PHP and mailgun configuration

mail.php

<?php
	define('MAILGUN_URL', 'https://api.mailgun.net/v3/YOUR_URL');
	define('MAILGUN_KEY', 'MAILGUN_KEY'); 

	$mail = $_POST;
	$name = $mail['name'];
	$from = $mail['email'];

	if(empty($from) || empty($name)) {
		print('false');
		return false;
	}
	
	$message = '
	Compañía: '.$mail['company'].'
	Nombre de contacto: '.$name.'
	Ciudad: '.$mail['city'].'
	Teléfono: '.$mail['phone'].'
	
	'.$mail['message'];
	$to = "gmotzespina@icloud.com";
	$subject = "Contacto de Powerjet";
	
	$array_data = array(
		'from'=> 'Visitante de Powerjet' .'<'.$from.'>',
		'to'=> $to,
		'subject'=> $subject,
		'text'=> $message,
		'o:tracking'=>'yes',
		'o:tracking-clicks'=>'yes',
		'o:tracking-opens'=>'yes'
    );
    
    $session = curl_init(MAILGUN_URL.'/messages');
    curl_setopt($session, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
  	curl_setopt($session, CURLOPT_USERPWD, 'api:'.MAILGUN_KEY);
    curl_setopt($session, CURLOPT_POST, true);
    curl_setopt($session, CURLOPT_POSTFIELDS, $array_data);
    curl_setopt($session, CURLOPT_HEADER, false);
    curl_setopt($session, CURLOPT_ENCODING, 'UTF-8');
    curl_setopt($session, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($session, CURLOPT_SSL_VERIFYPEER, false);
    $response = curl_exec($session);
    curl_close($session);
    print($response);
?>