i had added all account in the active domain users and also in ISA protocol rules and content rules .. Proxy Authentication Required ( The ISA Server requires authorization to fulfill the request. Access to the Web Proxy service is denied. ) Configuration: Account: Hotmail Server: http://services.msn.com/svcs/hotmail/httpmail.asp User name: dallience Protocol: HTTPMail Port: 0 Secure(SSL): 0 Code: 800ccc37