Creating a CNAME record for any one of the domains or subdomains you have in a hosting account will permit you to redirect it to a different domain/subdomain. The forwarded Internet domain will lose all its records - A, MX and so forth, and will take the records of the domain name it's being directed to. In this light, you simply can't create a CNAME record to redirect your domain name to a third-party company and maintain a functional email service with the first hosting provider. It's also important to note that a CNAME record is always a string of words and not a number because 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 direct a domain that you own through one provider to the servers of some other company if you have set up a site with the latter. This way, the Internet site will appear under your own domain name, not under some subdomain provided by the third-party company.