MC1198702 – Microsoft Outlook: Wait on Send for Data loss Prevention

Product:

Exchange, Microsoft 365 Apps, Outlook, Purview Data Loss Prevention, Windows

Platform:

Online, US Instances, Windows Desktop, World tenant

Status:

Rolling out

Change type:

New feature, User impact, Admin impact

Links:

498920

Details:

Summary:
New Outlook for Windows will support Wait on Send for Data Loss Prevention, blocking email sending until DLP evaluation completes or timeout occurs. This feature is disabled by default and controlled via Exchange mailbox settings, allowing users to multitask during evaluation with configurable override timing. Available early 2026.

Details:
[Introduction]
New Outlook for Windows will support Wait on Send for Oversharing, allowing admins to block email sending if Data Loss Prevention (DLP) policy evaluation is not completed for labeled or sensitive content. The new experience allows for multi-tasking and does not block the user from using New Outlook even when mail is in evaluation.
The wait-on-send experience is controlled through Exchange mailbox parameters:
DLPWaitOnSendEnabled - Boolean (true or false), Default: false
DLPWaitOnSendTimeout - Integer (0-10000 seconds), Default: 9999
Specifies how long Outlook waits for the DLP evaluation to finish before offering an override.
Example: If the value is set to 25 seconds, Outlook will wait up to 25 seconds for the evaluation to complete before allowing the user to override and send the email without waiting for the evaluation to finish.
Note: This does not stop the evaluation after the set time. It simply allows the user to override while the evaluation continues. If the user prefers, they can wait until the evaluation is fully completed.
- When DLPWaitOnSendTimeout = 0, user will immediately see "Send Anyway" in the info bar of mail.
- When DLPWaitOnSendTimeout >= 9999, user will never be allowed to send the email without DLP evaluation getting completed.
This message is associated with Microsoft 365 Roadmap ID 498920.
[When this will happen]
General Availability (Worldwide): Early January 2026 - Late January 2026
General Availability (GCC): Early January 2026 - Early March 2026

Change Category:
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Scope:
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Release Phase:
General Availability

Created:
2025-12-18

updated:
2025-12-18

Task Type

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Docu to Check

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MS How does it affect me

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MS Preperations

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MS Urgency

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MS workload name

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linked item details

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summary for non-techies**

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Direct effects for Operations**

Email Sending Delays
If the Wait on Send feature is enabled without proper preparation, users may experience delays in sending emails while waiting for DLP evaluation to complete, leading to frustration and potential disruption in workflow.
   - roles: End Users, IT Administrators
   - references: https://learn.microsoft.com/purview/dlp-ol365-win32-policy-tips#wait-on-send-dialog-support-for-oversharing-for-outlook-for-microsoft-365, https://www.microsoft.com/microsoft-365/roadmap?filters=&searchterms=498920

User Experience Degradation
Without preparation, users may not be aware of the new wait-on-send behavior, leading to confusion and a negative impact on user experience as they may not understand why their emails are not sending immediately.
   - roles: End Users, Support Staff
   - references: https://learn.microsoft.com/purview/dlp-ol365-win32-policy-tips#wait-on-send-dialog-support-for-oversharing-for-outlook-for-microsoft-365, https://www.microsoft.com/microsoft-365/roadmap?filters=&searchterms=498920

Configutation Options**

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Data Protection**

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explanation for non-techies**

Imagine you're sending a letter through the postal service, but before it goes out, there's a quick check to ensure you're not accidentally sending sensitive information, like your bank details or a confidential business plan. This is similar to what Microsoft Outlook's new feature, "Wait on Send for Data Loss Prevention (DLP)," aims to do for emails.

When you hit "send" on an email, the system will pause to evaluate if the email contains any sensitive information that shouldn't be shared. Think of it as a security guard checking your letter before it leaves the post office. If the check isn't completed in a set amount of time, you have the option to override and send the email anyway, much like deciding to send your letter even if the guard hasn't finished their review.

This feature is designed to prevent accidental data leaks by ensuring emails are reviewed for sensitive content before they are sent. It's important to note that this feature is turned off by default, meaning it won't automatically start checking your emails unless an administrator enables it. This gives organizations control over whether they want to implement this additional layer of security.

While the email is being evaluated, you can continue using Outlook for other tasks, similar to how you might continue writing other letters while waiting for the security guard to finish checking one. If the evaluation takes too long, you can choose to send the email without waiting for the check to complete, depending on how your organization has set up the feature.

This new feature is expected to be available in early 2026, giving organizations time to decide if they want to adopt it and configure their settings accordingly. It's a way to help protect sensitive information without significantly disrupting your workflow.