Creating a CNAME record for each of the domain names or subdomains that you have within a hosting account will enable you to direct it to a different domain/subdomain. The forwarded domain name will lose all of its records - A, MX and so on, and will take the records of the domain it's being directed to. In this light, you simply can't set up a CNAME record to forward your domain name to a third-party provider and retain a working e-mail service with the first hosting company. It is also very important to know that a CNAME record is always a string of words and never a number as it is regularly confused with the A record of the Internet domain being redirected. One of the main uses of a CNAME record is to forward a domain that you own through one company to the servers of another company if you have created a website with the latter. By doing this, the Internet site will appear under your own domain address, not under some subdomain provided by the third-party company.