и это то, что я сделал, и получаю ошибку,
$mailChimp = new MailChimp('xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx');
$mailChimp->from('xxxxxxxxxxxxxxxxxxxxxx');
$mailChimp->reply_to('xxxxxxxxxxxxxxxxxxxxxxxx');
$mailChimp->to(xxxxxxxxxxxxxxxxxxxx);
$mailChimp->subject('xxxxxxxxxxxxx');
$mailChimp->message($message);
$mailChimp->set_header('MIME-Version', '1.0; charset=utf-8');
$mailChimp->set_header('Content-type', 'text/html');
$mailChimp->mailtype('html');