Mailgun SMTP Settings (2026)

// Using PHPMailer: composer require phpmailer/phpmailer
use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\SMTP;
use PHPMailer\PHPMailer\Exception;

require 'vendor/autoload.php';

$mail = new PHPMailer(true);

try {
    // Mailgun SMTP settings
    // Use smtp.eu.mailgun.org for EU region
    $mail->isSMTP();
    $mail->Host       = 'smtp.mailgun.org';
    $mail->SMTPAuth   = true;
    $mail->Username   = getenv('MAILGUN_SMTP_USER');
    $mail->Password   = getenv('MAILGUN_SMTP_PASSWORD');
    $mail->SMTPSecure = PHPMailer::ENCRYPTION_STARTTLS;
    $mail->Port       = 587;

    // Sender & recipient
    $mail->setFrom('sender@mg.yourdomain.com', 'Your Name');
    $mail->addAddress('recipient@example.com');

    // Optional: Mailgun-specific headers
    $mail->addCustomHeader('X-Mailgun-Tag', 'welcome-email');
    $mail->addCustomHeader('X-Mailgun-Track-Opens', 'yes');

    // Content
    $mail->isHTML(true);
    $mail->Subject = 'Hello from Mailgun';
    $mail->Body    = '<h1>Welcome!</h1><p>This is a test email.</p>';
    $mail->AltBody = 'Welcome! This is a test email.';

    $mail->send();
    echo 'Email sent successfully!';
} catch (Exception $e) {
    echo "Error: {$mail->ErrorInfo}";
}

// npm install nodemailer dotenv
const nodemailer = require('nodemailer');
require('dotenv').config();

// Create transporter with Mailgun SMTP
// Use smtp.eu.mailgun.org for EU region
const transporter = nodemailer.createTransport({
    host: 'smtp.mailgun.org',
    port: 587,
    secure: false,
    auth: {
        user: process.env.MAILGUN_SMTP_USER,
        pass: process.env.MAILGUN_SMTP_PASSWORD
    }
});

async function sendEmail() {
    try {
        const info = await transporter.sendMail({
            from: '"Your Name" <sender@mg.yourdomain.com>',
            to: 'recipient@example.com',
            subject: 'Hello from Mailgun',
            html: '<h1>Welcome!</h1><p>This is a test email.</p>',
            // Optional: Mailgun-specific headers
            headers: {
                'X-Mailgun-Tag': 'welcome-email',
                'X-Mailgun-Track-Opens': 'yes',
                'X-Mailgun-Track-Clicks': 'yes'
            }
        });

        console.log('Message sent: %s', info.messageId);
    } catch (error) {
        console.error('Error:', error);
    }
}

sendEmail();

# gem install mail
require 'mail'

# Configure Mailgun SMTP
# Use smtp.eu.mailgun.org for EU region
Mail.defaults do
  delivery_method :smtp, {
    address:              'smtp.mailgun.org',
    port:                 587,
    user_name:            ENV['MAILGUN_SMTP_USER'],
    password:             ENV['MAILGUN_SMTP_PASSWORD'],
    authentication:       :plain,
    enable_starttls_auto: true
  }
end

# Send email
mail = Mail.new do
  from    'sender@mg.yourdomain.com'
  to      'recipient@example.com'
  subject 'Hello from Mailgun'

  # Mailgun-specific headers
  header['X-Mailgun-Tag'] = 'welcome-email'
  header['X-Mailgun-Track-Opens'] = 'yes'

  html_part do
    content_type 'text/html; charset=UTF-8'
    body '<h1>Welcome!</h1><p>This is a test email.</p>'
  end
end

mail.deliver!
puts 'Email sent successfully!'

// go get gopkg.in/gomail.v2
package main

import (
    "os"
    "gopkg.in/gomail.v2"
)

func main() {
    // Mailgun SMTP configuration
    // Use smtp.eu.mailgun.org for EU region
    smtpServer := "smtp.mailgun.org"
    smtpPort := 587
    smtpUser := os.Getenv("MAILGUN_SMTP_USER")
    smtpPass := os.Getenv("MAILGUN_SMTP_PASSWORD")

    // Create message
    m := gomail.NewMessage()
    m.SetHeader("From", "sender@mg.yourdomain.com")
    m.SetHeader("To", "recipient@example.com")
    m.SetHeader("Subject", "Hello from Mailgun")
    m.SetBody("text/html", "<h1>Welcome!</h1><p>This is a test email.</p>")

    // Optional: Mailgun-specific headers
    m.SetHeader("X-Mailgun-Tag", "welcome-email")
    m.SetHeader("X-Mailgun-Track-Opens", "yes")

    // Send
    d := gomail.NewDialer(smtpServer, smtpPort, smtpUser, smtpPass)

    if err := d.DialAndSend(m); err != nil {
        panic(err)
    }
}