Exchange Server 2010 OAB download fails when redirection is configured incorrectly in IIS 7

Microsoft Outlook users cannot download the Offline Address Book (OAB) from a server that is running Microsoft Exchange Server 2010.

This issue can occur if an HTTPS redirection is configured incorrectly in Internet Information Services (IIS) 7. If HTTPS redirection is configured incorrectly, Web.config files may be created in the following locations:

• %programfiles%\inetpub\wwwroot
• %programfiles%\microsoft\exchange server\client access\OAB

To resolve this issue, follow these steps:

1. Remove the Web.config files that are not required. To do this, follow these steps:
   1. Click Start, click Run, type cmd, and then press Enter.
   2. At the command prompt, type the following commands, and press Enter after each command:
      • cd %windir%\system32\inetsrv
      • appcmd clear config "Default Web Site/oab" -section:defaultDocument
      • appcmd clear config "Default Web Site" -section:defaultDocument
   3. Delete the Web.config file in the following file system locations:
      • %programfiles%\microsoft\exchange server\client access\OAB
      • %programfiles%\inetpub\wwwroot
2. Restart the IIS Admin service.
3. Start Internet Information Services (IIS) Manager.
4. Click Default Web Site, and then double-click HTTP Redirect.
5. Click to clear the Redirect requests to this destination check box, and then click Apply.
6. Repeat step 5 for all virtual directories.
7. Reconfigure HTTPS redirection. For information about how to configure HTTPS redirection correctly, see the following article in the Microsoft Knowledge Base:
   975341 How to redirect requests from HTTP to HTTPS or to the OWA virtual directory in IIS 7
   Note When you follow the steps in the "Resolution" section for KB 975341, verify that you click to select the Only redirect requests to content in this directory (not subdirectories) check box.
8. Restart the IIS Admin service.