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HTTP 401 or 404 error messages when you access OWA implicitly or explicitly
Article ID: 293386 - View products that this article applies to.
This article was previously published under Q293386
Note The error condition that is described in this article may occur for many reasons. The issue and the error messages that are described in this article are applicable only to the problem as stated in the "Symptoms" section and only with the products that are listed in the "Applies to" section. If the "Symptoms" and the "Applies to" sections do not apply to your computer, you must repeat your search with different criteria to find content that applies to your issue.
When you try to log on to Outlook Web Access (OWA) implicitly (that is, you do not append the URL with your alias), you may receive one of the following error messages:
Error Message 1
HTTP/1.0 401 Unauthorized
Error Message 2
Error: Access is denied.
Error Message 3
When you examine the Microsoft Internet Information Services (IIS) log files, you will see a 401.5 error code. The IIS log files are typically found in the Windows\System32\LogFiles\W3SVC1 directory.
Page Not Found
When you try to log on to OWA explicitly (that is, you append the URL with your alias), you may receive the following error message:
When this issue occurs, you can still access your mailbox by using the Microsoft Outlook MAPI client.
- HTTP 404 - File not found
This issue occurs if the user account that you used to log on to OWA does not have an appropriate Simple Mail Transfer Protocol (SMTP) address.
This issue generally occurs when you move users from a Microsoft Exchange Server 5.5 computer to a Microsoft Exchange 2000 Server or Microsoft Exchange Server 2003 computer, or when you upgrade an Exchange 5.5 computer to Exchange 2000 or Exchange 2003 and the default naming policy in your Exchange 2000 or Exchange 2003 organization is different from the naming policy in the Exchange 5.5 site.
This is a core Web Distributed Authoring Version (DAV) architectural issue. To find the mailbox that is associated with a URL, DAV uses the values in the proxyAddresses attribute of the user object, and then compares these values against the domain and the Exchange virtual directory to find a match with a unique object in the directory.
See the "More Information" section for information about how to determine the appropriate SMTP address and the default e-mail proxy address that is generated by Exchange 2000.
Note The Web DAV address check is not present in Microsoft Exchange 2003 Service Pack 1.
Exchange 2003To resolve this issue, obtain the latest service pack for Exchange Server 2003. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
836993Note Installing Microsoft Exchange Server 2003 Service Pack 1 (SP1) resolves this issue only if users log on to OWA implicitly. If users log on to OWA explicitly, they may still receive the following error message:
(http://support.microsoft.com/kb/836993/ )How to obtain the latest service packs for Exchange Server 2003
- HTTP 404 - File not found
Exchange 2000To resolve this issue, use one of the following methods:
Method 1: Modify or add an SMTP address to a user
Note The default (bold) SMTP address of a user does not have to match the Mailboxes For value. The user should be able to log on if any one of the SMTP addresses match the value.
Method 2: Modify the SMTP domain that is serviced by the Exchange virtual directoryIn the Properties dialog box for the Exchange virtual directory, the Modify button is not available (appears dimmed). This behavior occurs because the SMTP domain that is used by the Exchange virtual directory is always the default SMTP domain that is assigned by the Default Recipient Policy.
To modify the default SMTP domain, follow these steps.
Note These steps include restarting the Microsoft Exchange information store and its dependent services. While the information store is stopped, no clients can access e-mail.
Method 3: Create additional virtual directories for additional SMTP domainsNote If the computer uses front-end servers and back-end servers, you must create the virtual directories on both the front-end servers and the back-end servers.
http://www.microsoft.com/technet/prodtechnol/exchange/2000/maintain/exrecip.mspxTo customize authentication methods, click the Authentication button on the Access tab of Exchange System Manager.
To determine the appropriate SMTP address, follow these steps:
Article ID: 293386 - Last Review: October 25, 2007 - Revision: 9.5