GrowlMail is a Apple Mail plugin that posts a Growl notification whenever Mail receives new mail.
Besides being useful in general, this is also an example for implementing Growl support in bundles.
Building requires that you have a valid code signing identity from apple due to Mail.app not loading unsigned code.
Please visit https://bitbucket.org/rudyrichter/growlmail/downloads to download the latest version of GrowlMail