Creating a CNAME record for any of the domain names or subdomains you have in the hosting account will allow you to forward it to a different domain/subdomain. The forwarded domain address will lose all its records - A, MX and so forth, and will take the records of the domain name it is being pointed to. In this light, you cannot set up a CNAME record to forward your domain name to a third-party provider and maintain 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 because it is generally wrongly identified as 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 company to the servers of another company if you have created a site with the latter. This way, the website will appear under your own domain name, not under some subdomain provided by the third-party provider.