In Office 365, is there a way to run a power shell command against a get-content txt file containing UPNs, and report back accounts that's are NOT listed in the get-content txt file, and export the results to CSV?
Reason I ask, this company I am helping migrate to office 365 never did any AD cleanup of terminated employees. The AD accounts weren't ever deleted/disabled, but just had passwords reset. So they have been migrating accounts/mailboxes to the cloud and wasting E3 licenses.
I want to reclaim those non-employed user licenses and delete them from AD/Exchange so I can use those licenses on current employees that still need to be migrated.