message trace

Question

Hi All,

One of my users asked me to remove him from the distribution list (DL) so that he no longer receives those emails. I have removed the user from the DL, but he is still receiving emails. It is possible that the user is receiving emails from another DL, or that he is added as a BCC, which I am unsure of. How can I trace which DL or if the user is in BCC to identify where the emails are coming from? Is it possible to trace this using the message ID or subject? Please guide me.

Answer 1

Hi,@Glenn Maxwell

Thanks for posting your question in the Microsoft Q&A forum.

**1.**How can I trace which DL or if the user is in BCC to identify where the emails are coming from?

You can use message trace to track which DL sent the email, but there is no way to determine if the user is in the BCC.

The query results are as follows to confirm which DL it is by the sender's address.

The only way to determine if a user is in BCC is to look at the headers of the message.

**2.**Is it possible to trace this using the message ID or subject?

The message ID or subjec does not enable tracking of whether the user is BCC or not. When you use Message Trace, whether you are the recipient or BCC, it is the recipient on the Message Trace result.

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Answer 2

Check if the user is part of a nested group. Even if they were removed from the direct distribution list, they may still receive emails if another group they belong to is a member of the main DL.

To identify this, you can analyze the group hierarchy and its nested memberships. You can verify all groups and their nested members using this script: https://m365scripts.com/exchange-online/export-office-365-nested-distribution-group-members-using-powershell/

Additionally, if you suspect the user is receiving emails via BCC, you can check the message trace using the Message ID or Subject to see the exact recipient path.