The new Get-MessageTraceV2 cmdlet can fetch 90 days of message trace data, which means that we can check for inactive distribution lists using data for the last 90 days instead of being constrained to the last 10 days. Distribution lists are still important to Exchange Online and Microsoft 365, and it’s good to know which distribution lists are in active use (and how much traffic they get) and which are not. All done with PowerShell.
Microsoft announced the GA for the new message tracing feature on June 3. The old code will be deprecated in September 2025, so it’s time to update any PowerShell scripts that use the Get-MessageTrace or Get-MessageTraceDetail cmdlets. Upgrading is easy and shouldn’t take too long, once you find the time to do the work.
This article describes how to use PowerShell to extract and analyze Exchange Online message trace data to figure out the volume of traffic to outbound domains and from inbound domains. You might think that this is the same information as available in the Exchange admin center mail flow report, but it’s not. Once again, the value of PowerShell in retrieving and using data is evident.
A recent correspondent asked how to find inactive distribution lists in Exchange Online. We didn’t have a good answer in the book, so here’s some PowerShell code to do the trick.
