Hi, I'm currently trying to implement a postfix setup which does the following so that our different companys can email out from the correct domainname for each company : - has 5 separate IP addresses (separate NICs) - needs 5 separate postfix instances - 1 per IP (each IP has its own domainname) - just relaying email from internal network - all running on one Red Hat box I've done a search but it I'm confused between the postfix multi function and just separate instances of postfix. The separate instances is preferable but does anyone have any pointers on how to set this up please. I've trawled through the postfix manual but its not obvious. Thanks onion