I have server done using tutorial Perfect Server - there is ISP 3.1.11, Ubuntu 16.04 LTS. Unfortunately my provider gives me IP which regularly is blacklisted. I am going to change this IP. I have an important question to community. Where should I change current IP to this new. I suppose somewhere in postfix, dovecot, dns of domains deployed on the server, /etc/hosts file. Something more and in which files exactly? In /etc/postfix/master.cf I have line smtp_bind_address=127.0.0.1:10025 which is local IP. What about dovecot and another software? PS Is it possible to set only one domain (server hostname) for sending emails for each (clients) domain deployed on the server?