It is preferred that you use ImmiAccount to upload any attachments and supporting documents for an application lodged online. The system allows 60 files to be uploaded per person and each file can be up to 5MB in size and include multiple pages.
If you are not able to do this, it is possible to send attachments through the post or via email. However, this will delay processing of that application.
If the department needs to see your original documents or printed copies, this will be requested at a later date.
More information about attaching documents to an online application is available.