Purview DLP Behaviours in Outlook Desktop

We are currently testing Microsoft Purview DLP policies for user awareness, where sensitive information shared externally triggers a policy tip, with override allowed (justification options enabled) and no blocking action configured.

We are observing the following behaviours in Outlook Desktop:

1. Inconsistent policy tip display (across Outlook Desktop Windows clients) – For some users, the policy tip renders correctly, while for others it appears with duplicated/stacked lines of text. This is occurring across users with similar configurations.
2. Override without justification – Users are able to click “Send Anyway/Confirm and send” without selecting any justification option (e.g. business justification, manager approval, etc.), which bypasses the intended control.

New Outlook:

Classic Outlook: 

This has been observed on Outlook Desktop (Microsoft 365 Apps), including:

Version 2602 (Build 19725.20170 Click-to-Run)

Version 2602 (Build 16.0.19725.20126 MSO)

Has anyone experienced similar behaviour with DLP policy tips or override enforcement in Outlook Desktop? Keen to understand if this is a known issue or if there are any recommended fixes or workarounds.