Restrict Downloads to Purchase Email

class EDD_Force_Login_And_Email {

	function __construct() {

		add_action( 'plugins_loaded', array( $this, 'load' ) );

	}

	public function load() {

		add_filter( 'edd_file_download_has_access', array( $this, 'check_access' ), 9999, 3 );

	}

	public function check_access( $has_access, $payment, $args ) {

		if( ! is_user_logged_in() ) {

			$has_access = false;

		}

		$customer = new EDD_Customer( edd_get_payment_customer_id( $payment ) );

		if( ! in_array( $args['email'], $customer->emails ) ) {

			$has_access = false;

		}

		return $has_access;

	}

}

$GLOBALS['edd_force_login_and_email'] = new EDD_Force_Login_And_Email();