Looking at the
whois for kky.co.id the DNS is hosted at the ISP
DNET.NET.ID.
There are millions of phishing ads online these days, you should educate your users on ensuring the domain name on any communications is indeed your own, and that you'd never request their passwords via EMail. Additionally, you might point out that any forum generated emails will be sent through the forum software and they should look like the forum (posting an example from a PT notification would probably work really well).