If your organization plans to use Microsoft® Exchange Server 5.5 with Microsoft Office Outlook 2003, you should install a critical update for Exchange Server before upgrading client computers to Outlook 2003.

Choosing to use Outlook 2003 with Exchange Server 5.5 without the update can cause Exchange Server to encounter an error and stop responding. The problem occurs in certain scenarios when a rule in a user’s mailbox becomes corrupted; when an e-mail message arrives and this rule is executed, Exchange Server can fail.

To fix this problem, contact Microsoft Product Support Services to obtain an update. The update requires Microsoft Exchange Server 5.5 Service Pack 4 (SP4). For a complete list of support phone numbers, click on Phone Numbers, Support Options and Pricing on the Contact Microsoft - Overview page of the Microsoft Product Support Services Web site.

For more detailed information about this problem, see the Knowledge Base article XADM: Information Store Intermittently Stops Responding and an Access Violation Occurs in EcDSDNFromSz.