Setting up a CNAME record for any of the domain names or subdomains you have within a hosting account allows you to forward it to a different domain/subdomain. The forwarded Internet domain will lose all its records - A, MX and so on, and will take the records of the Internet domain it's being forwarded to. In this light, you cannot create a CNAME record to direct your domain to a third-party company and keep a functional e-mail service with the first hosting provider. It is also essential to know that a CNAME record is always a string of words and never a number as it is often mistaken for the A record of the Internet domain being forwarded. One of the primary uses of a CNAME record is to direct a domain address you own through one company to the servers of another provider when you have created a site with the latter. By doing this, the Internet site will appear under your own domain, not under some subdomain provided by the third-party provider.