If you already own one or more domain names that you want to use with your XSite, you can easily attach them to your XSite using the domain manager in your site — for free. To attach a domain that you already own to your XSite:
Once you make the necessary changes to your domain, your XSite will take care of the rest. Keep in mind that any changes you make to your domain settings may take between 24 and 48 hours to complete as those changes have to make their way across the entire Internet. This "down time" cannot be avoided either through XSite OR through any other website provider, so be sure to account for a website and email outage for any websites or email attached to that web address.