Error message when adding an attachment in Outlook Web Access or Internet Explorer 5: "The page cannot be displayed"

When you add an attachment to a new e-mail message by using Outlook Web Access (OWA), the following error message may be displayed: The following event is logged in the application event log on the Microsoft Internet Information Service (IIS) OWA server: This problem may also occur when you try to open an e-mail attachment by using Microsoft Internet Explorer 5.

This problem may occur because the OWA virtual directory is configured with Microsoft Windows NT Challenge\Response (NTLM) authentication only.

To work around this problem, configure the OWA virtual directory to use Anonymous authentication in addition to NTLM authentication.

Note If IIS and Exchange Server are not located on the same computer, Exchange accesses the directory and the information store differently. The OWA client establishes a MAPI logon to the Exchange Server computer that the client is connected to. When NTLM authentication is enabled on the server that is running IIS, OWA can only access information on the local server. Any attempts to access information on other folders, such as public folders or Schedule+ Free/Busy information will fail. If OWA is installed on the same computer as Exchange Server, confirm that the Allow Anonymous check box and the Windows NT Challenge/Response check box are selected. If OWA is installed on its own server or if your users access OWA from the Internet, make sure that the Allow Anonymous check box and the Basic Authentication check box are selected.

Microsoft has confirmed that this is a problem in Microsoft Outlook Web Access version 5.5.