Creating a Microsoft 365 Retention Policy for Shared Mailboxes

shared mailboxes and microsoft 365 retention policies

After being asked whether licenses are needed to include shared mailboxes in Microsoft 365 retention policies, I investigated and found that licenses are not. This led to a consideration of the steps needed to create a special retention policy for shared mailboxes (with PowerShell, naturally) and how to avoid retention setting collisions with other policies. All explained in detail here.