Setting up a shared mailbox in Microsoft Outlook is easy to do and has many benefits for some users. Here's how you can make it happen.

Before you can set up a shared mailbox in Outlook, you’ll need to create one. This requires a Microsoft 365 Business Standard or above subscription with the Exchange Online Service.

1) open shared mailbox in outlook. Create rule that when new email received, forward the email as attachment to all the recipients (best practice would be to create an AD group for this) ...

I noticed that the shared mailboxes all only had "outlook on the web" and "exchange web services" checked under the "manage email apps" setting.