Setting up a CNAME record for any of the domain addresses or subdomains that you have within a hosting account will permit you to redirect it to a different domain/subdomain. The forwarded Internet domain will lose all of its records - A, MX etc, and will take the records of the domain address it's being forwarded to. In this light, you simply can't set up a CNAME record to forward your domain name to a third-party company and keep 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 never a number as it's frequently confused with the A record of the Internet domain being redirected. One of the major uses of a CNAME record is to point a domain you own through one provider to the servers of some other company in case you have set up a website with the latter. By doing this, the Internet site will appear under your own domain address, not under some subdomain provided by the third-party company.