A customer I was working with last week had trouble tracking down all the places that an email address was placed in an allow list–across multiple transport rules and other filter policies.
I created a tool just for this back in 2018, but it got lost in the TechNet Gallery decommission. I’ve updated it and placed it on the PowerShell Gallery.
I also updated verbiage and parameter names, consistent with our unconscious bias training, as well as some of the formatting and search syntax. You can find tool here now: https://www.powershellgallery.com/packages/Get-AllowAndBlockListings/