public function addBccRecipient($address, $variables = null)
{
if ($this->counters['recipients']['bcc'] > Api::RECIPIENT_COUNT_LIMIT) {
throw new TooManyParameters(ExceptionMessages::TOO_MANY_PARAMETERS_RECIPIENT);
}
$this->addRecipient('bcc', $address, $variables);
return end($this->message['bcc']);
}