CAUSE
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
smtp:user@b.com
Z: SMTP:user@a.com
smtp:user2@b.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
smtp:user@b.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
smtp:user3@b.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).
RESOLUTION
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