Email Alias

Email Alias

I have added an email alias by:
  1. Clicking on 'Control Panel'
  2. Clicking on 'Mail Administration'
  3. Clicking on 'Alias Details' for a Login Name.
  4. Entering an alias name and clicking Create.
There is a Delivery Failure when testing the new email alias email address from a different email account. What else do I need to do?

Thanks.