To prevent emails from accidentally getting sent from a local development environment, I use a two part scheme. First, for Drupal, I turn on the devel module and then add the following to my settings.php:
"Module provides Drupal installation with various security hardening options. This lets your mitigate the risks of exploitation of different web application vulnerabilities."
Make spam go away! This is a great service that is free for a low traffic site. A great anti-spam solution for Drupal! Also check out Honeypot and the Bad Behavior module.