Point old Server to new Server?

Hi All,

I have a new server. I have used WHM to copy all the accounts from the old Server over to new Server. So far so good.
The problem is, I want to make sure that my clients are accessing the new server and not the old server while I update the new NS on the individual domains. These are co.za domains and will take about 24 hours to resolve.

Is there a way I can point or update the Old Server in a way that any atempt to access it i.e mail.CLIENTDOMAIN.co.za automatically goes to the New Server. I would want to make sure that new mail been emailed to my clients is going to the mail boxes on the new server and not the old.

Thank you.

 

Thanks. But do I have to do it for all the individual accounts or is there a way to do all the accounts at once?