Creating a CNAME record for any of the domain names or subdomains that you have in the hosting account will enable you to redirect it to a different domain/subdomain. The forwarded domain address will lose all its records - A, MX and so forth, and will take the records of the domain name it is being directed to. In this light, you can't set up a CNAME record to direct your domain name to a third-party company and retain a working email service with the first hosting provider. Also, it is essential to know that a CNAME record is always a string of words rather than a number as it's generally wrongly identified as the A record of the domain name being redirected. One of the primary uses of a CNAME record is to point a domain address you own through one provider to the servers of some other company in case you have created a website with the latter. By doing this, the website will appear under your own domain name, not under some subdomain provided by the third-party company.