I’ve had a brief fling with Taglocity, an Outlook add-in for tagging email, contacts, and tasks. You can of course already tag messages in Outlook using categories, and I do, but rarely, just as I’ve rarely used labels in Gmail. For me at least, tagging is most interesting and useful when it is social.

Consider, for example, the recent interaction around the publicdata tag in del.icio.us. I’m continuing to see new items show up in the global bucket, /tag/publicdata. Occasionally I add one of these to the list I’m curating in my private bucket, /judell/publicdata. There, I can see at a glance which of the items I’ve collected are of interest to others, and to how many others. Focusing on the Bureau of Justice crime data I’ve been using lately, I can see who else tagged it, I can observe the historical interest in that URL back to 2004, and I can notice that it was most recently tagged by somebody at Many Eyes. I can then compare the list that’s being curated by Many Eyes to the list that I’m curating.

So here’s the question: Can these effects occur in email? In theory they can, and Taglocity lays the foundation with a feature called traveling tags. This is actually an idea that I discussed long ago in my book Practical Internet Groupware, where I suggested that keywords could be passed in SMTP headers, or in XML packets carried in message bodies. From the Taglocity FAQ:

Taglocity has a number of ways of transferring the tags you have assigned to an outgoing message to the recipient. These include using the SMTP Keyword header and something called a ‘Tagline’. A Tagline is a footer that includes the text ‘Tags:’. The Tagline is very simple but will work on any device and mail relay, as it is placed within the message content.

In my experiments I didn’t find any evidence of the SMTP method, but maybe that got stripped out by an intermediate relay. The tagline wouldn’t be the nicest thing to have to parse mechanically: 

<p class=3DMsoNormal><span style=3D'font-size:8.0pt;font-family:"Arial","sa=
ns-serif";
color:#8C8C8C'><a href=3D"http://www.Taglocity.com">Taglocity</a> Tags: tag=
ging,
socialsoftware</span><span style=3D'font-size:12.0pt;font-family:"Times New=
 Roman","serif"'><o:p></o:p></span></p>

But it’s doable, and there may be an option for including a more well-structured packet.

These are just technical details though. The real question is: What kind of tag-related social dynamics are even possible in email? I guess that’s something you could only find out by trading tags with other people for a while.

In an internal email thread on this topic, one person noted:

I wonder if there’s both a public tagspace and a private tagspace? What if I want to tag a thread as “readlater” or “notmyproblem”… does everyone have to suffer my personal categorization?

I investigated, and found that there is a notion of public and private tagging. It works on a per-tag basis, though, unlike del.icio.us’ per-item privacy, so apparently you’d need to develop a private vocabulary that included no tags you’d want to use in public.

In an another message on that internal thread, someone noted the obvious problem of critical mass. The social effects in del.icio.us are a function of scale. Is departmental or even corporate scale sufficient to sustain those effects? Even when it is, as I’ve heard is true for IBM’s internal use of Dogear, can the social effects of that kind of web application be usefully translated to the email environment?

I don’t know the answer, but I’d love to hear from folks who are actively using Taglocity (or equivalents, if they exist) about what works or doesn’t, and why or why not.