First, you need to create a sub-domain. Here is an article which can assist you in case you dont know "How to create a sub-domain".
3) Click on the settings icon on the right hand side of your hosting service and select "View Details".
5) Once in to the cPanel interface, scroll down to the Email tab within the cPanel interface. Click Email Accounts.
6) Now, click on the blue button on the right hand side labelled "Create" to create a new account.
7) Here, select the domain or sub-domain you want, than you can create a unique email address specific to your domain or sub-domain name. In order to create an account, simply fill out the requested fields.