Are you curious about the hard stats of messages running around your organization?
Try this one in powershell on your hub transport server:
get-messagetrackinglog -start “mm/dd/yyyy hh:mm:ss” -end “mm/dd/yyyy hh:mm:ss” -eventid “send” -resultsize 9999999 | measure-object
This will pull stats for messages that were “sent”.  To pull the number of messages received, change the “eventid” parameter to “receive.”
