Setting up a CNAME record for each of the domains or subdomains that you've got within a hosting account will allow you to redirect it to a different domain/subdomain. The forwarded domain address will lose all of its records - A, MX and so forth, and will take the records of the domain name it's being pointed to. In this light, you cannot create a CNAME record to forward your domain name to a third-party provider and keep a functional email service with the first provider. It's also important to note that a CNAME record is always a string of words rather than a number as it is regularly mistaken for the A record of the domain name being redirected. One of the major uses of a CNAME record is to direct a domain name which you own through one provider to the servers of some other 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 company.