Issues with Sensitivity Labels in Microsoft Purview: GUID Display, Power BI Files, and Outlook Enforcement

Question

Dear professional,

I would like to seek your support and guidance on the following three issues related to Microsoft Purview and sensitivity labels. These challenges involve cross-tenant label recognition, Power BI exported files, and Outlook email enforcement. Your insights or recommended solutions would be greatly appreciated.

Question 1: Sensitivity Label Displayed as GUID for External Files

When we receive files from other organizations that already have sensitivity labels applied, Microsoft Purview shows the label as a GUID (3281c594-xxxx-xxxx-xxxx-xxxxxxxxxxx) instead of the actual label name. Is there a way to map or resolve this so Purview displays the correct label name across tenants?

Question 2: Power BI Exported Files Detected with GUID Instead of Label

Files generated from Power BI reports do not appear to have a sensitivity label applied, but Purview detects a label as a GUID (3281c594-xxxx-xxxx-xxxx-xxxxxxxxxxxx). Why does this happen, and how can we ensure Power BI exported files are properly classified with the correct sensitivity label?

Question 3: New Outlook Occasionally Sends Emails Without Sensitivity Labels

We have a policy requiring sensitivity labels on emails, but occasionally, when using the new Outlook, emails are sent without any label applied. Why does this occur, and what steps can we take to enforce labelling consistently in Outlook?

Answer 1

Question 1: Sensitivity Label Displayed as GUID for External Files

When files from other organizations are received with sensitivity labels, the GUID display instead of the actual label name occurs because the label metadata is tied to the tenant that created it. Microsoft Purview reads the label metadata, but if the receiving organization does not have a corresponding label defined, it will show the GUID instead. Unfortunately, there is no direct way to map or resolve this across tenants, as each organization maintains its own labeling structure.

Question 2: Power BI Exported Files Detected with GUID Instead of Label

The issue where Power BI exported files show a sensitivity label as a GUID rather than the label name can happen if the label is not recognized by the receiving tenant. This can occur when the label has not been defined in the receiving organization’s Microsoft Purview Information Protection setup. To ensure that Power BI exported files are properly classified, make sure that the sensitivity labels used in Power BI are also defined in the receiving organization’s labeling policy.

Question 3: New Outlook Occasionally Sends Emails Without Sensitivity Labels

The occurrence of emails being sent without sensitivity labels in the new Outlook can be attributed to several factors, including user error, system glitches, or configuration issues. To enforce labeling consistently, ensure that the sensitivity label policy is correctly configured and that users are trained to apply labels. Additionally, consider checking the settings in the Microsoft Purview portal to ensure that the policies are being enforced as intended.

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References:

• Manage sensitivity labels in Office apps
• Sensitivity labels troubleshooting

Answer 2

Hi @Noeumkhouch Prengratana

Thank you for contacting to Microsoft QA, below are few detailed mitigation steps that may help on question -

1. External Files Showing Sensitivity Labels as GUIDs

Why it happens: Files coming from another organization carry their own label IDs. If your tenant doesn’t know that label, Purview can only show the GUID instead of the label name.

How to fix it: Turn on cross‑tenant label mapping in Purview or create a matching label in your tenant using the same GUID. Once you do this, Purview will correctly translate the GUID into the actual label name.

End result: All externally labelled files will show readable label names instead of GUIDs.

2. Power BI Exported Files Showing GUID Instead of Label

Why it happens: Power BI embeds the label ID (GUID) into exported files, not the label name. If the same label doesn’t exist in your tenant, Purview displays only the GUID.

How to fix it: Make sure the same sensitivity label exists in your tenant or enable cross‑tenant label mapping. Also confirm that Power BI’s sensitivity labeling features (including “apply sensitivity label to exports”) are enabled.

End result: Power BI exports will consistently show the correct sensitivity label in Purview.

3. New Outlook Sending Some Emails Without Sensitivity Labels

Why it happens: The new Outlook relies on cloud-based labeling policies, and sometimes the mandatory label enforcement doesn’t load before the email is sent. Switching between Outlook versions, slow policy sync, or mobile clients can also bypass labeling.

How to fix it: Strengthen enforcement by:

• Turning on “require a label before sending” in the label policy.
• Adding a DLP rule that blocks unlabeled emails.
• Ensuring users only send mail through Outlook clients that support mandatory labeling.
• Applying Intune App Protection Policies for mobile devices.

End result: Emails cannot be sent without a sensitivity label—regardless of Outlook version or device.

Summary

These recommendations address the underlying architecture behind each issue, so once implemented, you should see consistent and predictable behavior across Purview, Power BI, and Outlook. This will eliminate surprise GUIDs, ensure proper classification, and enforce mandatory labeling across all platforms.