Classic Outlook to New Outlook: Block PDF Printing for Mandatory Labels – Current compliance workaround

When your organization enforces mandatory sensitivity labels in Outlook, you need to block users from printing or saving emails as PDF files to maintain compliance. In classic Outlook, Group Policy settings can prevent PDF printing. The new Outlook for Windows does not support those same Group Policy settings, creating a compliance gap. This article explains the technical difference between classic Outlook and new Outlook regarding PDF printing controls and provides the current workaround to block PDF printing in new Outlook.

Why Classic Outlook and New Outlook Handle PDF Printing Differently

Classic Outlook (the traditional Win32 desktop application) uses Group Policy administrative templates to control features like printing to PDF. These policies are applied through Active Directory or local Group Policy Editor and modify registry keys that classic Outlook reads at startup. The policy setting “Disable Print to PDF” is located under User Configuration > Administrative Templates > Microsoft Outlook 2016 > Miscellaneous.

New Outlook for Windows is a rebuilt application based on web technologies. It does not read the classic Outlook Group Policy templates. Instead, new Outlook relies on cloud-based policy settings managed through the Microsoft 365 admin center or directly via registry keys that the new Outlook app checks. Because the two applications use different configuration engines, a Group Policy that works in classic Outlook does not affect new Outlook.

When mandatory sensitivity labels are applied to emails, the compliance requirement is that users cannot remove the label or print the email without the label appearing on the printed output. Blocking PDF printing prevents users from bypassing the label by saving the email as a PDF and then printing that PDF without the label.

Current Workaround to Block PDF Printing in New Outlook

Microsoft has not yet released a dedicated Group Policy setting for new Outlook to block PDF printing. The current workaround is to set a registry key directly on each user’s machine. This key tells new Outlook to disable the Print to PDF option in the Print dialog.

1. Open Registry Editor
   Press Windows key + R, type regedit, and press Enter. Click Yes if prompted by User Account Control.
2. Navigate to the Outlook Options key
   Go to HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Options\General. If the General key does not exist, right-click the Options key, select New > Key, and name it General.
3. Create the DisablePrintToPDF DWORD
   Right-click in the right pane, select New > DWORD (32-bit) Value. Name it DisablePrintToPDF and set its value to 1.
4. Restart Outlook
   Close and reopen Outlook. The Print to PDF option should no longer appear in the Print dialog.

Using Group Policy to Deploy the Registry Setting

To apply this registry key to multiple users, use Group Policy Preferences. Create a new Group Policy Object and navigate to Computer Configuration > Preferences > Windows Settings > Registry. Add a new Registry preference item with the following settings:

• Action: Update
• Hive: HKEY_CURRENT_USER
• Key Path: Software\Microsoft\Office\16.0\Outlook\Options\General
• Value name: DisablePrintToPDF
• Value type: REG_DWORD
• Value data: 1

Set the preference to apply at user logon. This ensures the registry value is present before Outlook starts.

Verifying the Setting

After applying the registry key and restarting Outlook, open an email and click File > Print. In the Printer dropdown, Microsoft Print to PDF should not appear. If it still appears, confirm the registry key exists and is set to 1. Also check that no other policy overrides the setting.

If the Workaround Does Not Block PDF Printing

New Outlook Still Shows Print to PDF

If the Print to PDF option remains available, the registry key may not be applied to the correct hive. Verify the key is under HKEY_CURRENT_USER, not HKEY_LOCAL_MACHINE. New Outlook reads user-level registry settings. Also check if the user has permission to write to that registry path.

Classic Outlook and New Outlook on the Same Machine

If both classic Outlook and new Outlook are installed, the registry key DisablePrintToPDF under the path above affects only new Outlook. To block PDF printing in classic Outlook, use the Group Policy setting for classic Outlook separately. The two applications do not share this registry key.

User Can Print Using Other PDF Printers

The registry key DisablePrintToPDF only removes the Microsoft Print to PDF printer from the Outlook Print dialog. It does not block third-party PDF printers such as Adobe PDF or Foxit PDF. To block those, use Group Policy to restrict printer installation or use Windows AppLocker to block specific printer drivers.

Mandatory Label Still Removed After Print

Blocking PDF printing prevents one bypass method. Users could still take a screenshot of the email or copy the content to another application. For full protection, combine PDF printing restrictions with Information Rights Management (IRM) settings in the sensitivity label itself. Configure the label to prevent copying and screen capture where possible.

Item	Classic Outlook	New Outlook
Configuration method	Group Policy administrative templates	Registry key or cloud policy
Group Policy path	User Configuration > Administrative Templates > Microsoft Outlook 2016 > Miscellaneous	Not supported
Registry key	Not required for classic Outlook	HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Options\General\DisablePrintToPDF = 1
Blocks Microsoft Print to PDF	Yes, via policy	Yes, via registry
Blocks third-party PDF printers	No	No
Requires restart	Yes, after policy refresh	Yes, after registry change

You can now block PDF printing in new Outlook for Windows when mandatory sensitivity labels are enforced. Apply the registry key DisablePrintToPDF to each user’s machine or deploy it through Group Policy Preferences. For a more complete compliance solution, configure sensitivity labels to restrict copying and screen capture in addition to blocking PDF printing. Monitor the Microsoft 365 Roadmap for a native Group Policy setting for new Outlook that will replace this registry workaround in a future update.