Starting in Splunk 6.1, this ability is built into the product. Edit your search and look under the "Click to edit email action" link in the "Alert Actions" section. It's a simple check box you can uncheck. It's in the picture in step 4.
Instead of making any changes to the python script. you can use the following if you need an email everytime the search is executed.
You can disable the Email alert(uncheck the checkbox for Email) and add the following to your Splunk search query -
if it throws any error then remove the server info from the search : |sendemail to="
If the alert condition is met then the
A quick search turned up the following question that someone asked earlier:
basically, you can alter the python script that sends out the emails to suit your needs.