Hi,
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Based on your description. You may need a shared mailbox.
In Exchange Admin Center, click Recipients->Mailboxes->Add a shared mailbox
After that, you can delegate permissions to users. If you want to allow users who share this mailbox to view the mailbox's inbox, add the users to the "full access".
Then you can add the shared mailbox to users' Outlook. For details you can refer to:create a shared mailbox and Open and use a shared mailbox in Outlook .
Please be free to contact us for any updates. And if this helps, don't forget to mark it as an answer. Thanks for your understanding!