How do I delete a user's account from the organization?

How do I delete a user's account from the organization?

When a user has resigned from the organization, you can remove the user account from the organization. When you remove the user account from the organization, the user's data will be removed from all the associated apps. If you are sure to delete the user account, follow the steps below: 
  1. In the Mail Control Panel, navigate to the User Details section.
  2. Select the users whose accounts you want to delete.
  3. Click Delete from the top menu.
  4. You can also click the 'Delete user' icon across the users name.
Refer here for more details.