I recently switched ISPs and the current one blocks outgoing traffic on port 25. That is to say, all outgoing traffic on that port must be routed through their SMTP server. (I am not happy about it, but I have to live with it for the time being.) By default, postfix under Fedora supplies "username@xxxxxxxxxxxxxxxxxxxxx" as sender. Unfortunately, the ISP's SMTP server rejects messages sent this way; it wants a FQDN. So, I modify these parameters in /etc/postfix/main.cf: myhostname = ariel.lim.nl mydomain = lim.nl myorigin = $mydomain Then run # postfix reload But system mail still get sent out as coming from "colin@xxxxxxxxxxxxxxxxxxxxx" and get rejected. What is going wrong here? I have not enabled any of the masquerade_domains stuff. I'm running FC6/postfix-2.3.3-2 Thanks. -- Colin Brace Amsterdam