How to install Postfix on Linux

Install Postfix on CentOS 7

To install Postfix on CentOS 7, follow these steps:

Open a terminal or login to your server via SSH as a root user.

Update your system packages by running the following command:

yum update

Install Postfix using the following command:

yum install postfix

Start the Postfix service using the following command:

systemctl start postfix

To make sure Postfix starts automatically after a server reboot, run the following command:

systemctl enable postfix

By default, Postfix listens on port 25 for incoming mail. If you’re running a firewall on your server, make sure to open port 25 by running the following command:

firewall-cmd --permanent --add-port=25/tcp
firewall-cmd --reload

That’s it! Postfix should now be installed and running on your CentOS 7.9 server. You can test it by sending an email to a valid email address from your server’s command line using the mail command, for example:

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

Installing Postfix on CentOS 8, Almalinux, Rocky

Open a terminal or login to your server via SSH as a root user.

Update your system packages by running the following command:

dnf update

Install Postfix using the following command:

dnf install postfix

Start the Postfix service using the following command:

systemctl start postfix

To make sure Postfix starts automatically after a server reboot, run the following command:

systemctl enable postfix

By default, Postfix listens on port 25 for incoming mail. If you’re running a firewall on your server, make sure to open port 25 by running the following command:

firewall-cmd --permanent --add-port=25/tcp
firewall-cmd --reload

You can test it by sending an email to a valid email address from your server’s command line using the mail command, for example:

sudo dnf install mailx

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

Installing Postfix on Ubuntu and Debian

Open a terminal or login to your server via SSH as a root user.

Update your system packages by running the following command:

apt-get update

Install Postfix using the following command:

apt-get install postfix

Start the Postfix service using the following command:

systemctl start postfix

To make sure Postfix starts automatically after a server reboot, run the following command:

systemctl enable postfix

By default, Postfix listens on port 25 for incoming mail. If you’re running a firewall on your server, make sure to open port 25 by running the following command:

ufw allow 25/tcp

sudo apt-get install mailutils

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