AzureFeeds

As part of the final phase of the Yammer to Viva Engage rebranding, we are updating the email sender domains used for all Viva Engage communications. This change ensures a consistent and secure brand experience across all surfaces and completes the transition from the Yammer brand to Viva Engage. Please see Message ID MC1117814 for earlier communications on this release.

The new email domains continue to leverage industry-standard email authentication (such as SPF) to help prevent tenant spoofing and improve deliverability.

When will this happen?

The rollout of the new email sender domains will occur in phases over several months starting in late August 2025:

We plan to complete the transition by the final quarter of 2025 but may adjust the timeline based on feedback. Any updates will be sent via the Message Center.

During this transition you should expect to receive emails from both the old and new domains. This is very important if your tenant has custom email rules or is processing emails sent by Engage in a special manner. Please ensure that you are prepared to receive emails using the old and new sender domains until communication has been sent notifying you of the completion of these changes.

How this affects emails across mailbox and organizations

All emails from Viva Engage will now come from a new domain instead of yammer.com or eu.yammer.com The exact sender domain depends on the data residency for your Viva Engage network:

• US geo: from @yammer.com to @engage.mail.microsoft


• EU geo: from EU.yammer.com to EU.engage.mail.microsoft

In addition to the domain change, Viva Engage email addresses will now include a tenant-specific prefix to help differentiate your organization’s environment such as test and production tenants. This prefix will use your organization’s tenant name in Microsoft Entra ID and will appear in the sender address. For example, fabrikam.onmicrosoft.com will result in a “fabrikam” prefix. Continuing with this example, sender addresses may include:

• noreply_fabrikam@engage.mail.microsoft – for digest emails and delegated notifications.


• notifications_fabrikam@engage.mail.microsoft – for community posts, storyline updates, and other user activity notifications.


• announcements_fabrikam@engage.mail.microsoft – for leadership announcements and other broad communications.

For networks in the EU geo, you should change the sender domain in the examples above to noreply_fabrikam@eu.engage.mail.microsoft, etc.

Including this identifier makes it easier for admins, users, and mail systems to distinguish between tenants, reducing confusion and improving traceability. It also adds an additional layer of protection by making it easier to identify and authenticate emails originating from your tenant.

Scope of impact: 

This change applies to all Viva Engage customers and all email notification types, regardless of your Viva license tier (Viva Engage Core, Viva Suite, etc.).

 It affects all Viva Engage emails, including user notifications, community announcements, storyline digests, and any other Viva Engage–generated emails. Most end users will only notice that the “From” address looks different

Custom email transport rules: If you rely on specific email address formats in rules configured within your tenant, please ensure that the configuration is updated to cover both the old and new email address formats accounting for the data residency of your network.

Third-party integrations: If your organization uses any third-party services (such as email journaling/archiving systems, security gateways, or custom email workflows) that filter or classify emails based on the sender domain, those will need adjustment to include the new email sender domain. Any tool explicitly looking for only @yammer.com or EU.yammer.com in email addresses will fail to recognize the new addresses. You should review such configurations and update them to accept or recognize the new @engage.mail.microsoft and EU.engage.mail.microsoft domains. This will ensure continuity in archiving, compliance journaling, or application of custom routing rules that were targeting the old domain.

Finally, note that this is not an optional change, it’s an automated part of the service rebranding. After the coexistence period, emails from the old Yammer domains will stop. We will communicate via the Message Center at the completion of this transition so that you know when the old email address has been discontinued.

What you need to do to prepare

Admins should review and update the following configurations before and during the rollout:

1. Email Transport Rules / Mail Flow Rules: Update any Exchange transport rules, mail flow policies, or email gateway allowlists that reference @yammer.com (or EU.yammer.com) to also include the new domain(s) @engage.mail.microsoft and EU.engage.mail.microsoft. This ensures that automated rules (for encryption, forward, etc.) continue to work with the new sender addresses. For example, if you have a rule that flags or redirects Yammer emails, edit its conditions to accept the new domain as well.


2. Security Filters: Check your anti-spam or email security filtering configurations. The new domains are Microsoft-managed and authenticated, so in general they should be treated as trustworthy senders. If your organization had any custom filter allowing all @yammer.com mail, you should add the new domains to those allowlists. Likewise, if you blocked @yammer.com anywhere (some organizations temporarily block Yammer emails prior to launch), you’ll need to update those blocks to use the new domain.


3. Outlook Inbox Rules (User Mailbox Rules): Inform your users that any personal Outlook rules they created that filter or sort emails by the sender domain will need to be updated. For instance, a user might have an Outlook rule moving all Yammer emails to a folder. After the change, that rule (looking for @yammer.com) would no longer catch the notifications. Users should update such rules to the new domain or adjust their logic. (If a user does nothing, the worst case is that Viva Engage emails will start landing in their inbox instead of the expected folder.)


4. Safe Senders and Allow Lists: To proactively prevent any Viva Engage notifications from being misclassified as junk email and treated as external, consider adding the new domain to your organization’s safe sender lists. In Exchange Online, this might mean adding engage.mail.microsoft (and the EU variant if applicable) to tenant allow lists. See more here- https://learn.microsoft.com/en-us/exchange/mail-flow-best-practices/manage-accepted-domains/manage-accepted-domains   
   Users can add the new addresses to their personal Outlook Safe Senders list. Email addresses and domains on the Safe Senders list are never treated as junk mail. For instructions, see Add recipients to safe sender list in Outlook. This step can help ensure smooth delivery during the transition.


5. No action needed if no custom configurations: If your organization has no custom mail rules or integrations related to Yammer, then in most cases no administrative action is required for basic email delivery. The domain change will happen automatically.

For admins, communicating these changes in advance to users in your organization is highly recommended.

Compliance considerations

No new compliance or privacy impact has been identified with this change. The content of the emails remains the same; only the sender domain is changing. Data residency and compliance for Viva Engage continue to follow the existing policies and region of your network as the domain rebranding won’t affect that.

As always, you should review this change against your organization’s policies. For example, if your organization had any internal compliance rule specifically referencing the old domains, update those references. Otherwise, standard email compliance (retention, eDiscovery, auditing) for Viva Engage messages is unaffected by the domain change.

By updating your configurations and informing users, you can ensure a seamless transition as Viva Engage completes its rebranding. After the transition is complete, all your Viva Engage emails will arrive under the new domain names, offering a more coherent experience.

Learn more

• For more background on the Viva Engage rebranding journey, see the blog post “Yammer is evolving to Microsoft Viva Engage” on the Microsoft Tech Community.


• Official documentation is updated to reflect these new domains. Please refer to the Message ID (MC1117814) for the Viva Engage email rebranding updates.