Sign in to your Rediffmail Pro control panel. Once signed in you will see modules for each of your domain names.

From the My Account(s) Summary page, click on 'Manage Domain' for the domain for which you wish to setup an MX record.

Click on 'Edit' below Mail Server Mapping on the 'Manage your domain' page.

Click on edit or delete alongside the priority and mail server information you wish to edit or delete.

Click on 'Save Changes'.

You return to the Mail Server Mapping (MX Records) page and your newly edited MX record will appear in the MX records. While your changes will appear in your Name Servers within minutes, please be aware that it can take 24-48 hours for changes to records to be propagated to all Name Servers across the Internet.