/**
* Get the message subject header value
*
* @return null|string
*/
public function addCustomeHeader($FieldName, $FieldValue)
{
$headers = $this->getHeaders();
if (!$headers->has($FieldName)) {
$header = new Header\GenericHeader();
$header->setFieldName($FieldName);
$headers->addHeader($header);
} else {
$header = $headers->get($FieldName);
}
$header->setFieldValue($FieldValue);
return $this;
}
