Is it possible to produce a report on external communications taken place to/from domains on the federated "allowed" domain list in skype for business online?
eg. Show me a report from the last 3 months where an external user has communicated with an internal user via federated domains.
I'm not aware of any way to do this, but I'm subscribing in case someone does know how :)
Perhaps look into the data returned by Get-CsUserSession?