Merlin Mann, 43 Folders productivity bodhisattva, offers some tips 
on using Mail Act-on to increase productivity and handle the hackwork of filing and processing your emails.
He shows you how to make several clever Mail Act-on rules that interact with Mail’s smart folders and MailTags to create a workflow that works for him.
He also offers a sneaky tip for remapping the Caps Lock key to the Control key function. No more weirdly bent pinkies for him!
As Merlin says,
I’m really just scratching the surface on what you can do with Mail Act-On — I’m sure there are power users out there who are doing much sexier stuff with it — but I wanted to make sure people know that this is most definitely not just for geeks and high-volume email users. In my opinion, this is functionality that should (and eventually will) be included as a stock feature in Mail.app.
