Creating a CNAME record for any of the domains or subdomains that you have in the 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 etc, and will take the records of the domain name it is being pointed to. In this light, you simply can't create a CNAME record to forward your domain name to a third-party company and keep a working email service with the first provider. It is also important to note that a CNAME record is always a string of words and never a number as it is often confused with the A record of the domain being forwarded. One of the primary uses of a CNAME record is to forward a domain name you own through one provider to the servers of another company assuming you have created a website with the latter. In this way, the site will appear under your own domain address, not under some subdomain provided by the third-party provider.