This update addresses the vulnerability addressed in the Microsoft Windows Security Bulletin MS04-002.

A security issue has been identified that could allow one user to randomly access another user's mailbox. To be protected against this problem, it is only necessary to install this update on Microsoft Exchange 2003 front end servers. However, Microsoft recommends that you install this update on all Microsoft Exchange 2003 servers in your organization. If you do so, then all servers will already be protected in case they are ever designated as front end servers.

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