Office 365 has some really nice capabilities now, one of which is eDiscovery where you can place legal holds on mailboxes, OneDrive accounts.
https://protection.office.com
1. How to place a mailbox on legal hold in Office 365
a) Open the Office 365 exchange admin console
b) Under resources, select user mailboxes, select the user who will be placed on legal hold.
c) Click on Mailbox Features and scroll down to "Litigation Hold" and select "Enable". Click Save.
2. How to place OneDrive on legal hold.
a)
