MC1309743 - Viva Engage: Email updates for frontline users without an active Exchange mailbox

Updated September 16,30, 2026: We have updated the content timeline. Thank you for your patience. 

Introduction

Viva Engage will stop sending email notifications to users who do not have a valid mailbox or routable email destination. Previously, email notifications could still be attempted for these users, resulting in repeated delivery retries, increased load on email systems, and, in some cases, delays to important business communications.

This change reduces unnecessary email traffic, improves delivery efficiency, and helps ensure important communications are delivered reliably and on time.

Users with supported mailbox configurations, including cloud mailboxes, on-premises mailboxes, shared mailboxes, and other routable email destinations, will continue to receive Viva Engage email notifications as expected.

Notifications delivered through supported channels such as Microsoft Teams remain unaffected.

When this will happen:

General Availability (Worldwide): Rollout begins mid-October 2026 (previously end of September 2026 (previously mid-September) and is expected to complete by end of OctoberDecember 2026 (previously end of September)October).

How this affects your organization:

Who is affected:

• Users who do not have a valid mailbox or routable email destination.
• Microsoft 365 admins managing Viva Engage users and mailbox configurations.

What will happen:

• Viva Engage will no longer attempt to send email notifications to users who do not have a valid mailbox or routable email destination.
• Users with cloud, on-premises, shared, or other supported mailbox configurations will continue to receive email notifications as expected.
• This change does not affect the existing email notification experience for users with a valid mailbox or routable email destination.
• Notifications delivered through Microsoft Teams or other supported channels are not impacted.
• The change is enabled by default and applies automatically.
• Organizations may see:
  • Reduced load on email systems and gateways.
  • Fewer retry attempts for undeliverable messages.
  • Improved email delivery efficiency and reliability.

What you can do to prepare:

• No action is required.
• Review your Exchange Online licensing configuration to identify users without mailbox access.
• Evaluate your notification strategy (e.g., Teams vs. Email) for frontline workers.
• Inform helpdesk and user support teams of the expected behavior change.
• Update internal documentation if email notifications are referenced for frontline users.

Compliance considerations:

• Alters how existing customer data is processed: Email notifications to users without mailboxes are no longer attempted, reducing unnecessary processing of undeliverable messages.
• No other compliance impacts identified.