Creating a CNAME record for any of the domains or subdomains that you have within a hosting account will allow you to redirect it to a different domain/subdomain. The forwarded domain will lose all its records - A, MX and so on, and will take the records of the domain it's being forwarded to. In this light, you simply can't set up a CNAME record to point your domain name to a third-party company and retain a working e-mail service with the first provider. It's also essential to know that a CNAME record is always a string of words rather than a number as it's commonly mistaken for the A record of the domain name being redirected. One of the primary uses of a CNAME record is to point a domain which you own through one provider to the servers of some other company assuming you have set up an Internet site with the latter. In this way, the site will appear under your own domain, not under some subdomain provided by the third-party provider.