Autodiscover Service Returns Unexpected Values for Outlook Anywhere Proxy Settings

Microsoft Exchange Server 2007 will reach end of support on April 11, 2017. To stay supported, you will need to upgrade. For more information, see Resources to help you upgrade your Office 2007 servers and clients.


This topic explains how to use the Exchange Management Shell to modify Outlook Anywhere settings for the Autodiscover service so that Microsoft Office Outlook 2007 users no longer receive an unnecessary logon prompt. The issue relates to a logon prompt that an Outlook 2007 user receives even though they have been configured to use NTLM authentication. Outlook 2007 users should not receive the logon prompt when they have NTLM authentication configured.

When Outlook 2007 users connect to Exchange by using Outlook Anywhere, the Autodiscover service finds the values for the ExternalHostName and Auth Package parameters of the OutlookAnywhere and OutlookProvider objects in Active Directory. (The OutlookProvider object provides configuration for Outlook 2007 clients.)

However, if the value of the Server attribute is set incorrectly for the EXPR OutlookProvider object, this setting overrides the default service discovery mechanism used by the Autodiscover service. EXPR is one of the Outlook providers that can be managed by using the cmdlets, Get-OutlookProvider and Set-OutlookProvider in the Exchange Management Shell. The Server attribute for the OutlookProvider object should remain at its default setting of $null. You can check the value of the Server attribute by running the Get-OutlookProvider cmdlet (Get-OutlookProvider Identity | format-list).


You can resolve this issue by changing a server-side setting for Outlook Anywhere. Set the value for the Server attribute for the EXPR OutlookProvider object to $null for the Outlook Anywhere configuration settings for the Autodiscover service. You change the setting for the Exchange 2007 server that is running the Client Access server role.

Before You Begin

To perform this procedure, the account you use must be delegated the Exchange Organization Administrator role. For more information about permissions, delegating roles, and the rights that are required to administer Exchange 2007, see Permission Considerations.


To use the Exchange Management Shell to modify Outlook Anywhere settings for the Autodiscover service for the EXPR Outlook Provider object

  • Run the following command:

    Set-OutlookProvider EXPR -Server $null

To see changes apply immediately, restart Internet Information Services (IIS) or recycle MSExchangeAutodiscoverAppPool on the Exchange server that runs the Client Access server role for this change to take immediate effect. To recycle MSExchangeAutodiscoverAppPool, which is the application pool for the Autodiscover service on the Exchange Client Access server, follow these steps:

  1. Open the Internet Information Server Management console.

  2. Expand the Application Pools container.

  3. Right-click MSExchangeAutodiscoverAppPool, and then click Recycle.


    The application pool will be recycled. However, you will not receive any notification.

For More Information

For detailed syntax and parameter information about the cmdlets, see Get-OutlookAnywhere and Set-OutlookProvider.