This post will let you resolve the issue of CPU usage which increases to 99% after installing Microsoft Dynamics CRM Email Router.
To resolve this go to the services and find Microsoft CRM Email Router service and follow below steps:
1. Go to the properties of the router service and then click on the log on tab
2. You will notice that router service is running under Local System account. Change this to other account. Click on apply and close the pop up by clicking OK.
3. Now open the task manager and you will notice that CPU starts getting down.