check before: 2025-09-01
Product:
Exchange, Microsoft Viva, Microsoft Viva Engage, Outlook, SharePoint
Platform:
Online, World tenant
Status:
Launched
Change type:
Admin impact, Feature update, Updated message, User impact
Links:
Details:
Summary:
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.
Details:
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.
Change Category:
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Scope:
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Release Phase:
Created:
2026-03-17
updated:
2026-04-03
Task Type
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Docu to Check
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MS How does it affect me
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summary for non-techies**
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Direct effects for Operations**
Email Delivery Issues
If the email sender domain is changed without updating mail flow rules and security gateways, users may not receive important notifications and announcements from Viva Engage, leading to missed communications.
- roles: Microsoft 365 Administrators, End Users
- references: https://techcommunity.microsoft.com/blog/viva_engage_blog/yammer-is-evolving-to-viva-engage/3738825
User Experience Disruption
Users with Outlook rules based on the old @yammer.com domain will find those rules ineffective, causing confusion and potential loss of important emails.
- roles: End Users, IT Support Staff
- references: https://techcommunity.microsoft.com/blog/viva_engage_blog/yammer-is-evolving-to-viva-engage/3738825
Integration Failures
Third-party integrations that rely on the old domain for classification or authentication may fail, disrupting workflows and data processing.
- roles: Microsoft 365 Administrators, Integration Developers
- references: https://techcommunity.microsoft.com/blog/viva_engage_blog/yammer-is-evolving-to-viva-engage/3738825
Configutation Options**
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Opportunities**
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Potentional Risks**
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Data Protection**
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IT Security**
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Hypothetical Work Council Statement**
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DPIA Draft**
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explanation for non-techies**
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change history
| Date | Property | old | new |
| 2026-04-03 | MC Messages | [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 expected to complete by mid‑April 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. | 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. |
| 2026-04-03 | MC Title | Microsoft Viva Engage | Email sender domain migration from @yammer.com to @engage.mail.microsoft | (Updated) Microsoft Viva Engage | Email sender domain migration from @yammer.com to @engage.mail.microsoft |
| 2026-04-03 | MC Last Updated | 03/13/2026 23:45:14 | 2026-04-03T01:29:50Z |
| 2026-04-03 | MC MessageTagNames | Feature update, User impact, Admin impact | Updated message, Feature update, User impact, Admin impact |
| 2026-04-03 | MC Summary | Microsoft Viva Engage is migrating email sender domains from @yammer.com to @engage.mail.microsoft (and @eu.yammer.com to @eu.engage.mail.microsoft) between September 2025 and April 2026. This affects all Viva Engage tenants and users, requiring updates to mail flow rules, security gateways, and third-party integrations referencing the old domains. | 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. |
Last updated 1 week ago ago
