public function GetMailMIME()
{
$result = '';
switch ($this->message_type) {
case 'plain':
$result .= $this->HeaderLine('Content-Transfer-Encoding', $this->Encoding);
$result .= sprintf("Content-Type: %s; charset=\"%s\"", $this->ContentType, $this->CharSet);
break;
case 'attachments':
/* fall through */
/* fall through */
case 'alt_attachments':
if ($this->InlineImageExists()) {
$result .= sprintf("Content-Type: %s;%s\ttype=\"text/html\";%s\tboundary=\"%s\"%s", 'multipart/related', $this->LE, $this->LE, $this->boundary[1], $this->LE);
} else {
$result .= $this->HeaderLine('Content-Type', 'multipart/mixed;');
$result .= $this->TextLine("\tboundary=\"" . $this->boundary[1] . '"');
}
break;
case 'alt':
$result .= $this->HeaderLine('Content-Type', 'multipart/alternative;');
$result .= $this->TextLine("\tboundary=\"" . $this->boundary[1] . '"');
break;
}
if ($this->Mailer != 'mail') {
$result .= $this->LE . $this->LE;
}
return $result;
}