Setting up a CNAME record for any one of the domain names or subdomains that you've got in a hosting account will allow you to forward it to a different domain/subdomain. The forwarded Internet domain will lose all of its records - A, MX and so forth, and will take the records of the domain address it's being pointed to. In this light, you can't create a CNAME record to forward your domain name to a third-party company and retain a working e-mail service with the first hosting provider. Additionally, it is very important to know that a CNAME record is always a string of words and not a number as it is frequently mistaken for the A record of the domain being forwarded. One of the main uses of a CNAME record is to direct a domain that you own through one company to the servers of another provider if you have set up 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.