How to install Postfix on Ubuntu

Want to send emails from your applications? Postfix is a reliable and secure mail transfer agent (MTA). This guide sets up a basic, secure outbound mail server.

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Requirements

• Linux VPS (Ubuntu 20.04+ recommended)

• Domain name (DNS access required)

• Open ports: 25, 587

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Step 1: Update system

sudo apt update

(Optional)

sudo apt upgrade -y

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Step 2: Install Postfix

sudo apt install postfix mailutils -y

Choose:

• Internet Site

• Domain: example.com

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Step 3: Basic configuration

sudo nano /etc/postfix/main.cf

Minimal config:

myhostname = mail.example.com
mydomain = example.com
myorigin = $mydomain

inet_interfaces = all
inet_protocols = ipv4

mydestination = $myhostname, localhost.$mydomain, localhost

mynetworks = 127.0.0.0/8
relay_domains =

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Step 4: Start Postfix

sudo systemctl restart postfix
sudo systemctl enable postfix

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Step 5: Test sending

echo "Test email" | mail -s "Test" [e-mail]

Check logs:

sudo tail -f /var/log/mail.log

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Step 6: DNS setup (IMPORTANT)

Add:

• MX → mail.example.com

• A → mail.example.com → your IP

SPF:

v=spf1 mx ip4:YOUR_IP ~all

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Step 7: Enable authentication (basic)

sudo apt install libsasl2-modules sasl2-bin -y

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Common issues

Emails go to spam

• Missing SPF

• No reverse DNS (PTR)

• No DKIM

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Done 🎉

Postfix is ready to send emails.