Creating a CNAME record for any of the domain addresses or subdomains that you have in a hosting account will allow you to redirect it to a different domain/subdomain. The forwarded domain address will lose all its records - A, MX and so on, and will take the records of the domain address it's being directed to. In this light, you cannot create a CNAME record to forward your domain to a third-party provider and retain a functional email service with the first provider. Additionally, it is essential to know that a CNAME record is always a string of words and never a number because it is frequently confused with the A record of the domain name being redirected. One of the main uses of a CNAME record is to direct a domain you own through one company to the servers of some other company when you have created a site with the latter. By doing this, the website will appear under your own domain name, not under some subdomain provided by the third-party company.