One of the things that is most apparent when you switch to a Mac is the quality of the built-in applications that come with the Mac operating system. It's pure joy to not have to go searching for a calendaring program, since iCal is so full-featured. One that is perplexing, however, is Apple Mail, or Mail.app as the Mac-heads tend to call it.

Apple Mail is beautiful in its simplicity and has some really powerful features like the ability to build Smart Mailboxes, which are effectively folders that have a persistent search criteria populating them. With everything that it has going for it, Apple Mail fails miserably in one very fundamental way: weak keyboard shortcut options, and specifically the ability to file messages to different folders based on keyboard shortcuts.

If you've found yourself stymied by this oversight in Apple Mail, fear not... there is a solution. It's called Mail Act-On.

Mail Act-On allows you to do almost anything you'd want to do with a message or group of messages with a single keystroke. It builds on the fantastic Rules preferences pane in Mail to allow complete flexibility with respect to the action you'd like to perform on a message; anything from flagging messages, coloring them, filing them or automatically replying to them. Literally anything you can create a rule for, you can set up as a keystroke action.

This functionality is so well thought-through and implemented that almost instantly you forget that you are using an add-on. This is something that simply should exist in Apple Mail, but for now, you can just install the free Mail Act-On add-on and rejoice at your newfound power.