protected function obfuscate($mail)
    {
        return preg_replace_callback('/^([^@]+)(.*)$/', function ($matches) {
            $lenght = floor(strlen($matches[1]) / 2);
            $name = substr($matches[1], 0, $lenght) . str_repeat('*', $lenght);

            return $name . $matches[2];
        }, $mail);
    }