Part 1. Installing and configuring Postfix. Configuring DNS server
If you want that service Postfix works, you need to create various resource records in the DNS server. In this case, I’m using Bind9 as a DNS service. To install and configure bind service there are some videos:
How to install a DNS service in a Linux System: https://www.youtube.com/watch?v=1UAmIyY-L3M
How to configure a forward DNS zone using BIND software: https://www.youtube.com/watch?v=uOM25Q68h00
How to configure a DNS master reverse zone in a Linux System with BIND software: https://www.youtube.com/watch?v=_SQPnvIlFTY
by Miquel Boada
linux dns server