Responsive Contact Form with Google reCAPTCHA + SMTP Mailer

Create secure, professional contact forms in minutes. 

This lightweight PHP script features Google reCAPTCHA v3 integration, built-in SMTP mail sending, spam protection, and no external libraries needed. 

Fully responsive and mobile-ready, it's perfect for modern websites that need reliable contact functionality with minimal setup. 

Includes JavaScript and PHP validation, honeypot security, and user confirmation emails - all in one clean, customizable package.

🚀 How It Works

• ➤ User fills out the form and submits
• ➤ Client-side JavaScript validates inputs
• ➤ Google reCAPTCHA is verified
• ➤ Honeypot spam trap is checked
• ➤ Admin receives an email
• ➤ User receives a confirmation email

✨ Features

• ✅ Fully responsive layout.
  Designed to work seamlessly on all screen sizes—desktops, tablets, and mobile devices.
• ✅ Google reCAPTCHA v3 integration.
  Helps protect your form from bots and spam without user interaction, using invisible background validation.
• ✅ Honeypot spam protection.
  A simple but effective hidden field technique that blocks most automated spam bots.
• ✅ JavaScript + PHP validation.
  Ensures that the form is validated both on the client side (for UX) and server side (for security).
• ✅ Built-in SMTP mailer using.
  Sends messages securely via any SMTP server without relying on third-party libraries.
• ✅ Confirmation email to the user.
  Automatically sends a confirmation message to users, enhancing trust and communication.
• ✅ No PHPMailer or external libraries needed.
  Lightweight and dependency-free, making it easy to maintain and deploy.

🔧 Requirements

• PHP 7.2+ runtime.
• OpenSSL extension enabled.
• fsockopen() must be enabled on your server. (contact us for additional server support).
• A valid SMTP account. (e.g., Gmail, Outlook, Zoho, etc).

💻 Installation

1. ➤ Upload the files to your PHP web server
2. ✎ Open send.php and edit the configuration section:

// === CONFIGURATION ===
$admin_email       = '[email protected]';
$from_email        = '[email protected]';
$from_name_prefix  = 'Your Site Name';
// reCAPTCHA keys (get from https://www.google.com/recaptcha/admin)
$recaptcha_sitekey = 'your-site-key';
$recaptcha_secret  = 'your-secret-key';
// SMTP credentials
$smtp_host = 'smtp.yourhost.com';
$smtp_port = 587;
$smtp_user = '[email protected]';
$smtp_pass = 'your-smtp-password';
// === END CONFIGURATION ===
    

1. ✎ Edit index.php and update this button to use your site key:

<button
  class="g-recaptcha"
  data-sitekey="your-site-key"
  data-callback="onSubmit"
  data-action="submit">
  Send Message
</button>