Setting up a CNAME record for any one of the domains or subdomains that you've got in the hosting account allows you to direct 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 Internet domain it's being redirected to. In this light, you simply can't create a CNAME record to direct your domain name to a third-party company and retain a functional e-mail service with the first provider. Also, it is essential to know that a CNAME record is always a string of words and never a number because it is often confused with the A record of the domain being forwarded. One of the main uses of a CNAME record is to point a domain address that you own through one provider to the servers of some other provider when you have created an Internet site with the latter. That way, the website will appear under your own domain address, not under some subdomain provided by the third-party company.