Step-by-Step Guide to Setting Up a Mail Server on Linux

Setting up a mail server on Linux allows you to send and receive emails securely without relying on third-party providers. In this guide, we’ll configure Postfix, Dovecot, and Roundcube to create a self-hosted email system.

1. Prerequisites: What You Need Before Setup

• ✅ A Linux server (Ubuntu, Debian, or CentOS).
• ✅ A fully qualified domain name (FQDN) (e.g., mail.yourdomain.com).
• ✅ Open firewall ports: 25 (SMTP), 143/993 (IMAP), and 110/995 (POP3).

⚡ Update Your Server

    sudo apt update && sudo apt upgrade -y
    

2. Set Up a Hostname & DNS Records

✅ Step 1: Set a Hostname (FQDN)

    sudo hostnamectl set-hostname mail.yourdomain.com
    

✅ Step 2: Configure DNS Records

Configure the following DNS records:

3. Install & Configure Postfix (SMTP Server)

✅ Step 1: Install Postfix

    sudo apt install postfix -y
    

✅ Step 2: Configure Postfix

    sudo nano /etc/postfix/main.cf
    

Update the file with:

    myhostname = mail.yourdomain.com
    mydomain = yourdomain.com
    myorigin = $mydomain
    inet_interfaces = all
    home_mailbox = Maildir/
    

✅ Step 3: Restart Postfix

    sudo systemctl restart postfix
    

4. Install & Configure Dovecot (IMAP/POP3)

✅ Step 1: Install Dovecot

    sudo apt install dovecot-core dovecot-imapd dovecot-pop3d -y
    

✅ Step 2: Configure Dovecot

    sudo nano /etc/dovecot/dovecot.conf
    

Ensure the following settings are enabled:

    protocols = imap pop3 lmtp
    mail_location = maildir:~/Maildir
    

✅ Step 3: Restart Dovecot

    sudo systemctl restart dovecot
    

5. Secure the Mail Server with SSL/TLS

✅ Step 1: Install Let’s Encrypt SSL

    sudo apt install certbot -y
    

✅ Step 2: Obtain a Free SSL Certificate

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

6. Install Roundcube Webmail

✅ Step 1: Install Apache & PHP

    sudo apt install apache2 php php-mysql php-xml php-mbstring -y
    

✅ Step 2: Install Roundcube

    sudo apt install roundcube -y
    

Access Roundcube at:

    http://mail.yourdomain.com/roundcube
    

Final Thoughts: Your Linux Mail Server is Ready!

• ✅ Configured Postfix for sending emails (SMTP).
• ✅ Set up Dovecot for receiving emails (IMAP/POP3).
• ✅ Secured email transmission with SSL/TLS.
• ✅ Installed Roundcube for webmail access.

Want a fully functional, secure mail server? Implement SPF, DKIM, and DMARC to prevent spam and spoofing!