When try to send from any domain between same users in this domain i get " "mail for x.x.x loops back to myself". When send from otrer mailserver i get " NOQUEUE: reject: RCPT from x.x.x ... Relay access denied;. This is centos 5.2 perfect setup. hostname is server1.h.y.z hostname in /etc/hosts and /etc/sysconfig/network is same one. This hostname is in /etc/postfix/main.cf (myhostname= server1.h.y.z) , mydestinatin is mydestination = $myhostname, localhost.$mydomain, localhost, server1.x.y.z. local-host-names are: localhost server1.x.y.z localhost.x.y.z localhost.x.y.z localhost.localdomain .... virtusertable: i see one acc (domain name of ns.x.y.z) with this syntax: firstname.lastname@example.org web15_user email@example.com web15_user (there no record for this domain user@domain, only firstname.lastname@example.org) And others with this syntax: email@example.com web25_user firstname.lastname@example.org web25_user email@example.com web25_user ... I cant understand what is reason for this error.