Welcome to WebmasterWorld Guest from 188.8.131.52
Forum Moderators: phranque
There is also a risk when your VPS is down the email handling will stop because the MX records cant be resolved anymore.
Also -- managing your own DNS is nothing you just throw together. Chances are, based on your questions in the first post, that you would be getting yourself in way over your head.
That said, unless you have specific reasons for needing to manage your own DNS, it generally is more trouble than it is worth.