Setting up a CNAME record for each of the domain names or subdomains that you've got in a hosting account will enable you to redirect it to a different domain/subdomain. The forwarded domain address will lose all its records - A, MX etc, and will take the records of the domain it is being directed to. In this light, you can't set up a CNAME record to point your domain name to a third-party provider and maintain a working e-mail service with the first provider. It is also essential to know that a CNAME record is always a string of words and not a number as it's commonly confused with the A record of the domain address being redirected. One of the major uses of a CNAME record is to point a domain address which you own through one company to the servers of another provider if you have created a website with the latter. In this way, the Internet site will appear under your own domain, not under some subdomain provided by the third-party company.