Creating a CNAME record for any one of the domain addresses or subdomains you've got in the hosting account will permit you to direct it to a different domain/subdomain. The forwarded domain name will lose all its records - A, MX and so forth, and will take the records of the domain address it is being directed to. In this light, you simply can't set up a CNAME record to redirect your domain name to a third-party provider and maintain a functional e-mail service with the first hosting company. Additionally, it is very important to know that a CNAME record is always a string of words and not a number because it is often mistaken for the A record of the domain address being redirected. One of the major uses of a CNAME record is to forward a domain name that you own through one provider to the servers of some other company if you have set up a website with the latter. By doing this, the website will appear under your own domain, not under some subdomain provided by the third-party provider.