Why Some Purview DLP Policies Need Days to Start Working

While testing the new DLP capabilities to block sharing to users and domains and stop Copilot from using external email, it was noticeable how long it took before policies became active. DLP policy synchronization to workloads is reasonably work (and getting faster), but these policies have a new retrospective effect that requires workloads to process files and messages to stop them being available. It’s a new twist to the DLP story.

https://office365itpros.com/2026/09/11/dlp-policies-take-time/