How to Set Up an Email Server on openSUSE

Email servers are essential for managing and sending emails efficiently. openSUSE, a powerful and versatile Linux distribution, is an excellent choice for setting up an email server. In this comprehensive guide, we’ll walk you through the entire process of how to set up an email server on openSUSE, from installing the necessary software to configuring email services.

Prerequisites

Before you start, make sure you have the following:

1. A fully updated openSUSE system.
2. A registered domain name.
3. Root access or a user account with sudo privileges.

How to Set Up an Email Server on openSUSE

Install and Configure Postfix

Postfix is a popular open-source mail transfer agent (MTA) that routes and delivers email messages. To install Postfix on openSUSE, run the following command:

sudo zypper install postfix

After installing Postfix, configure the main settings by editing /etc/postfix/main.cf. Use your preferred text editor, such as Vim or Nano.

sudo vim /etc/postfix/main.cf

Modify the following settings with your domain name:

myhostname = mail.yourdomain.com
mydomain = yourdomain.com
myorigin = $mydomain
inet_interfaces = all
inet_protocols = ipv4

Once you’ve made the changes, restart Postfix:

sudo systemctl restart postfix

Install and Configure Dovecot

Dovecot is an open-source IMAP and POP3 email server that allows users to access their email from multiple devices. Install Dovecot using the following command:

sudo zypper install dovecot

After the installation, configure Dovecot by editing /etc/dovecot/dovecot.conf. Use your favourite text editors, like Vim or Nano.

sudo vim /etc/dovecot/dovecot.conf

Uncomment the following lines:

protocols = imap pop3
listen = *

Next, configure the mail location in /etc/dovecot/conf.d/10-mail.conf:

sudo vim /etc/dovecot/conf.d/10-mail.conf

Add or modify the following line:

mail_location = mbox:~/mail:INBOX=/var/mail/%u

Now, configure the authentication mechanism in /etc/dovecot/conf.d/10-auth.conf:

sudo vim /etc/dovecot/conf.d/10-auth.conf

Uncomment and modify the following lines:

disable_plaintext_auth = no
auth_mechanisms = plain login

Finally, restart Dovecot:

sudo systemctl restart dovecot

Configure Firewall and Test Email Server

Open the required ports in your firewall to allow incoming and outgoing email traffic:

sudo firewall-cmd --add-service=smtp --permanent
sudo firewall-cmd --add-service=pop3 --permanent
sudo firewall-cmd --add-service=imap --permanent
sudo firewall-cmd --reload

To test your email server, install the mailx package:

sudo zypper install mailx

Send a test email to a local user:

echo "This is a test email" | mail -s "Test Email" [email protected]

Check the user’s mailbox for the test email:

sudo su - user
mail

If the test email is present in the user’s mailbox, your email server is functioning correctly.

Set Up SSL/TLS for Secure Email Communication

To secure your email server, you need to set up SSL/TLS encryption. First, obtain an SSL certificate for your domain. You can use Let’s Encrypt to obtain a free SSL certificate.

Install the certbot package:

sudo zypper install certbot

Now, run Certbot to obtain an SSL certificate:

sudo certbot certonly --standalone -d mail.yourdomain.com

After obtaining the SSL certificate, configure Postfix to use it. Edit /etc/postfix/main.cf:

sudo vim /etc/postfix/main.cf

Add or modify the following lines:

smtpd_use_tls = yes
smtpd_tls_cert_file = /etc/letsencrypt/live/mail.yourdomain.com/fullchain.pem
smtpd_tls_key_file = /etc/letsencrypt/live/mail.yourdomain.com/privkey.pem

Restart Postfix:

sudo systemctl restart postfix

Next, configure Dovecot to use the SSL certificate. Edit /etc/dovecot/conf.d/10-ssl.conf:

sudo vim /etc/dovecot/conf.d/10-ssl.conf

Modify the following lines:

ssl = required
ssl_cert = </etc/letsencrypt/live/mail.yourdomain.com/fullchain.pem
ssl_key = </etc/letsencrypt/live/mail.yourdomain.com/privkey.pem

Restart Dovecot:

sudo systemctl restart dovecot

Configure DNS Records

Lastly, configure the DNS records for your domain. Add the following DNS records:

1. A record: Point the mail.yourdomain.com subdomain to your server’s IP address.
2. MX record: Set the priority to 10 and point it to mail.yourdomain.com.

Please consult your domain registrar or DNS hosting provider for assistance in configuring DNS records.

Conclusion

Congratulations! You have successfully set up an email server on openSUSE using Postfix and Dovecot. Now you can efficiently manage and send emails from your domain. Don’t forget to explore other useful tutorials on LinuxBoost, such as how to install Ruby on openSUSE or how to set up an OpenVPN server on openSUSE.