Plenty has been written about Shortmail, the "Twitter for e-mail" startup from Baltimore-based 410 Labs, but almost all of it is the usual journalism-by-press-release. Shortmail is one of the few web apps I can remember adopting and finding genuinely useful in the past couple of years, so it deserves a more thorough accounting. Plus, I recently had the chance to talk to Jonathan Julian, one of the developers at 410 labs, and he explained to me some of the logic of Shortmail that I had been missing.

First, a disclaimer: Shortmail is one of those things that you have to try out for a while to really grok, and it's not for everyone.

Use Case: Public-Facing E-mail

I have no idea how many people make their e-mail address available publicly, so that strangers can send them messages. But I suspect that almost every professional who wants to be reachable does. The proliferation of contact forms on the Web suggests that companies and individuals want to be reachable, but also want a way to filter out the spam.

Shortmail seems almost custom-tailored for this application. In the same way that anyone who is desperate to reach you could send you an @reply on Twitter, Shortmail provides a channel through which anyone can send you a note—but only up to 500 characters in length. It helps that your Shortmail account is by default your Twitter handle @ shormail.com.

As someone who often gets much longer notes from complete strangers, I thought at first this would be a problem. But it turns out that if someone hasn't made their case in the first 500 characters, I'm not interested anyway. And because Shortmail is a separate channel from my personal email address, it's an automatic filter for an entire class of mail: First-time connections.

Use Case: Concision

Obviously, replying to people in an environment that demands I use only 500 words is its own time saver. Shortmail provides the perfect excuse for keeping everything brief. It's the psychology of exchanging messages with an @shortmail.com account, as much as anything, that gives everyone permission to be direct.

Use Case: The Get Things Done Approach to E-mail

I've always thought that adherents to the Inbox Zero faith—which demands that you file or reply to every e-mail you get, as soon as you read it—were a special breed. My own inbox is a confusing mess. (Of course, there's evidence that there's nothing wrong with neglecting the organization of your e-mail.)

Shortmail's interface has none of the advanced organizational features of most other Web mail providers, and at first I found it balky. Then I spoke with Jonathan Julian, one of the developers who works on Shortmail, and he said this is intentional.

In Shortmail, messages are viewed one at a time or in threads grouped solely by whom you're having the conversation with (rather than by particular chains of e-mails). You archive one at a time. It forces you to make simple binary decisions about every e-mail: Respond or banish. The result is that, despite my tendencies, my Shortmail inbox is at zero.

Shortmail apparently works really well with the stripped-down Mac OS email client Sparrow, though I haven't tried it. There's also an iOS client. Shortmail supports both IMAP and POP, so you can feed it into any desktop email client.

Use Case: "Open" Conversations

The shortmail team continues to add nifty features to their service, like contact forms for your website, markdown, and what the developers call open conversations. It's e-mail in public.

In general, Shortmail feels like a niche solution that might take off, or it might not. That's fine—I've been wondering for some time when we'll see more development firms take the 37Signals route to success rather than the Facebook route. That is, building a service that works for a subset of passionate users, instead of trying to become huge and all consuming and, let's face it, kind of awful.

Thanks to email management startup Tout, I just got access to an analytics dashboard that includes an array of deftly visualized statistics covering my use of email in 2011. And you can too, right here. If you're wondering what you'll get in exchange for giving Tout access to every email you sent and received in the past year, here's a sample dashboard, so you can get a feel for the results. (They promise they don't read or store any of it.)

The main thing I learned is that quantifying the volume of emails I send and receive every day helps explain why I always feel helpless in the face of my ever-expanding inbox. Here's the bottom line:

• I received nearly 30,000 emails in 2011, an average of 82 a day.

• I sent 7,200 emails, an average of 20 a day.

Tout isn't just a dashboard. The company's real business is a system that allows sales and PR folk to create templates, track the performance of the emails they send, etc. It's designed to make people more productive with email, which remains stubbornly important despite everyone's attempts to kill it.

One of the most important things my Tout dashboard taught me is that a lot of the email I receive is essentially me spamming myself -- alerts, newsletters and the like. Seeing the numbers laid out like this, I wonder: what's my time really worth?

Friends don't let friends use folders, says IBM Research

If you're the type to meticulously file your emails in various folders in your client, stop, says a new study from IBM Research. By analyzing 345 users' 85,000 episodes of digging through old emails in search of the one they needed, researchers discovered that those who did no email organizing at all found them faster than those who filed them in folders.

By using search, the non-organizers were able to find the email they needed just as easily as filers. They also didn't have to spend any time filing email in folders, putting them ahead overall.

Other results from the study (pdf) pointed to ways in which existing email clients might be improved. For example, scrolling was a big part of how users found emails, even after they searched for them, yet scrolling isn't supported by gmail, which uses pagination instead.

The study also suggested that if you want to keep your (and others') email inboxes tidy, you should do everything you can to keep your conversations in existing threads. It's an automatic mechanism for grouping a conversation, after all.

The researchers involved found threading so useful that they even suggested a way it could be improved, which they call "superthreading."

How might we impose higher-level intrinsic organization on email? One possibility is to re-organize the inbox according to 'semantic topics'. One could use clustering techniques from machine learning to organize the inbox into 'superthreads' by combining multiple threads with overlapping topics, using techniques similar to [8].

Superthreading would automatically group every conversation you had with a colleague about a particular project, no matter how many exchanges it was spread across.