Setting up a CNAME record for each of the domains or subdomains you have in a hosting account will enable you to forward it to a different domain/subdomain. The forwarded Internet domain will lose all of its records - A, MX and so forth, and will take the records of the domain address it's being redirected to. In this light, you cannot set up a CNAME record to redirect your domain name to a third-party company and keep a working email service with the first provider. It is also important to note that a CNAME record is always a string of words and not a number as it is frequently mistaken for the A record of the domain being redirected. One of the main uses of a CNAME record is to point a domain address that you own through one provider to the servers of another company in case you have set up a website with the latter. That way, the site will appear under your own domain address, not under some subdomain provided by the third-party company.