing restrictions may not work after you install Simple Mail Transfer Protocol (SMTP) antivirus software.

When you install SMTP antivirus software, the installation places the Exchange Server Internet Mail Service behind an antivirus 'firewall,' as illustrated in the following diagram:

(Internet) > (SMTP Virus Scanner) > (Exchange Server Internet Mail Service)

In this configuration, the routing restrictions, specifically the options that require a specific IP address or range of IP addresses, may no longer work.

NOTE: Routing restrictions are created on the Routing tab of the Internet Mail Service. A routing restriction is a unit of criteria to allow or restrict incoming SMTP mail.



CAUSE
When an Exchange Server computer running the Internet Mail Service is placed behind an SMTP virus scanner or virus firewall, as illustrated in the diagram in the "Symptoms" section of this article, then the Internet Mail Service actually only accepts connections from the antivirus software. Thus, when the Internet Mail Service processes the message, it records the source computer as 127.0.0.1 (the local host), so the Internet Mail Service never sees all of the other Internet IP addresses.



WORKAROUND
To work around this problem, make sure that the first SMTP daemon, the antivirus firewall, is capable of advanced restrictions.



STATUS
This behavior is by design.



MORE INFORMATION
For additional information, click the article number below to view the article in the Microsoft Knowledge Base:

173903 XFOR: Changing the TCP Port Used for SMTP Mail

This article describes how to configure the Exchange Server Internet Mail Service and an SMTP based virus scanner to work together on the same computer. After you follow the instructions in this article, each product runs on a different port.

For antivirus features, please contact your antivirus software vendor.

Additional query words: antivirus norton symantec port 25 av

Keywords: kbprb KB254214

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