Creating a CNAME record for each of the domain names or subdomains that you've got within a hosting account will allow you to point it to a different domain/subdomain. The forwarded domain address will lose all of its records - A, MX and so forth, and will take the records of the domain address it is being pointed to. In this light, you simply can't create a CNAME record to point your domain to a third-party company and keep a functional email service with the first hosting company. It's also very important to know that a CNAME record is always a string of words rather than a number as it is often mistaken for the A record of the domain being redirected. One of the main uses of a CNAME record is to forward a domain name that you own through one company to the servers of some other company in case you have set up an Internet site with the latter. In this way, the Internet site will appear under your own domain address, not under some subdomain provided by the third-party provider.