Handling MailBox and OneDrive data for relieving user

Hi,

One of our user leaving our organization. He seems to be working for a very long time I found more than 10GB of data in his OneDrive for business file with more than 50 thousands files.

He soon to be leaving my manager told me to find a way to access his OneDrive and mail after his retirement since he will be receiving emails after his retirement.

So, What will be the best way to handle a relieving user OneDrive and mail box?

Hey there!
You can put the mailbox on hold, then delete the user - this provisions it as Inactive mailbox and will preserve all the data in it: Create and manage inactive mailboxes - Microsoft Purview (compliance) | Microsoft Learn

But they are a bit harder to work with if you need frequent access to the data. Some more considerations here: https://practical365.com/exchange-online/shared-mailboxes-vs-inactive-mailboxes-departed-users/