Mail::isAttachmentImage

private function isAttachmentImage(&$attachment, $checkRelated = false)
{
	if (empty($attachment['CONTENT_TYPE']))
	{
		return false;
	}

	if ($checkRelated && empty($attachment['RELATED']))
	{
		return false;
	}

	if (mb_strpos($attachment['CONTENT_TYPE'], 'image/') === 0)
	{
		return true;
	}

	return false;
}