This article was previously published under Q247335
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
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
This issue can occur if Outlook Express cannot authenticate you using Proxy Server and Access Control is enabled for Web Proxy.
To work around this issue, use one of the following methods:
Disable Access Control for Web Proxy.
Configure Internet Explorer and Outlook Express to not use a Proxy server. Instead, use the Winsock Proxy client.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.