Setting up a CNAME record for any of the domains or subdomains you've got within a hosting account will permit you to forward it to a different domain/subdomain. The forwarded domain will lose all its records - A, MX etc, and will take the records of the domain name it is being pointed to. In this light, you cannot create a CNAME record to direct your domain to a third-party company and maintain a working e-mail service with the first hosting provider. It is also essential to know that a CNAME record is always a string of words rather than a number as it's frequently wrongly identified as the A record of the domain name being redirected. One of the primary uses of a CNAME record is to forward a domain address that you own through one provider to the servers of another provider assuming you have set up an Internet site with the latter. This way, the Internet site will appear under your own domain name, not under some subdomain provided by the third-party provider.