Setting Up Postfix Email Server

Most monitoring tools can send email notifications, so a local email server is quite helpful for testing. In this post, I used Red Hat Enterprise Linux 8.0 hosted on an Amazon EC2 instance.

First, I installed the postfix package:

    dnf install -y postfix

Then, I edit the /etc/postfix/main.cf configuration file:

    sudo sed -i "s/#myhostname = host.domain.tld/myhostname = $(hostname -f)/" /etc/postfix/main.cf
    sudo sed -i "s/#mydomain = domain.tld/mydomain = ap-south-1.compute.internal/" /etc/postfix/main.cf
    sudo sed -i "s/#myorigin = \$myhostname/myorigin = \$myhostname/" /etc/postfix/main.cf
    sudo sed -i "s/#inet_interfaces = all/inet_interfaces = all/" /etc/postfix/main.cf
    sudo sed -i "s/inet_interfaces = localhost/#inet_interfaces = localhost/" /etc/postfix/main.cf
    sudo sed -i "s/#mynetworks_style = subnet/mynetworks_style = subnet/" /etc/postfix/main.cf

Finally, I send a test email with a CLI email client:

    sudo dnf install -y mailx
    mail ec2-user@ip-172-31-5-199.ap-south-1.compute.internal
    mail
    #1  #Read the first email
    #d 1  #Delete the first email
    #q  #Quit the application