Creating a CNAME record for any of the domain addresses or subdomains you've got in a hosting account allows you to forward it to a different domain/subdomain. The forwarded domain address will lose all of its records - A, MX and so forth, and will take the records of the domain name it's being directed to. In this light, you simply can't create a CNAME record to direct your domain name to a third-party provider and retain a functional e-mail service with the first hosting provider. Also, it is essential to know 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 Internet domain being forwarded. One of the major uses of a CNAME record is to forward a domain address you own through one company to the servers of another company in case you have created an Internet 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.