Applies to: Exchange Server 2007 SP3, Exchange Server
2007 SP2, Exchange Server 2007 SP1, Exchange Server 2007
Topic Last Modified: 2007-08-31
When you use the Enable Outlook Anywhere wizard to configure your Client Access server to provide Outlook Anywhere access, you must select an authentication method for your Outlook clients to use. After you select an authentication method, you can change this method by using the Set-OutlookAnywhere cmdlet in the Exchange Management Shell.
Understanding Authentication for Outlook Anywhere and the /rpc Virtual Directory
When you specify authentication for Outlook Anywhere, you provide the authentication method which will be used by the Outlook 2007 client. This authentication method is automatically provided to the client by the Autodiscover service. Additionally, this is separate from the authentication method on the /rpc virtual directory located on your Microsoft Exchange Server 2003 Client Access servers. By default, in the original release (RTM) version of Exchange 2007, the /rpc virtual directory is enabled for both Basic authentication and Integrated Windows authentication and cannot be modified. In Exchange 2007 Service Pack 1 (SP1), the authentication method on the /rpc virtual directory can be modified by using the Set-OutlookAnywhere cmdlet to be either Integrated Windows authentication or Basic authentication. For more information, see How to Configure Authentication for Outlook Anywhere.
Basic Authentication and Outlook Anywhere
You can use Basic authentication with Outlook Anywhere. Basic authentication requires a user name and password, and then sends the user name and password over the Internet in plain text. As long as you use Secure Sockets Layer (SSL) to help secure the connection between the Microsoft Office Outlook Web Access client and the Microsoft Exchange messaging infrastructure, using Basic authentication with Outlook Anywhere is supported. For more information, see How to Configure Authentication for Outlook Anywhere.
NTLM Authentication and Outlook Anywhere
NTLM is a method of authentication based on Integrated Windows authentication. We recommend using NTLM Authentication. However, if you are using a firewall that does not handle NTLM, you must use Basic authentication over SSL. For more information, see How to Configure Authentication for Outlook Anywhere.