Alto is like an intern who sorts your email, separating the e-wheat from the e-chaff. This free browser-based service organizes mail into virtual stacks, not unlike the way you might sort physical junk mail into piles on your desk.

Developed by AOL, Alto works with the most popular email services, including Gmail, iCloud, Yahoo, and, of course, AOL. And you can use it with multiple accounts, making this a great way to manage several inboxes under one roof.

Once you sign in, Alto sifts through your inbox and sorts your messages into a handful of existing stacks: Daily Deals, Social Notifications, Photos, Attachments, and so on. You can create additional stacks as well, and once you direct an email to it, all future messages from that source will automatically land there. Thus, you could have a “client” stack, “boss” stack, “widget project” stack, and the like.

Alto’s pretty interface features a scrolling inbox on the left side that lets you preview each message without actually clicking it. If you mouse over an individual email, you’ll see one-click icons for Delete, Snooze, and Star. The Snooze option is particularly great for business users: It lets you temporarily archive an email until a later time, thus getting it out of your inbox but returning it to the top when it’s more convenient for you to deal with it.

Alto rocks. But it’s currently a private beta, meaning you need to request an invitation to try it out. The good news is that your invitation should arrive within about 24 hours, at least based on my recent experience.

Note: The Download button takes you to the vendor's site, where you can sign up to join the private beta of this Web service.