MS OUTLOOK 2007 is not working with ISA Client 2000 / 2004 on VIST

[Asim Ibrahim]

My MS Outlook 2007 is not working when I connect my laptop / desktop with my
ISA Server and I have used both ISA Server Client 2000 and 2004 but the
problem is still there. Actually, MS Outlook 2007 is rejecting my
send/received request immediately and amazingly same laptop is working fine
on direct internet connection. I am downloading my email directly from my
webmail account and I have no complicated policy installed on ISA Server or
my Windows Server. I have following configuration;
Server Side:
1. MS Windows Server 2003 Enterprise (SP2)
2. MS ISA Server 2000 Enterprise (SP2)

Client Side:
1. Windows Vista Home Premium
2. MS Outlook 2007
3. ISA Server Client 2000 / 2004.

Email account information;
Email address = (e-mail address removed)
POP3 = mail.gaenergy.com
SMTP = mail.gaenergy.com

Error 1:
Task '(e-mail address removed) - Receiving' reported error (0x800408FC) : 'The
server name you entered cannot be found on the network (it might be down
temporarily). Verify that you are online and that the server name is
correct.'

Error 2: Reported error (0x800CCC0D) and 0x80040900

If you need anything else for solution please ask me without hesitation.

Regards,

Asim Ibrahim
(e-mail address removed)
(e-mail address removed)