Setting up a CNAME record for any of the domain names or subdomains you have within a hosting account will enable you to forward it to a different domain/subdomain. The forwarded domain address will lose all its records - A, MX and so on, and will take the records of the domain it is being pointed to. In this light, you can't create a CNAME record to redirect your domain name to a third-party company and keep a functional email service with the first provider. Additionally, it is important to note that a CNAME record is always a string of words rather than a number as it's regularly confused with the A record of the Internet domain being forwarded. One of the primary uses of a CNAME record is to forward a domain name you own through one company to the servers of another company when you have created an Internet site with the latter. By doing this, the site will appear under your own domain, not under some subdomain provided by the third-party company.