Prevent user from deleting emails. When the user deletes emails it goes into the Deleted Items but it is still recoverable

Plans that include Litigation hold:
Exchange Online Plan 2, Microsoft 365 E3, E5, A3 or A5
otherwise you need Exchange Online Archive for Exchange Online with your current plan

To enable Litigation hold
Open Exchange Online Admin
click Mailboxes
click on a User
click Others tab
click Manager Litigation Hold
Turn it on

To access the deleted emails you need to login to the user’s mailbox
Open Deleted Items folder
you will see Recoverable Items