Email Services: Configuring Postfix

10 minutes
  • 2 Learning Objectives

About this Hands-on Lab

Configuring `postfix` is a relatively simple task that will cause email systems to fail if done incorrectly. In this hands-on lab, you’ll be able to practice that configuration and test it in a controlled environment.

Learning Objectives

Successfully complete this lab by achieving the following learning objectives:

Configure the hostname and domain
  1. First, we should check out what our hostname and domain are:

  2. With that information recorded in our notes we can elevate to root and verify postfix is installed:

    sudo -i
    rpm -q postfix
  3. Now we can configure postfix:

    sudo vim /etc/postfix/
  4. Scroll down until we find the myhostname variable. We can set that to “”.

  5. Set the mydomain variable to “”

  6. Search for the mail_spool_directory variable and uncomment the one that says “/var/mail”

  7. Save and quit, then restart postfix.

    sudo systemctl restart postfix
Send a test email to cloud_user

This task requires understanding how email servers communicate.

  1. Enter in the following commands in order to send the email:

    1. telnet localhost 25
    2. ehlo localhost
    3. mail from:
    4. rcpt to: cloud_user
    5. data
    6. Subject: Test email
    7. test
    8. To close out of composing the message, place a . on a new line and press return.
      Then use:
      Ctrl + ] and press return
      Then type:
      close and press return

    9. Check to see that the e-mail sent:

      sudo tail /var/log/maillog

      Look for the current data, and then confirmation that an e-mail was received.

  2. Change to the mail directory:

cd /var/mail/

Additional Resources

As part of your onboarding process, you’ve been tasked with configuring postfix on a new server to be able to receive emails.

Note: You must use the cloud_user local user as the mail recipient.

What are Hands-on Labs

Hands-on Labs are real environments created by industry experts to help you learn. These environments help you gain knowledge and experience, practice without compromising your system, test without risk, destroy without fear, and let you learn from your mistakes. Hands-on Labs: practice your skills before delivering in the real world.

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