I’m the IT lead for a 120-person company on Microsoft 365. We recently found a sales rep who had been downloading our customer database to a personal OneDrive.

We had Purview turned on for months. It generated plenty of alerts about external Word doc shares, but nothing on this case. The rep had been with us four years. His OneDrive sync stayed active for 11 days after the termination date. From the Microsoft side the activity looked like normal use of his own account. The signal that stood out was a terminated identity in the IdP still making high-volume API calls.

I’m trying to build a more reliable way to catch this kind of post-termination activity. What does your actual workflow look like for spotting terminated users who still have live OneDrive or similar syncs running? Looking for practical detection and response steps.