If you would like to use a domain name you would need to register the domain with hosting for only R9 pm which will give the option to have up 5 email accounts. You should also consider registering a .co.za domain because you get free domain registration and only pay for the hosting package you choose in the first year.
The other option to get just one email address you can sign up for a Free GB and you will get a free @afrihost.co.za email address. You don't need to use the Free GB for the email to work. It will be active after sign up once your account has been verified.