Although Exchange Server 2010 continues to support public folders, public folders are no longer required for access to the global address list or the offline address book (OAB).Exchange now provides these features through a Web-based distribu¬tion point. Microsoft Office Outlook 2007 and later clients use the Web-based distri¬bution point for the global address list and the offline address book automatically.
Every Exchange organization has a default OAB and one or more additional custom OABs. Each OAB has a designated Mailbox server, referred to as the genera¬tion server
, responsible for creating and updating that particular OAB.The Microsoft Exchange File Distribution service running on a Client Access server is responsible for gathering the OAB data and keeping the content synchronized with the content on the Mailbox server.
The OAB virtual directory is the Web-based distribution point for the OAB. By default, when you install a Client Access server, this directory is created on the default Web site in Internet Information Services (IIS) and configured for internal access. You can specify an external URL as well.
Outlook 2007, Outlook 2010, and some mobile devices use the Autodiscover service to automatically configure themselves for access to Exchange. The Autodis¬cover service runs on a Client Access server as well and returns the correct OAB URL for a particular client connection.
When you install a Client Access server, an Autodiscover virtual directory is created on the default Web site in Internet Information Services (IIS) and an internal URL is set up for automatic discovery and other features, such as the OAB (which can be automatically discovered as well).
For external users who are running Outlook 2007 or later clients, for Outlook Anywhere to be automatically configured by using the Autodiscover service you must install a valid Secure Sockets Layer (SSL) certificate on your Internet-facing Client Access server that includes both the common name, such as mail.cpandl.com, and a Subject Alternative name for the Autodiscover service, such as autodiscover.cpandl.com. You also need to configure the external URLs for the offline address book, Exchange Web Services, and Outlook Anywhere.
To configure the external URL for the OAB, you can use the –ExternalUrl param¬eter of the Set-OABVirtualDirectory cmdlet. In the following example, you set the OAB external URL and configure it for use with SSL: Set-OABVirtualDirectory -identity "CASServer01\OAB (Default Web Site)" -externalurl https://mail.cpandl.com/OAB -RequireSSL:$true
To configure the external URL for Exchange Web Services, you can use the –ExternalUrl parameter of the Set-WebServicesVirtualDirectory cmdlet.In the following example, you set the Exchange Web Services external URL and configure it for use with basic authentication: Set-WebServicesVirtualDirectory -identity "CASServer01\EWS (Default Web Site)" -externalurl https://mail.cpandl.com/EWS/Exchange.asmx -BasicAuthentication:$True
To configure the external host name for Outlook Anywhere, you can use the –ExternalHostname parameter of Enable-OutlookAnywhere.In the following example, you set the external host name and configure Outlook Anywhere for basic authentication: Enable-OutlookAnywhere -Server CASServer01 –ExternalHostname "mail.cpandl.com" -ExternalAuthenticationMethod "Basic" -SSLOffloading:$False
Once you’ve configured the Autodiscover service and the required URLs, you can test Autodiscover by using Test-OutlookWebServices.Here is an example: Test-OutlookWebServices -ClientAccessServer "CASServer01"