Creating a CNAME record for any of the domain names or subdomains you've got in a hosting account will permit you to redirect it to a different domain/subdomain. The forwarded Internet domain will lose all its records - A, MX and so forth, and will take the records of the domain it's being redirected to. In this light, you cannot create a CNAME record to redirect your domain name to a third-party provider and keep a working email service with the first hosting company. It's also very important to know that a CNAME record is always a string of words and never a number because it is commonly confused with the A record of the domain being forwarded. One of the main uses of a CNAME record is to point a domain which you own through one company to the servers of some other company assuming you have created an Internet site with the latter. By doing this, the website will appear under your own domain, not under some subdomain provided by the third-party company.