How to Disable Outlook Web Access for Specific Users
You can prevent specific users from inside your organization from accessing Outlook Web Access. You do this by disabling the HTTP and NNTP protocols for those users.
Procedure
To disable Outlook Web Access for specific users
In Active Directory Users and Computers, open the user's Properties dialog box.
On the Exchange Features tab, clear the settings for HTTP and NNTP.
For More Information
For detailed steps for how to enable Outlook Web Access for internal clients only, see How to Enable Outlook Web Access for Internal Clients Only.
For information about managing and configuring Outlook Web Access, see the following topics: