M365 Changelog: (Updated) Microsoft Defender for Office 365: Quarantine End User Allow and Block list management

MC711335 – Updated March 15, 2024: Microsoft has updated the rollout timeline below. Thank you for your patience.

In Microsoft Defender for Office 365, Microsoft is updating the way end users allow and block emails in Exchange Online. 

This message is associated with Microsoft 365 Roadmap ID 380185.

When this will happen:

Worldwide: Microsoft will begin rolling out late April 2024 (previously late March) and expect to complete by mid-May 2024 (previously late April).

GCC, GCC High and DoD: Microsoft will begin rolling out mid-Mary 2024 (previously late April) and expect to complete by late May 2024 (previously mid-May).

How this will affect your organization:

With one click, end users will block emails from unwanted senders and prevent those emails from showing up in their default quarantine view and in their quarantine notifications. If no admin overrides exist, end users will also be able to allow emails from trusted senders and prevent future emails from those senders from going into quarantine. End users can now review admin any override reasons that lead to quarantined emails.

Figure 1: Allow sender action:

User settings
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Figure 2: Review admin Override reason:

User settings
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Figure 3: Undo Block sender:

User settings
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Figure 4: Allow sender in Quarantine policy:

User settings
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Figure 5: Block sender action eliminated from default Quarantine policies:

User settings
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Figure 6: How to include or exclude messages from blocked sender in Quarantine notification:

User settings
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Figure 7: Quarantined messages from blocked senders are excluded from Quarantine view by default:

User settings
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What you need to do to prepare:

No action is needed to prepare for this change. You may want to notify your users about this change and update any relevant documentation as appropriate.