I've installed Fedora Core 5 using the FC5 perfect guide found in this site and ISPConfig on my server. As far as I know, everything works fine. However, I have issues with the way Postfix works on my server. I will try to explain what I needed on the server. I wanted Postfix to be the SMTP server to several domains, either hosted on this machine or another machine, which is on the same IP range, eg. 89.107.17.* My first problem is that when sending email out, Postfix is using the sending domain to identify itself and not the FQDN hostname of the server. This have somehow caused the server IP to be blacklisted by CBL. My questions are :- How do I configure Postfix to use the FQDN hostname of the server to identify itself for all outgoing emails, ie. fc5-g3.iknow-uk.com Allow Postfix to accept and relay emails from specific IP range, eg. 89.107.17.* or from a file containing a list of domains (Pls include the format to use in the file) Allow email users to send emails using the server by authenthication, eg. pop-before-auth, etc... I am not really good with Postfix, so please include as much details as possible. Thanks for any help posted on this thread.