Applies to: Exchange Server 2007 SP3, Exchange Server 2007 SP2, Exchange Server 2007 SP1, Exchange Server 2007
Topic Last Modified: 2007-04-13

In Microsoft Exchange Server 2007, transport servers rely on the underlying Microsoft Windows HTTP Services (WinHTTP) to manage all HTTP and HTTPS traffic. Both Hub Transport servers and Edge Transport servers may use HTTP to access updates for Microsoft Exchange 2007 Standard Anti-spam Filter Updates and the Microsoft Forefront Security for Exchange Server anti-spam update service, and for certificate revocation list (CRL) validation.

In most organizations, a proxy server is used for HTTP and HTTPS communications with destinations on the Internet. If your organization uses a proxy server and your Exchange Transport servers are not configured to use the proxy server for HTTP and HTTPS, you must configure them so that HTTP-enabled CRL validation works.

The simplest way to configure WinHTTP is to use ProxyCfg.exe. ProxyCfg.exe is a command-line tool that is included in the %System32% directory on all Windows Server 2003 computers. You can use it to set and view WinHTTP configurations.

Before You Begin

To perform this procedure, the account you use must be delegated the following:

  • Local Administrators group

For more information about permissions, delegating roles, and the rights that are required to administer Exchange 2007, see Permission Considerations.


To use ProxyCfg.exe to specify the proxy server in your organization and to specify that all local traffic bypasses the proxy server

  • Run the following command:

    Copy Code
    proxycfg -p proxy_server "<local>"

    This command specifies that HTTP servers and HTTPS servers are accessed through a proxy server named "proxy_server", except for host names that do not contain a period specified by the "<local>" argument.

Even if you are not running a proxy server, we recommend that you use ProxyCfg.exe to check whether a previous proxy has been set. You can view the current configuration by running the tool without arguments, as follows:

Copy Code

To configure a direct Internet connection for WinHTTP or to remove an existing proxy configuration, run the following command:

Copy Code
proxycfg -d 
You must restart the Microsoft Exchange Transport service and the Microsoft Exchange Anti-spam Update service after you have made configuration changes to WinHTTP.

For more information about how to use ProxyCfg.exe, see ProxyCfg.exe, a Proxy Configuration Tool.