If you have a new domain name, you must change the name servers so they point to myvhosting.com.
Name server changes usually take 24 to 72 hours to start working. This phenomenon is known as propagation. Because of propagation, not all visitors will follow your new name servers to your new hosting account; some visitors will continue to follow your old name servers to your old hosting account.
How quickly visitors follow the new name servers depends on their physical location, internet service provider, and some luck; it is not something HostGator has control over. Once propagation is over, your site will be appearing on our server and your email will be fully functional.
There is no positive way to tell when propagation has completed. During the first 72 hours, even if you see your site on the new server, your next door neighbor might see the site on the old server.