XWEB: Unable to Log On to OWA because of Ambiguous Mailbox Names

• Microsoft Exchange Active Server Components, version 5.0
• Microsoft Outlook Web Access, version 5.5
• Microsoft Outlook Web Access, version 5.5 Service Pack 1

SYMPTOMS

When you attempt to log on to an Outlook Web Access (OWA) client, you may encounter the following error message:

HTTP Error 401
401.1 Unauthorized: Logon Failed

This error indicates that the credentials passed to the server do not
match the credentials required to log on to the server.

Please contact the Web server's administrator to verify that you have
permission to access the requested resource.

-or-

Failed to get Inbox.

CAUSE

This problem may occur because of a problem with ambiguous name resolution. In the case that there are two or more ambiguous Exchange Server mailboxes aliases, the log on cannot be resolved correctly.

For example, if there are two mailboxes with aliases such as JohnA and JohnAa, the ambiguity of the aliases cannot be resolved by OWA.

RESOLUTION

When creating domain accounts, administrators should try to avoid using names with similar prefixes and repeating suffixes. Try to create unique Windows NT domain logon names as well as Exchange Server mailbox alias names.

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article.

Keywords :
Version : WINDOWS:5.0,5.5,5.5SP1
Platform : WINDOWS
Issue type : kbbug