<?php require 'vendor/autoload.php'; define('MAILGUN_KEY', 'key-88299b6a103ceb867b4d034c68444c5e'); define('MAILGUN_PUBKEY', 'pubkey-c10823b85a2e38cb36963cba32430dd2'); define('MAILGUN_DOMAIN', 'sandboxfa8dfb14a3254a60af9d8e3fe458b496.mailgun.org'); define('MAILGUN_LIST', '*****@*****.**'); define('MAILGUN_SECRET', 'mynameisjagga'); $mailgun = new Mailgun\Mailgun(MAILGUN_KEY); $mailgunValidate = new Mailgun\Mailgun(MAILGUN_PUBKEY); $mailgunOptIn = $mailgun->OptInHandler();