Adding people to an email group.

Hintsteiner, Oliver 20 Reputation points
2026-06-09T08:00:23.9366667+00:00

Hello. I’d like to add someone to an existing email group, but I keep getting the following error message:

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What should I do now?

Exchange Online
Exchange Online

A cloud-based service included in Microsoft 365, delivering scalable messaging and collaboration features with simplified management and automatic updates.

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Answer accepted by question author
Anonymous
2026-06-09T08:47:25.5466667+00:00

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Hello @Hintsteiner, Oliver

I would like to first clarify that this is a user-to-user support forum, and we are not Microsoft support. Moderators here do not have backend access and cannot directly intervene in Microsoft products or perform escalations. We can only provide technical guidance and best-practice recommendations based on reported issues.

Could you please let me know which Exchange version you are using?

Based on the error message in your screenshot, it looks like this distribution group was created in an on-premises environment. If that’s the case, any changes (like adding members) need to be performed on-premises as well.

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Have you tried updating the user from your on-premises server? Alternatively, you can try using PowerShell on your on-prem Exchange server: Add-DistributionGroupMember -Identity "GroupName" -Member "******@domain.com"

After making the change, please allow time for synchronization (usually around 30 minutes), or you can manually trigger a sync: Start-ADSyncSyncCycle -PolicyType Delta

Please try the suggestions above and share your feedback. I’ll be happy to assist further.

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

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  1. AI answer

    2026-06-09T08:00:36.8166667+00:00

    The error indicates that the distribution group is synchronized from an on‑premises directory, so membership changes can’t be made in Outlook on the web or directly in Exchange Online. The group must be managed in the on‑premises environment.

    To add the person to the email group:

    1. Have the on‑premises Active Directory/Exchange administrator open the on‑premises management tools (for example, Exchange Management Console/Exchange Admin Center or AD Users and Computers, depending on how groups are managed).
    2. Locate the distribution group that corresponds to this email group.
    3. Add the user as a member of that group on‑premises.
    4. Wait for directory synchronization (Microsoft Entra Connect) to run, or trigger a sync if allowed in the environment.
    5. After sync completes, verify in Outlook/Outlook on the web that the new member appears in the group.

    If the user object itself is also synchronized from on‑premises and is intended to be a guest/external user instead, the administrator may need to adjust how that object is represented, similar to the guidance for guest users that already exist in Microsoft Entra ID: remove or move the on‑premises object so that it can be recreated in the cloud in the correct form.

    References:

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