Article ID: 244523 - View products that this article applies to.
This article was previously published under Q244523
Consider the following scenario:
This problem may occur if named pipes (ncacn_np) is used as the Microsoft Exchange Client remote procedure call (RPC) protocol.
To resolve this problem, use one of the following methods:
RPC that uses named pipes (ncacn_np) establishes its security identity by using the credentials of the user who is logged on to the Windows NT domain. Because named pipe connections are established by the redirector to the server, the security identity is established before RPC communication. Therefore, RPC uses the security context that is established by the redirector, and the dialog boxes generated by Microsoft Outlook that request security credentials do not override this security context. Because the user who is logged on does not have permissions for the target mailbox, the logon process to that mailbox does not work.
You can specify the ncacn_np protocol sequence by modifying the RPC_Binding_Order registry value. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
163576Occasionally the named pipes protocol sequence is used because other protocol sequences did not work.
(https://support.microsoft.com/kb/163576/ )Changing the RPC binding order
Other protocol sequences in the RPC_Binding_Order value may not work if either the Exchange Server directory service or information store service is configured to use a static port that is being used at the time that the service starts. This prevents the service from binding to that port and basically disables that protocol for use with that service. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
(https://support.microsoft.com/kb/176466/ )TCP ports and Microsoft Exchange: In-depth discussion
Article ID: 244523 - Last Review: December 29, 2006 - Revision: 5.1
Retired KB Content Disclaimer
This article was written about products for which Microsoft no longer offers support. Therefore, this article is offered "as is" and will no longer be updated.