Creating a CNAME record for any one of the domains or subdomains you have in the hosting account allows you to forward it to a different domain/subdomain. The forwarded domain name will lose all of its records - A, MX and so on, and will take the records of the domain it's being forwarded to. In this light, you can't create a CNAME record to redirect your domain name to a third-party company and maintain a functional email service with the first provider. Additionally, it is essential to know that a CNAME record is always a string of words and never a number as it's commonly wrongly identified as the A record of the domain name being forwarded. One of the primary uses of a CNAME record is to direct a domain address that you own through one provider to the servers of another provider if you have created an Internet site with the latter. In this way, the site will appear under your own domain, not under some subdomain provided by the third-party provider.