When you change the IP of an "inner" mail server. You need to perform the following:
- Change /etc/postfix/transport (to send the mail to the right server)
- Change /etc/postfix/mynetworks (to be able to forward mail from your new IP)
- postmap transport //Compiles the transport file into transport.db - you don't need to do this for mynetworks
Concepts:
- Change email server IP
- Smart Host for dynamic IP
- smarthost