Setting up a CNAME record for any one of the domain addresses or subdomains that you've got in the hosting account allows you to redirect it to a different domain/subdomain. The forwarded domain will lose all of its records - A, MX and so on, and will take the records of the Internet domain it's being redirected to. In this light, you can't set up a CNAME record to direct your domain to a third-party provider and retain a working email service with the first provider. It is also essential to know that a CNAME record is always a string of words and not a number as it is generally mistaken for the A record of the domain being forwarded. One of the main uses of a CNAME record is to direct a domain name which you own through one provider to the servers of some other provider when you have set up an Internet site with the latter. This way, the website will appear under your own domain, not under some subdomain provided by the third-party company.