The Exchange Server User Monitor (ExMon) RPC data indicates that the user '{3}' is causing high load on this server. Restrictions ...

The Exchange Server User Monitor (ExMon) RPC data indicates that the user '{3}' is causing high load on this server. Restrictions issued by this user account for {0}% of the RPC processor usage. The 'Restrict' operation can cause view creation on the server and may result in a significant impact to end user performance. Consider upgrading this user to Outlook cached mode.