Exmon

The Microsoft Exchange Server User Monitor (ExMon) tool enables administrators to
view and evaluate individual users' usage and experience with Microsoft Exchange
Server. With this tool, administrators can gather real-time data that helps them better
understand current client usage patterns and plan for future use.

Using ExMon, administrators can view the following:
  Show the RPC data based on the user
  Show the RPC data based on the RPC Operation
  Show the RPC data based on the specific application
  Show the RPC data based on the Admin Client Type
  Show the RPC data in the Raw form
  Show the RPC data in the Admin Raw form
  Show the RPC data in the Task by client Type
  Show the RPC data in the Task raw

Within each view, the user can drill down to get additional information on:
  Microsoft Office Outlook® versions and mode
  Client monitoring data
  Resource use, such as:
  CPU usage
  Server-side processor latency
  Network bytes
  RPC Operations, components and Action

https://www.microsoft.com/en-us/download/details.aspx?id=51101