CPanel manages your e-mail through its own mail server. However, by altering your MX (Mail Exchange Record) Entry you can point your e-mail to another mail server, if this is required.
Note: CPanel will not be able to manage your e-mail if you change your MX Entry setting. Do not change your MX Entry unless you know what you are doing.
To alter your MX Entry setting:
Click on the Modify Mail Exchanger (MX Entry) link in the Mail area.
Click on the Change an MX Entry link.
Enter the domain name of the new MX Entry in the available field.
Note: You can only change the entry to a domain name (e.g. yourdomain.com), not an IP (Internet Protocol) address.
Click on the Change button.