XADM: Recipient Update Service Stamps Duplicate Proxy Addresses

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Article ID: 315900 - View products that this article applies to.
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The Recipient Update Service may stamp objects with proxy addresses with conflicting e-mail address proxies. Objects that may be affected include:
  • Mailboxes
  • Mail-enabled users, Contacts, or groups
  • Public folders


E-mail address proxies are run through a uniqueness checker before they are stamped onto the corresponding directory objects. In versions of Exchange that are earlier than Exchange 2000 Server Service Pack 2 (SP2), this uniqueness checker stops looking for additional duplicate proxies after it finds the first duplicate proxy address; therefore, any additional conflicting proxy addresses are accepted and conflicts are created. These conflicts cause duplicate proxy addresses to be created.

In this example, recipient policy for the following sample users is set as follows:
SMTP: @a.com
smtp: @b.com
Active Directory contains objects Y and Z with the following proxies:
Y: SMTP:user2@a.com

Z: SMTP:user@a.com
Proxies are generated for a new object X. The first attempt at generating proxies (before the uniqueness check) produces the following:
X: SMTP:user@a.com
To perform the uniqueness check, Exchange 2000 searches for any object with any of those proxies. One conflict is reported. The uniqueness check determines that these proxies cannot be used because object Y is using user@b.com. Therefore, the proxies are adjusted to:
X: SMTP:user@a.com
The uniqueness checker does not recognize that user@a.com is also not unique because of object Z (the uniqueness checker only looks at Y).


To resolve this problem, obtain the latest service pack for Microsoft Exchange 2000 Server. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
301378 XGEN: How to Obtain the Latest Exchange 2000 Server Service Pack


Microsoft has confirmed that this is a problem in Microsoft Exchange 2000 Server. This problem was first corrected in Microsoft Exchange 2000 Server Service Pack 2.


After you apply Exchange 2000 Server service pack, the uniqueness checker is modified to catch all of the instances of conflicting proxies, instead of just the first instance.

The expected results for the example in the "Cause" section of this article are that the user X is stamped so that all of the proxies are unique:
X: SMTP:user3@a.com


Article ID: 315900 - Last Review: October 24, 2013 - Revision: 2.0
  • Microsoft Exchange 2000 Server Standard Edition
kbnosurvey kbarchive kbbug kbexchange2000sp2fix kbfix KB315900

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