Configuring a domain-wide mail service with Postfix

Postfix is a Mail Transport Agent (MTA) responsible for the transfer of e-mails between mail servers using the SMTP protocol. Postfix is now the default MTA on CentOS 7. Here, as with most other critical network services, its default configuration allows outgoing but does not accept incoming network connections from any host other than the local one. This makes sense if all you need is a local Linux user mailing system and for sending out mails to other external mail servers from localhost too. But if you want to run your own centralized mail server for your own private network and domain, this is quite restrictive. So the purpose of this recipe is to set up Postfix as a domain-wide mail service to allow e-mails sent from any host in your network and if the recipient is a valid e-mail address within your local domain, deliver them to the correct mailbox on the mail server.

Getting ready

To complete this recipe, you will require a working...