Creating a CNAME record for each of the domain names or subdomains that you've got within a hosting account will permit you to direct it to a different domain/subdomain. The forwarded Internet domain will lose all its records - A, MX and so on, and will take the records of the domain it's being forwarded to. In this light, you simply can't create a CNAME record to redirect your domain to a third-party provider and retain a functional e-mail service with the first hosting company. Also, it is important to note that a CNAME record is always a string of words and never a number because it is regularly mistaken for the A record of the domain being forwarded. One of the major uses of a CNAME record is to point a domain you own through one provider to the servers of another provider if you have set up a site with the latter. This way, the Internet site will appear under your own domain address, not under some subdomain provided by the third-party company.