MailBlockBase::update

static function update($blockName, $html)
{
	$result = false;
	$fullPathOfFile = BitrixMainLoader::getLocal(static::LOCAL_DIR_BLOCK . bx_basename($blockName) . '.html');
	if ($fullPathOfFile)
		$result = File::putFileContents($fullPathOfFile, $html);

	return $result;
}