Creating a CNAME record for each of the domains or subdomains you've got within a hosting account will enable you to redirect it to a different domain/subdomain. The forwarded domain will lose all of its records - A, MX and so on, and will take the records of the Internet domain it is being redirected to. In this light, you simply can't create a CNAME record to forward your domain to a third-party company and maintain a functional e-mail service with the first hosting company. Additionally, it is essential to know that a CNAME record is always a string of words rather than a number because it is generally wrongly identified as the A record of the domain name being redirected. One of the major uses of a CNAME record is to direct a domain name that you own through one company to the servers of another company in case you have set up a site with the latter. That way, the Internet site will appear under your own domain name, not under some subdomain provided by the third-party provider.