Duplicate detection is a feature that prevents you from having two identical files within your Library. When this feature is turned on, the duplicate asset will automatically be archived and you will receive a notification by email and in your profile.
When Media Manager recognizes the duplicate (i.e. the file is an exact match to an existing asset already uploaded) it will automatically archive the asset. You will be able to see in your 'Manage Deleted Asset' modal that the asset was deleted via duplicate detection.
An email will be sent on the hour if any duplicate assets were uploaded and archived.