MailEnable provides two ways of publishing web mail (or web administration) via the Internet. These approaches are referred to as configuring Host Headers, or a Virtual Directory.
The Host Header option allows web mail (or web administration) to be published through a single IIS web site. When a browser requests the URL, the host name portion of the URL request is mapped to the IIS web site that is publishing the MailEnable web mail (or web administration) application. This approach means web mail can be accessed through a URL like http://webmail.domainname or http://webadmin.domainname. It is recommended to use a host header instead of a virtual directory to avoid conflicts with other applications.