The Email Retainer is where emails from the normal GroupWise email go after a certain period of time. It acts like a storage cabinet. So, if you are missing folders or emails, they can likely be found here. Emails in the Retainer will only stay there for 5 years and then be automatically deleted, so if you wish to save emails for longer, you can print them or save them as PDFs to your computer. 

Important Note: You can only access the Email Retainer from school. You cannot access it from an outside internet network (ie: your home).