Small script to check for system status.
This script was created to run every minute against my weather sensors and check if they are online... If they are down you will get ONE email notifying you of the device been offline. Once you know of your issue please remove the file created under /tmp called "down" I do this to force my self to check the sensors and systems :P
Please use which ever MTA you would like to use and edit the script to fit your needs.