Proxy problem

From: Unknown (anonymous_at_discussions.microsoft.com)
Date: 05/28/04 

Date: Fri, 28 May 2004 05:41:04 -0700

Our configuration looks like this: work station (domain)->ISA server+Proxy (cache mode)->trough HTTP request goes to ISA server, which is in DM zone->PIX to the net.
We cannot set messenger to log in onto .Net account. We tried two different accounts, both active and tested elsewhere. Our IE goes to the internet through Proxy server. Can someone direct us how to configure messenger so he can go through proxy server onto internet and .Net account?