Setting up a CNAME record for each of the domain names or subdomains you've got in a hosting account will permit 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 it's being directed to. In this light, you simply can't create a CNAME record to forward your domain to a third-party company and retain a working e-mail service with the first provider. Also, it is very important to know that a CNAME record is always a string of words and not a number as it's often mistaken for the A record of the Internet domain being redirected. One of the main uses of a CNAME record is to direct a domain that you own through one provider to the servers of another company when you have created an Internet site with the latter. This way, the Internet site will appear under your own domain name, not under some subdomain provided by the third-party company.