We have an ISA server with Exchange 2000 sitting behind it. We are using the system accounts on the Exchange server. When we implement the use of groups to restrict Internet access, we are unable to receive incoming mail. OWA and outgoing mail works fine, but incoming stops. We changed the services on the Exchange service to use a specified account, but then www service failed to start. Any ideas on how we can implement group restrictions yet still have full email flowing? Thanks