Please refer to the following article to add/change the MX record in cPanel. You need to point the MX record to your email service to run your email service.
Step 1: Log in to your cPanel. Please refer to how to log in to cPanel?
Step 2: Inside the Domain section, click on the zone editor.
Step 3: At the zone editor, go to the domain for which you want to add or change the MX record and click on the manage button.
Step 4: If you already have an MX record for the same domain, you will need to click on the edit button.
Step 5: Click on the Add Record button to add a new record in cPanel and select the MX in the record type.
Step 6: In the priority field, add the required priority for your email server. Low priority will increase the chance of receiving the email in your email service. Enter the mail service record in the Destination field. Finally, click on the Add record button to save the changes.
Step 7: You will see a success message in the green belt once you add the record.
