Dave Bermingham shows how to send e-mail alerts based on Perfmon counter values:
The first thing that you need to do is write a Powershell script that when run can send an email. While researching this I discovered many ways to accomplish this task, so what I’m about to show you is just one way, but feel free to experiment and use what is right for your environment.
In my lab I do not run my own SMTP server, so I had to write a script that could leverage my Gmail account. You will see in my Powershell script the password to the email account that authenticates to the SMTP server is in plain text. If you are concerned that someone may have access to your script and discover your password then you will want to encrypt your credentials. Gmail requires and SSL connection so your password should be safe on the wire, just like any other email client.
It’s an interesting use of built-in Windows functionality to perform alerting.