I think you got it wrong. NetSol is where I bought my domain names. My account lets me log in and set the DNS names myself. And that's all NetSol is for. I don't host with them, I don't buy an e-mail account.

Once I buy the domain, I can host it anywhere. So I buy server space by the year and I get a Unique IP, unlimited mail accounts, I can alias them, redirect, forward and set up autoresponders if I want. And I get a control panel to manage all that, including files, permissions, all that stuff.

It didn't cost me a nickel to change my DNS servers at NetSol. I don't know why it would.