MC1152320 - Microsoft Defender for Office 365: Enhanced email entity page experience

Introduction:

We’re introducing a streamlined experience for the email entity page in Microsoft Defender for Office 365. This update improves how users navigate between email records, reducing friction and enhancing productivity. The changes are based on customer feedback to simplify workflows and reduce time spent switching between tabs.

When this will happen:

• Public Preview: We will begin rolling out late September 2025 and expect to complete by late October 2025.
• General Availability (Worldwide): We will begin rolling out early November 2025 and expect to complete by late November 2025.

How this affects your organization:

Who is affected:

• Security analysts and administrators using Microsoft Defender for Office 365.
• Users accessing email entities via security.microsoft.com (Explorer, Advanced Hunting, Quarantine, etc.).
• This feature is available to tenants licensed with Microsoft Defender for Office 365 Plan 2 or with Microsoft security licenses such as E5 and above.

What will happen:

• Email entity pages will open in a shared browser tab instead of launching a new tab for each record.
• A parent-child relationship is established between the main security.microsoft.com tab and the shared email entity tab. If the same or new email is opened again from the parent tab, it switches to the already-open shared tab.
• If the parent tab is closed or refreshed, this relationship is reset. A new shared email entity tab will be opened the next time an email entity is accessed from the refreshed or newly opened parent tab.
• Navigation positions within each email entity are retained during the session (e.g., Analysis tab vs. Timeline tab).
• A new “Email preview” tab is added alongside “Similar emails,” allowing persistent preview even when switching tabs.
• Each email entity now has a unique URL, enabling direct sharing via Teams or opening in a new browser tab.

What you can do to prepare:

• No action is required from end users or administrators.
• You may wish to inform helpdesk staff of the new navigation behavior for email entities.

Learn more: to be updated The Email entity page in Microsoft Defender for Office 365 - Microsoft Defender for Office | Microsoft Learn

Compliance considerations:

No compliance considerations identified, review as appropriate for your organization.