GrowlMailPlus

If you're a Mail.app user, you should definitely give GrowlMailPlus a try as it brings a seamless integration of email notifications with Growl. Unlike the standard GrowlMail that comes along with Growl, which notifies only of new mail arrivals, GrowlMailPlus provides notifications for new emails in a more informative manner, by displaying the subject, sender and even the body of the message.

In addition, you don't have to put up with those pesky spam mails that have a tendency to clog up your inbox. With GrowlMailPlus, spam mails are completely ignored making your email-viewing experience smoother and simpler.

All you need to get started with GrowlMailPlus is the Growl software, which must be installed in order to use this plugin. So, if you're looking for an efficient email-notification software that integrates well with Growl and simplifies your email-viewing experience, this plugin should certainly be on your list of must-haves.