Believe it or not, email used to actually be a productivity-enhancing tool -- although by now you're probably drowning in a deluge of spam, sales pitches, and social media notifications. MailHub is a plugin for Apple's Mail that aims to help you quickly sort through the useless stuff, and focus on the messages that are truly important. Learning to use MailHub's many options takes some effort, but you'll learn to speed through, deleting, filing, and setting reminders with an arsenal of keyboard shortcuts.

MailHub installs itself as a toolbar that sits atop your Mail window.  Mouse and trackpad users can quickly click toolbar items to file messages, create  reminders, and add additional mailboxes. All of these capabilities are backed by keyboard shortcuts, which is where MailHub really flies.

MailHub's neatest trick is that it's predictive. The first time you run it, MailHub indexes your mailboxes, figuring out where you tend to put certain kinds of messages. Then as you work your way through emails, MailHub's File Message command will offer to stash your message in the folder it assumes you'll move it to. There's even an option to automatically file your replies alongside the original message.

Filing works surprisingly well right off the bat, but MailHub's powers of prediction also improve the more you use it. And you can always file to a different location by typing a few letters of the mailbox name. When filing messages, MailHub allows you to act on the selected message, a message's entire thread, or all messages from that sender. You can set one of the options to be the default, but switching between the three modes is simple for flexible organizing on a case-by-case basis.

Of course, MailHub's mailbox-centric approach works best if you're a mailbox person. Users who manage their email with a limited set of mailboxes, or more modern Gmail-style tag systems may find the plugin less useful than if you're a compulsive filer with a hierarchy of folders.

MailHub also includes a handy pop-up pane that lets you know where messages have gone off too every time it performs an action. It's a useful failsafe as you're getting used to filing mail with MailHub, but we wish there were more configuration options. Growl users can switch to Growl notifications, or none at all.

If your to-dos live in Reminders, MailHub offers a simple and powerful way to turn email messages into tasks. With a message selected, click the Reminder button, and MailHub pops up a pane where you can set parameters for your reminder. Choose a date and time with the calendar, or use the handy buttons to push something off until later today, tomorrow, next week, or next month. MailHub even auto-populates the description field with the text of the source email, so you can easily access relevant information without leaving Reminders.

The bottom line. With its predictive filing and extensive keyboard shortcuts, MailHub might actually make email productive again.