For information about the differences between Microsoft Outlook Express and Microsoft Outlook e-mail clients, click the following article number to view the article in the Microsoft Knowledge Base:
257824 OL2000: Differences Between Outlook and Outlook Express
SYMPTOMS
When you try to use Microsoft Outlook Express 5.0 to connect to a Hotmail e-mail account, you may receive one or more of the following error messages:
Unable to poll for new mail messages on your HTTP server. Account 'Hotmail', Server 'http://services.msn.com/svcs/hotmail/httpmail.asp', Protocol HTTPMail, Server Response: 'Proxy Authentication Required', Port 0, Secure (SSL): No, Error Number: 0x800CCC37
Outlook Express
Your proxy requires you to authenticate. Contact your network administrator for assistance.
Outlook Express Clients using an ISA server as a Firewall and Web proxy server may see the following error:
Unable to poll for new messages on your HTTP server. Account: 'Hotmail', server : 'http://services.msn.com/svcs/hotmail/httpmail.asp',Protocol" HTTPMail, Server Response: 'Proxy Authentication Required (The ISA server requires authorization to fulfill the request. Access to the Web Proxy service is denied. )', Port: 0, Secure(SSL): No, Error Number: 0x800CCC37