Onedrive file retention and deletion

Hi Team,

Hope you are doing good.

I have multifold questions with regards to Onedrive retention and Deletion, i am looking to implement a file deletion policy for files older than 5 years in users onedrive.

a. will user be notified before the file is going to be deleted from this policy?
b. We want files to be deleted based on created or modified date, will this work by creating two polices, (one based on each attribute), if we do this, which policy will take precedenceon weather a file is deleted, we have seen a few cases where the created date on file is newer than the modified date attribute, so we only want to delete files based on which ever date is most recent? VasilMichev 

Awaiting response, Thanks.