If you want to delete an email account, you can do this from the Email Accounts tool in cPanel. You will find it under the Mail category.
- Log into cPAnel
- Locate Email Accounts
- find the account you want to remove in the table of registered email accounts and press the Delete link next to it.
- You will be taken to a page which asks you for confirmation. Confirm, if you're sure you want to delete the account.