this was a reply for RoadClosed,

yes, you are right i dont know about mail technologies. but i do know about my network. but not that knowledgeable like you do. i wont start my mail server unless i get the appropriate security and correct configuration of a mail server. yes my router is doing a DHCP on the networks and some of the workstations here doesnt start without ip address assigned. short for a problem on my network - we have to assign ip addresses even though it is already on a DHCP for the computer to have network and internet connection.