Proxy setting -ISA - Webmail timing out
When we try and access our webmail (lancsngfl accounts) i can access it from the proxy server setting the proxy in IE to the upstream proxy it connects fine and allows me to access it. When i set the IE proxy to our local isa server, it won't log in, it comes up with a box saying that it has timed out, and to please log in again.
Does anyone know what ISA setting could be causing this, and where to start troubleshooting it? We're running ISA 2004 Standard edition on Windows Server 2003 R2.