So, *everyone* needs a simple form to send emails, via PHP, but we also need a protection agains bots/spammers.
This is code that i’v grabbed from codeforgeek and improved since the original had a few errors that made it impossible to run/work/send email.

It uses Google reCaptcha and you need to register you site/domain on it and grab the site key and the secret key.

The form already has twitter bootstrap classes… but you can remove them! 🙂

The form.php – at the begin

<?php
	$to      = '[email protected]';
	$subject = 'Support Message';

	// keys from Google reCaptcha https://www.google.com/recaptcha/admin
	$sitekey = 'recaptcha_site_key';
	$secretkey = 'recaptcha_secret_key';

	$alert = '';
	if ($_SERVER['REQUEST_METHOD'] == 'POST')
	{
		$email;$message;$captcha;
		if(isset($_POST['email']))
        			$email=$_POST['email'];
		        if(isset($_POST['message']))
        			$message=$_POST['message'];
			if(isset($_POST['g-recaptcha-response']))
        		$captcha=$_POST['g-recaptcha-response'];

	        	if(!$captcha)
        		$alert = '<div class="alert alert-warning" role="alert">Please wait until the captcha protection give you a check mark.</div>';

        	$response=json_decode(file_get_contents("https://www.google.com/recaptcha/api/siteverify?secret='.$secretkey.'&response=".$captcha."&remoteip=".$_SERVER['REMOTE_ADDR']));

		if($response->success==false)
		{
			/* lets set the error message for the alert... */
			if ($alert=='')
				$alert = '<div class="alert alert-danger" role="alert">Some how you have been detected has a spammer.</div>';
        	}
		else
		{
			/* the email to you */
			$headers = 'From: '.$to.'' . "\r\n" .
                	'Reply-To: '.$email.'' . "\r\n" .
                	'X-Mailer: PHP/' . phpversion();
            		mail($to, $subject, $message, $headers);
			/* the copy of the email to the *client* */
			$headers = 'From: '.$email.'' . "\r\n" .
				'Reply-To: '.$to.'' . "\r\n" .
				'X-Mailer: PHP/' . phpversion();
			mail($email, 'COPY - '. $subject, $message, $headers);
			/* lets set the success message for the alert... */
			$alert = '<div class="alert alert-success" role="alert">Your email has been sent.</div>';
        	}
	}
?>

The html form

<?=$alert?>
<form id="comment_form" action="" method="post">
	<input name="email" type="email" placeholder="Type your email" size="40" class="form-control" value="<?=@$email?>" ><br><br>
	<textarea name="message" rows="8" cols="39" class="form-control"  placeholder="Your message to us..." ><?=@$message?></textarea><br>
	<div class="g-recaptcha" data-sitekey="<?=$sitekey?>"></div><br>
	<input type="submit" name="submit" value="Send message" class="btn btn-default"><br>
</form>

Some where at the bottom/footer…

<script src='https://www.google.com/recaptcha/api.js'></script>

Hope it helps anyone! 🙂