How To Install Postfix on openSUSE

In this tutorial, we will show you how to install Postfix on openSUSE. Postfix is a widely used, powerful, and secure mail transfer agent (MTA) that plays a crucial role in handling email communication on Linux systems. It is known for its performance, security, and flexibility, making it a popular choice among system administrators. In openSUSE, a highly regarded Linux distribution, Postfix is included by default, making the installation process straightforward.

This article assumes you have at least basic knowledge of Linux, know how to use the shell, and most importantly, you host your site on your own VPS. The installation is quite simple and assumes you are running in the root account, if not you may need to add ‘sudo‘ to the commands to get root privileges. I will show you the step-by-step installation of the Postfix mail transfer agent on openSUSE.

Prerequisites

• A server running one of the following operating systems: openSUSE (Leap or Tumbleweed)
• Familiarity with basic Linux commands and openSUSE’s package management system (zypper) is also beneficial, as you’ll be interacting with the command line during the installation process.
• You will need access to the terminal to execute commands. openSUSE provides the Terminal application for this purpose. It can be found in your Applications menu.
• You’ll need an active internet connection to download Postfix and its dependencies.
• You’ll need administrative (root) access or a user account with sudo privileges.

Install Postfix on openSUSE

Step 1. Update the package repositories to ensure you have access to the latest software versions:

sudo zypper refresh
sudo zypper update

Step 2. Installing Postfix on openSUSE.

Now install the Postfix package using the zypper package manager:

sudo zypper install postfix

Once the installation is complete, confirm that the Postfix service is enabled and started by running:

sudo systemctl is-enabled postfix
sudo systemctl status postfix

If the service is not enabled or running, you can start it with:

sudo systemctl enable postfix
sudo systemctl start postfix

To verify the installed Postfix version and default configuration directory, use the following commands:

postconf mail_version
postconf config_directory

The output will display the Postfix version and the location of the configuration files, typically /etc/postfix.

Step 3. Configuring Postfix.

Postfix configuration is stored in two main files: main.cf and master.cf. The main.cf file contains the majority of the configuration options, while master.cf is used for defining custom mail delivery transports. Follow these steps to configure Postfix:

Create a backup of the default Postfix configuration files:

sudo cp /etc/postfix/main.cf /etc/postfix/main.cf.bak
sudo cp /etc/postfix/master.cf /etc/postfix/master.cf.bak

Open the main.cf file in a text editor with root privileges:

sudo nano /etc/postfix/main.cf

Modify the following configuration options according to your requirements:

• myhostname: Set this to your server’s fully qualified domain name (FQDN).
• mydomain: Set this to your domain name.
• myorigin: Set this to $mydomain.
• mynetworks: Specify the trusted client IP ranges that are allowed to send mail through Postfix.
• inet_interfaces: Adjust this to specify the network interfaces on which Postfix should listen for incoming connections.
• mydestination: Set the domains for which Postfix will receive mail.
• home_mailbox: Specify the format and location of user mailboxes (e.g., Maildir/ for Maildir format).
• message_size_limit: Adjust this value if you need to change the maximum message size limit.
• smtpd_recipient_restrictions and smtpd_sender_restrictions: Configure these options to help prevent spam and unauthorized access.

If you require custom mail delivery transports, modify the master.cf file:

sudo nano /etc/postfix/master.cf

Create any lookup tables referenced in the Postfix configuration files.

Restart the Postfix service to apply the configuration changes:

sudo systemctl restart postfix

Step 4. Configuring Firewall.

To ensure that Postfix can receive incoming emails, you need to configure your firewall to allow traffic on the SMTP port (25). Follow these steps to configure the firewall:

sudo firewall-cmd --add-service=smtp

Make the change permanent and reload the firewall:

sudo firewall-cmd --runtime-to-permanent
sudo firewall-cmd --reload

Verify that Postfix can receive incoming connections on the SMTP port by using the telnet command:

telnet your_server_ip 25

Step 5. Testing Postfix.

After installing and configuring Postfix, it’s crucial to test its functionality to ensure that it can send and receive emails properly. Follow these steps to test your Postfix setup:

Use the telnet command to connect to the Postfix SMTP port and verify the response:

telnet localhost 25

You should see the Postfix SMTP banner, indicating that Postfix is listening on the SMTP port.

Send a test email using the mail command-line tool:

echo "This is a test email" | mail -s "Test Email" recipient@idroot.us

Replace recipient@idroot.us with a valid email address where you can receive the test email.

Verify that the email is queued and delivered by checking the Postfix logs:

sudo tail -f /var/log/maillog

Look for lines indicating that the email was queued and delivered successfully.

Congratulations! You have successfully installed Postfix. Thanks for using this tutorial for installing the Postfix mail transfer agent on your openSUSE system. For additional or useful information, we recommend you check the official Postfix website.