I have my proxy server set to be used by the majority of my internal users. The problem I am running into is that now that I've upgraded (some time ago) to Exchange Server 2007 I am now having issues between the Outlook 2007 client and the Exchange 2007 server for those users that are configured to pass to the internet through the proxy. The error that shows up just requests for the username and password of the person like it forgot the users credentials that were used to connect to the exchange server. It appears that the emails can be sent and received but it will repeatedly ask users for their credentials. This is not a virus or anything in relation to a malware infection but can be reproduced by turning off the use of the proxy (IE Browser - proxy settings turned off) and outlook will not ask for credentials, and then turn the proxy back on (reverse) and the problem will start again. Let me know if there is a quick fix (port, protocol, acl rule) that can be put into place or an exchange/outlook modification that can be made to resolve this issue.
Thank you, Kale
