Microsoft 365 Message Center item MC1251200
MC1251200 - (Updated) Microsoft Viva Engage | Email sender domain migration from @yammer.com to @engage.mail.microsoft
Microsoft Viva Engage email sender domains have migrated from @yammer.com to @engage.mail.microsoft (and @eu.engage.mail.microsoft for Europe) as of March 31, 2026. Organizations should update mail flow rules, security gateways, and integrations referencing the old domains. No admin action needed unless custom configurations exist.
- Message Center ID
- MC1251200
- Category
- stay Informed
- Severity
- normal
- Services
- Microsoft Viva
- Tags
- Updated message, Feature update, User impact, Admin impact
- Published
- 2026-03-13
- Last updated
- 2026-04-02
- Expires
- 2026-07-31
Updated April 2, 2026: We have updated the timeline. Thank you for your patience. [Introduction]As part of the final phase of the Viva Engage rebranding, we’re updating the email sender domains used for Viva Engage communications. This change ensures a consistent and secure brand experience across all surfaces and completes the transition from Yammer to Viva Engage.This update was previously communicated in MC1117814, Microsoft Viva Engage | Email sender domain migration from @yammer.com to @engage.mail.microsoft, in September 2025.[When this will happen:]The email sender domain rollout began in early September 2025 for U.S. and EU tenants that were receiving messages from @yammer.com and @eu.yammer.com, respectively. The rollout is complete as of March 31, 2026.A fallback/coexistence period will be in place between September 2025 and April 2026, during which some tenants will remain on the old experience while others transition to the new one.[How this affects your organization:]Who is affected:All Microsoft Viva Engage tenants in U.S., EU, and global regions.All users who receive Viva Engage emails, including notifications, announcements, and digests.Microsoft 365 administrators who manage:Exchange Online mail flow rulesEmail security gatewaysJournaling, archiving, or third-party mail integrations that reference the @yammer.com domain.What will happen:The sender domain for Viva Engage emails will change as follows:From @yammer.com to @engage.mail.microsoft for U.S. and global regions. From @eu.yammer.com to @eu.engage.mail.microsoft for European regions. These new domains are secured with industry standard authentication protocols (e.g., SPF) to help prevent spoofing and ensure reliable delivery.To enhance security and reduce cross-tenant spam, sender addresses will now include a tenant-specific prefix. You may see emails from:noreply_tenant@engage.mail.microsoft (digests, delegates, leader identification, community expert, and other notifications) notifications_tenant@engage.mail.microsoft (community, storyline, and activity notifications) announcements_tenant@engage.mail.microsoft (leadership announcements) These changes apply to all Viva Engage tenants, regardless of license tier (e.g., Viva P1, P2), and affect all Viva Engage emails, including notifications, announcements, and digests.Third-party integrations (e.g., journaling, archiving, or routing systems) that rely on the @yammer.com domain for classification or authentication may be impacted. Any such configurations should be reviewed and updated to recognize the new domains.Screenshot: An example of a new Viva Engage email notification sent from the updated @engage.mail.microsoft domain:[What you can do to prepare:]Review and update the following configurations:Transport rules and email gateways: Update any rules that reference @yammer.com to include the new domains. Exchange filtering: Ensure filtering rules remain effective with the new sender domains. Outlook rules: Inform users that any rules based on @yammer.com will no longer apply. Users can manually update or remove these rules. No admin action is required unless your organization has custom configurations based on the old domain.Learn more: Yammer is evolving to Viva Engage | Viva Engage Blog[Compliance considerations:]No compliance considerations identified, review as appropriate for your organization.