I have recently created a subdomain in cPanel.
I want to use that subdomain for office 365 email service. I could not create the MX record for that subdomain in cPanel's zone editor. How do I do that?
The MX Record always have to be a string of characters, which resolves to the IP address of the Mail Service where you would like to receive emails.
Usually it can be edited by your HOSTING COMPANY if you wish to use another email provider.
So you must register with office 365 email service, and ask your HOSTING COMPANY to change your MX records to what the office 365 is giving you.
Also, you yourself can change MX records if you have an updated CPANEL from "Zone Editor". But you must be sure what you are doing as they are important for the receiving of your emails.
Here is an example:
CPANEL > Zone Editor > Manage > MX >