I've searched and searched but couldn't find anything on this. I want to make sure certain subnets can deliver ALL mail to our ISPconfig server, but still limit other mail servers. A lot of our customers use a third party SPAM filtering service to clean the mail before even getting to our server. Needless to say, a lot of connections come from their subnets for delivery. Is there a postfix directive to make sure that they NEVER get stopped? Thanks!