Procedure
You can create a Mail Forwarder within a cPanel account by going to:
Email >> Forwarders >> Click on the Add Forwarder button
You will want to specify the first portion of the email account within the text box, that is directly below the following section:
Address to Forward:
For example, if the email account is named you@domain.com, you will type pluto.
You will want to specify the email account that you want to forward emails to within the following section:
Forward to Email Address
For example, if you want to forward emails from you@domain.com to spouse@domain.com, you will want to add spouse@domain.com within the following section:
Forward to Email Address