To create an email account:
- Log into cPanel.
- In the Mail section, click Email Accounts.
- In the Email field, type the name you want and select the domain name from the adjacent drop-down menu.
- In the Password fields, type the desired password twice.
- Make a selection for Mailbox Quota.
- Click Create Account.
The same steps work for creating email accounts for your primary domain, addon domains and subdomains.
More details are availble on the cPanel documentaion