Integration with IIS

In previous versions of Exchange, the Information Store process managed the databases and the client access protocols, such as HTTP. In Exchange 2000, the Internet access protocols are removed from Information Store and are now managed by the Internet Information Services (IIS) process. This affects Exchange HTTP virtual servers in the following ways:

• Installation of IIS is required; you must install IIS before using Exchange HTTP virtual servers.
• The default Web site provided by IIS appears in Exchange as Exchange Virtual Server. You cannot manage this virtual server from System Manager; you must administer this virtual server in IIS.
• You can add virtual servers that provide access to mailboxes only from System Manager. If you add a virtual server in IIS, the server only provides access to public folders.

When do I use IIS to manage Exchange HTTP servers?

The best practice for administering HTTP servers created in Exchange is to use System Manager instead of IIS when applicable; for example, you can set authentication methods in both Exchange and IIS. You should only administer authentication from System Manager if you create the HTTP server in Exchange.

Important   The reason for this rule is that Exchange stores HTTP virtual server settings in Active Directory Service and IIS stores its settings in a local configuration file called the metabase. The HTTP server settings in Exchange are periodically written from the Directory Service to the IIS metabase. The settings that you can modify in System Manager are copied into the metabase and will overwrite any changes made using IIS.

For example, you use basic authentication on the HTTP server when you create it in Exchange. Later, you want to choose a more secure authentication method, so you set digest authentication in IIS. However, as soon as Active Directory Service copies the Exchange setting of basic authentication to the metabase, the digest setting is overwritten.

System Manager includes most of the settings you need to configure an HTTP virtual server or directory without using IIS; however, there may be additional IIS features that you want to take advantage of. The important thing to remember is that if the setting is available in both Exchange and IIS, always use System Manager. Changing the setting in IIS is a temporary solution, because the settings are reset to the Exchange values when Active Directory Service updates the metabase.

Settings that should not be modified in IIS include those related to Home Directory, access rights, authentication methods, and script executable permissions, in addition to certain virtual server-specific options.