Challenges Implementing Autodiscover

One of our visitors recently asked whether there are any challenges with implementing Auto Discover effectively, and Owen, our resident expert, had this to say:

The simple answer, the setup can be as simple or as complex as your corresponding Exchange environment. In a simple Exchange 2007 scenario, where Exchange routes for only one domain, the setup is fairly straightforward. As part of the Exchange 2007 CAS server installation, the necessary Autodiscover components are installed by default on the CAS server, and corresponding SCP records created in Active Directory. For users connecting from remote systems, such as laptops or home computers, an external DNS record is required which directs requests to autodiscover.yourdomain.com to the external address of the Exchange 2007 CAS server.

For more complex Exchange 2007 implementations, with multiple email domains, many external users, and custom SSL certificates, there are a few issues to overcome. Microsoft recommends that a separate website be created for a heavily utilized Autodiscover service. For multiple email domains, individual DNS records for each email domain need to be directed to one common HTTP based URL, which should to be configured to redirect all requests to an HTTPS enabled CAS server hosting the Autodiscover web site. This allows the use of multiple email domains, but one common Autodiscover site and corresponding SSL certificate. Otherwise, individual Autodiscover websites would need to be created on the CAS server, each with individual SSL certificates, which would become cumbersome and expensive to manage.

As Exchange 2007 has introduced a new web based delivery mechanism for Offline Address Books (OABs) for Outlook 2007 clients, replacing the Public Folder method used for Outlook 2000 through 2003 clients, a fully functioning Autodiscover service is required to maintain full functionality for Outlook 2007 clients. The same is true for Unified Messaging and Availability services, therefore a good understanding of and well designed Autodiscover implementation is key to a successful Exchange 2007 deployment.

For further information, Microsoft has published a good description on their TechNet site that describes the various scenarios, and potential solutions.