In the GWIA (GW8sp1) settings under "Access Control", "Settings", Default Class of Service, we are trying to block SMTP access for a subnet, but it does not appear to be working. We can block individual IP addresses, but not a subnet. Is this possible and if so perhaps we are entering the subnet address incorrectly? We want to prevent all LAN stations from direct access to Port 25 on the GWIA while allowing, of course, any external systems to get to Port 25 for incoming email. GWIA is on the Local LAN and not in a DMZ. Thanks.