Moderated Distribution lists and Allowed senders

Alex C 56 Reputation points

We have some nested distribution groups in Office 365 with the top group requiring moderation and some child groups only allowing messages from allowed senders. Example:

  1. Company-All group requires moderation (Bob and Jane), allows messages from all senders, and has a bunch of child groups
  2. Department-Finance group is a member of Company-All, does not require moderation, but only allows certain senders (Bob, Jane, and Mary)

Ed recently sent a message to Company-All. One of the moderators (I'm not sure who) approved the email. Everyone in the company received it, including Department-Finance.

Any idea how this is possible since only Bob, Jane, and Mary are allowed to send to Department-Finance? Is it possible that because Bob or Jane approved the message, Exchange Online saw them as the sender and thus allowed it through? I checked the internet headers and the only sender is Ed.


Exchange Server Management
Exchange Server Management
Exchange Server: A family of Microsoft client/server messaging and collaboration software.Management: The act or process of organizing, handling, directing or controlling something.
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  1. KyleXu-MSFT 26,206 Reputation points


    I did the testing in my lab and get a different result which looks more logical:

    Group1 :


    Then Admin sends email to group1, User C.C approve this email:

    User A.A in group1 could receive this email successfully:

    Then Admin receive an email which said cannot send emails to Group2:

    So, if your group configuration are correct, this email will not be accepted by group2. I would suggest you double check about the configuration.

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  2. Alex C 56 Reputation points

    I think I'm set up the same way. Interestingly, when Ed sent the message, he did get a bounceback, but still everyone received it. I can't show or test the actual DLs for privacy reasons, but here's the setup. I think it matches your test setup.