Outlook IMAP: when i delete emails it is permanently gone. no recycle bin

Outlook IMAP: when i delete emails it is permanently gone. no recycle bin

when we delete emails in outlook, it is permanently deleted!!  it does not go to trash nor recycle bin.  

this is a problem,  one of our staff just accidentally deleted her emails in her inbox.  all of it.  

since outlook deletes everything permanently,  we do not know where to find her deleted emails.

please help.  can you restore her emails back?  when can we get her old emails and how can i get her old emails back?

how can we fix the delete (should go to recylce bin or trash first) issue to avoid this problem in the future.

pls help.