Autodiscover and Exchange 2007
By Joey Masterson
In earlier versions of Microsoft Exchange, deploying and maintaining client access to your Exchange messaging environment was challenging at times. Administrators had to manage user profile settings on all Outlook clients individually. To make the problem worse, corporate mergers and acquisitions necessitated adding new users and reconfiguring their e-mail profiles. This resulted in many extra hours of work for administrators and days of frustration for users while administrators were troubleshooting any problems they encountered.
To ease this burden, Microsoft Exchange Server 2007 includes a new Microsoft Exchange service named the Autodiscover service. The Autodiscover service makes it easier than ever to configure Outlook 2007 clients and maintain reliable access to Microsoft Exchange features such as Unified Messaging (UM), the offline address book (OAB), and the Availability service.
Outlook 2007 and the Autodiscover Service
The Autodiscover service uses a user's e-mail address or domain account to automatically configure the user's profile. By using the e-mail address or domain account, the Autodiscover service provides the following information to the client computer that is running Outlook 2007:
The user’s display name.
Separate connection settings for internal and external connectivity.
The location of the user’s Exchange 2007 server that has the Mailbox server role installed.
The URLs for Exchange features such as free/busy information, UM, and the OAB.
Outlook Anywhere server settings. Outlook Anywhere was formerly known as RPC over HTTP.
So when a user starts Outlook 2007 for the first time, they no longer have to specify any information if their computer is joined to the domain. Outlook 2007 will start, gather the information automatically, log the user on to their mailbox, and begin retrieving information from your Exchange deployment.
Administrators will also be pleased to hear that, when a user's Microsoft Exchange information changes, Outlook automatically reconfigures the user's profile by using the Autodiscover service. For example, a user's mailbox is moved or the client is unable to connect to the user's mailbox or to available Exchange features. Outlook will contact the Autodiscover service and automatically update the user's Outlook profile to include the information that is required to connect to their mailbox to the available Exchange features.
How the Autodiscover Service Works
When you install the Client Access server role on a computer that is running Exchange 2007, a new virtual directory named Autodiscover is created under the default Web site in Internet Information Services (IIS). This virtual directory handles Autodiscover service requests from Outlook 2007 clients and supported mobile devices in the following circumstances:
When a new user account is configured or updated.
When a user periodically checks for changes to the Exchange Web Services URLs.
When underlying network connection changes occur in your Exchange messaging environment.
Additionally, a new Active Directory object named the service connection point (SCP) is created when you install the Client Access server role.
The SCP object contains the authoritative list of Autodiscover service URLs for the forest where Exchange 2007 is installed. For more information about SCP objects, see Publishing with Service Connection Points.
Figure 1 illustrates how a client connects to a Client Access server the first time from inside an internal network.
Figure 1 The Autodiscover service process for internal access
For external access, the client locates the Autodiscover service on the Internet by using the primary Simple Mail Transfer Protocol (SMTP) domain address from the user's e-mail address. Depending on whether you have configured the Autodiscover service on a separate site, the Autodiscover service URL will be either https://<smtp-address-domain>/autodiscover/autodiscover.xml or https://autodiscover.<smtp-address-domain>/autodiscover/autodiscover.xml. Figure 2 illustrates a simple topology with a client connecting from the Internet.
Figure 2 The Autodiscover service process for external access
When the client connects to the Active Directory directory service, the client looks for the SCP object that was created during Setup. In deployments that include multiple Client Access servers, an Autodiscover SCP object is created for each Client Access server. The SCP object contains the ServiceBindingInfo attribute that has the fully qualified domain name (FQDN) of the Client Access server in the form of https://CAS01/autodiscover/autodiscover.xml, where CAS01 is the FQDN for the Client Access server. By using the user credentials, the Outlook 2007 client authenticates to Active Directory and searches for the Autodiscover SCP objects. After the client obtains and enumerates the instances of the Autodiscover service, the client connects to the first Client Access server in the enumerated list and obtains the profile information in the form of XML data that is required to connect to the user's mailbox and available Microsoft Exchange features.
Before You Start
Deploying the Autodiscover service is only one step in making sure that Microsoft Exchange features such as Unified Messaging and the offline address book can be accessed by Outlook 2007 clients. Before you configure your Exchange deployment for the Autodiscover service, you must configure the Exchange services so that they can be accessed by users. For information about how to configure Exchange services for the Autodiscover service, see How to Configure Exchange Services for the Autodiscover Service.
For More Information
Now that you have learned about the Autodiscover service and what it can do for your Exchange deployment and users, you will be better prepared to manage and deploy Exchange 2007. For more information about the topics discussed in this article, see the following:
Microsoft Exchange Server 2007 Help from the Microsoft Download Center
Joey Masterson - Technical Writer, Microsoft Exchange Server