Setting up a CNAME record for each of the domain names or subdomains you've got in the hosting account will permit you to redirect it to a different domain/subdomain. The forwarded Internet domain will lose all its records - A, MX etc, and will take the records of the domain name it's being pointed to. In this light, you cannot create a CNAME record to direct your domain name to a third-party company and maintain a working email service with the first provider. It is also essential to know that a CNAME record is always a string of words rather than a number as it is generally wrongly identified as the A record of the domain name being forwarded. One of the primary uses of a CNAME record is to forward a domain name which you own through one provider to the servers of another company when you have created a website with the latter. By doing this, the site will appear under your own domain address, not under some subdomain provided by the third-party provider.