@LuDo8 / @Maniac_
Thanks guys for the advice.
I was able to setup my VPS with nameserver & mail server with web mail (squirrelmail). but I guess @Maniac_ is right, there has not been much load on my VPS yet and I am already using more than 60% of the memory allocation.
I think, I would just remove these applications and run a basic web server. I will just use a free nameservers and an email.