I got this error on Exchange 2010 console:
The attempt to connect to http://xxxxxxxxx.local/Powershell user ‘Kerberos’ authentication failed: Connecting to remote server failed with the following error message: The WS-Management service cannot process the request. The system load quota of 1000 requests per 2 seconds has been exceeded. Send future requests at a slower rate or raise the quota for this user. The next request from this user will not be approved for at least X milliseconds.
Start --> CMD as Administrator --> iisreset