My Exchange 2000 server is on the same machine as my ISA/w2000 server. When ISA is active, po3 service starts but stops soon after and is unstartable, even rebooting does not fix it. When ISA is inactive it is okay. What can I do to stop this? Outlook 2000 will not check email from my email account (@yahoo.com) when ISA is running but does fine when it is not. Can someone PLEASE leave step by step instructions for stuff instead of saying 'you can do this or that' without saying how? thanks dp