Setting up a CNAME record for each of the domains or subdomains that you've got in a hosting account will permit you to point 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's being forwarded to. In this light, you simply can't set up a CNAME record to redirect your domain name to a third-party company and retain a functional email service with the first hosting provider. Also, it is essential to know that a CNAME record is always a string of words and not a number as it is often confused with the A record of the domain being redirected. One of the major uses of a CNAME record is to point a domain address which you own through one company to the servers of another company when you have set up an Internet site with the latter. In this way, the website will appear under your own domain address, not under some subdomain provided by the third-party company.