Installing and Configuring Postfix on CentOS

This section outlines the steps to install and configure Postfix on the CentOS systems.

1. Ensure that all of your system packages are up-to-date by running the following command:

   sudo dnf update -y

2. To install Postfix, use the dnf package manager:

   sudo dnf install postfix

3. Once the installation is complete, start and enable Postfix to run on boot:

   sudo systemctl start postfix

   sudo systemctl enable postfix

4. To configure postfix, edit the main Postfix configuration file using your preferred text editor:

   sudonano /etc/postfix/main.cf

5. Find and modify the following values to match your domain and desired setup:

   myhostname = mail.example.com
   mydomain = example.com
   myorigin =$mydomain
   inet_interfaces = all
   mydestination =$myhostname, localhost.$mydomain, localhost, $mydomain
   mynetworks =127.0.0.0/8
   home_mailbox = Maildir/
   smtpd_banner =$myhostname ESMTP $mail_name

   Replace 'example.com' with your actual domain name. Once done, reload Postfix to apply the changes:

   sudo systemctl reload postfix

   Note: For more information on testing Postfix, see https://reintech.io/blog/install-configure-postfix-centos-9.