Currently Exchange recommends that the Autodiscover service be separated from the default Web site on the Client Access Server (CAS) server if it is heavily used.

To host the Autodiscover service on a separate site but on the same computer as other Exchange features, you must follow these steps in order:

  1. (Required) Configure the SSL certificate - Configure a valid SSL certificate from a CA that the client computer trusts.
  2. (Optional) Create a separate site to host the Autodiscover service - This step is recommended if your SMTP address domain experiences high traffic. For example, consider a situation where your main Web site is and your SMTP address is In this case, we recommend that you host the Autodiscover service on a separate site. Create an Autodiscover virtual directory under a different Internet Information Services (IIS) Web site by using the New-AutodiscoverVirtualDirectory cmdlet.
  3. (Optional) Remove the default Autodiscover virtual directory - If you have decided to host the Autodiscover service on a separate site, you must delete the Autodiscover virtual directory that was created by Setup on the default Web site in Internet Information Services (IIS) by using the Remove-AutodiscoverVirtualDirectory cmdlet.
  4. (Required) Create a new Autodiscover virtual directory in IIS - For the Autodiscover service by running the following command:
  5. New-AutodiscoverVirtualDirectory -Websitename <websitename> -BasicAuthentication:$true -WindowsAuthentication:$true.