Microsoft KB Archive/254998

= XCON: MIME Internet X.400 Enhanced Relay Maps X.400 Address to SMTP Address Rather than Encapsulating X.400 Address in the SMTP Address =

Article ID: 254998

Article Last Modified on 10/26/2006

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APPLIES TO


 * Microsoft Exchange Server 5.5 Service Pack 3

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This article was previously published under Q254998



IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows Registry



SYMPTOMS
If an X.400 user sends a message to an SMTP recipient and to an X.400 recipient and the message is sent to SMTP over an Exchange Server computer that is configured for MIME Internet X.400 Enhanced Relay (MIXER) address mapping but that has no mapping table entry for the X.400 recipient's address, the X.400 address is translated to an SMTP address according to the algorithm that is defined in Request for Comments (RFC) 2156 (MIXER), instead of being encapsulated in the SMTP address of the MIXER server so that replies can be routed back to this server.

For example, if an X.400 user sends a message to both an SMTP recipient and to the following X.400 user

"c=us; a=mci; p=prmd; s=user; g=another"

this user's X.400 address is mapped according to the RFC 2156 algorithm to the address "another.user@prmd.mci.us," which is almost certainly an invalid address for this user. This means that the SMTP recipient cannot reply to the X.400 recipient. The Exchange Server MIXER server should encapsulate the X.400 address to create the following correct reply address:

"/G=another/S=user/P=prmd/A=mci/c=us/"@microsoft.org.com

where microsoft.org.com is the domain address of the MIXER server.



RESOLUTION
To resolve this problem, obtain the latest service pack for Exchange Server 5.5. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

191014 XGEN: How to Obtain the latest Exchange Server 5.5 Service Pack



WORKAROUND
To work around this issue, create a custom recipient for the X.400 recipient on the MIXER server. The SMTP address of the custom recipient can be used instead of the mapped version of the X.400 address.



STATUS
Microsoft has confirmed that this is a problem in Microsoft Exchange Server version 5.5 Service Pack 3. This problem was first corrected in Exchange Server 5.5 Service Pack 4.



MORE INFORMATION
If you want addresses to be translated according to the RFC 2156 algorithm and not encapsulated after you apply this fix, then you need to edit the registry:  WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

 Start Registry Editor (Regedt32.exe). Locate the following key in the registry:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeMTA\Parameters

 On the Edit menu, click Add Value, and then add the following registry value:

Value Name: Strict MIXER Conformance

Data Type: REG_DWORD

Value: 1

 Quit Registry Editor.</li></ol>

Additional query words: MIXER RFC2156

Keywords: kbbug kbexchange550presp4fix kbexchange550sp4fix kbfix kbqfe KB254998

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