Setting up a CNAME record for any of the domain names or subdomains you have in the hosting account will permit you to redirect it to a different domain/subdomain. The forwarded domain address will lose all its records - A, MX and so on, and will take the records of the domain name it is being pointed to. In this light, you can't set up a CNAME record to point your domain to a third-party provider and keep a working e-mail service with the first provider. Additionally, it is essential to know that a CNAME record is always a string of words rather than a number as it is generally mistaken for the A record of the domain being forwarded. One of the primary uses of a CNAME record is to point a domain address which you own through one provider to the servers of some other company when you have set up a website with the latter. This way, the website will appear under your own domain name, not under some subdomain provided by the third-party provider.