XCON: Routing Issues with Microsoft Exchange Server, Version 5.0

ID: Q176046

The information in this article applies to:

Microsoft Exchange Server, version 5.0

IMPORTANT: This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore it if a problem occurs. For information about how to do this, view the "Restoring the Registry" Help topic in Regedit.exe or the "Restoring a Registry Key" Help topic in Regedt32.exe.

SYMPTOMS

A message from a Microsoft Exchange user to a recipient on a remote X.400 system may be routed to a local recipient. This can happen if the address of the local recipient and the recipient on the remote X.400 system are similar. For example, if the local recipient has the following X.400 address:

C=US;A=PTT;P=COMPANY;S=USER1

and the remote X.400 recipient has the following address:

C=US;A=PTT;S=USER1

Note that the remote address matches the address of the local recipient, except that there is no Private Management Domain (P=...) defined. Both addresses are syntactically correct and valid.

CAUSE

Microsoft Exchange Server version 5.0 uses a slightly different algorithm for address resolution. Even if the Allow fuzzy proxy search registry key is disabled, Exchange Server still uses a fuzzy algorithm in certain cases.

STATUS

Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 5.0. This problem has been corrected in the latest U.S. Service Pack for Microsoft Exchange Server version 5.0. For information on obtaining the Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

S E R V P A C K

RESOLUTION

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys and Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it. If you are running Windows NT, you should also update your Emergency Repair Disk (ERD).

To resolve this problem, apply the fix referenced below. You will also need to create a new entry in the Windows NT registry. To do this:

Start the Windows NT Registry Editor.

Go to the following subkey:

\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeMTA\ Parameters

Create the following new registry value:
Allow fuzzy proxy search
Set this value to 2. This case-sensitive registry value is a DWORD type value.

If this registry value does not exist in the registry, the Microsoft Exchange Server message transfer agent (MTA) assumes a value of 1 for this setting and enables fuzzy proxy searches.

This value has three possible settings:

Allow fuzzy proxy search=0. Restricted fuzzy proxy searches are allowed. A unique match on the Surname and the Given Name or an exact match is allowed.

Allow fuzzy proxy search=1. Full fuzzy proxy searches are allowed.

Allow fuzzy proxy search=2. No fuzzy proxy searches are allowed at all, only an exact match is allowed.

REFERENCES

For additional information about the fuzzy proxy search in Microsoft Exchange Server, click the article number below to view the article in the Microsoft Knowledge Base:

Q159184 XADM: MTA Does Not Deliver Messages with High Directory Service Activity

NOTE: Be aware that the registry settings are different for Exchange Server version 4.0.

Additional query words:

Keywords : kbbug5.00 kbfix5.00.sp2 XCON
Version : winnt:5.0
Platform : winnt
Issue type : kbbug