Something remarkable has happened to the medium of email. From being simply a convenient technology for sending messages to other people, it has morphed into something much more complex and uncertain. The symptoms of this are not always obvious, but a case this week reminds us that the world has changed without many people noticing.

Exhibit number one, this week’s strange case of a leaked email said to have been composed but not sent by an official close to the heart of the UK government, allegedly expressing doubts about the honesty of another senior government official in his relation to a high-profile police investigation.

The email was apparently never sent, but was stored on a PC and subsequently found by officers investigating a case known to an increasingly wearied UK public as the “cash for honours” investigation. It has now, magically, turned up in the public domain just in time to cause trouble on a scale that turns the amplifier up to eleven.

What matters here is not the increasingly tedious detail of the case, but the fact that an email is at the heart of it at all. There is nothing new in emails having an effect on public investigations, of course, but there is something rather special about this email that goes beyond the fact of its contentious content.

Baring a conjecture, that an official wrote the email at all suggests that she did so knowing it might eventually be found. We can’t be certain of this, but it is possible that it was written not to communicate information or a point of view, but as a future defence should events take a negative turn. Which, funnily enough, they now have.

She could have written a paper memo, but she didn’t. Memos can be lost, destroyed, mislaid, and disappear according to the well-worn principle of plausible deniability. Emails can’t. Making an email disappear is very difficult, something we might also hypothesise, the official would have realised.

Email can be deleted, of course, but only by removing not only the copy on the sender’s hard disk, but every backup too. Then the fact that these copies have been deleted is also logged, as is any subsequent act of log deletion or timestamp tampering. For a government or organisation to remove all trace of an email is a heavy undertaking, requiring organised lying and connivance on a scale that is possible but unlikely. And that’s just for the emails they know about.

Email has become the most leakable form of information yet invented even though most people persist in seeing it as merely a communication tool. It is much more dangerous than that, hard to control, and even harder to deny. It can appear from nowhere and change destinies in a matter of kilobytes. We now know it doesn’t even have to be sent to anyone because the mere fact it *could* have been sent imbues it with significance.

All over the land new employees are drilled on the art of email, when to write it, what to say and not to say, and the legal consequences of ignoring the rules. As the clever realise, there are hidden rules for those who can reach out and grasp the power not just of information itself, but of the IT systems and procedures that underlie it and make the modern organisation possible. Such systems can aid the truth, but can also be used to create a version of events so as to oppress its frank and open telling.

Communication is a always version of events, no matter when it was committed to record or by whom, or for what reason. But make no mistake - leaving aside this email scandal-in-the-making for a minute - the possibilities of email to manipulate and incriminate in ways not always apparent to the unsavvy are there for all to see. It leaves a trace of people’s actions long after they have gone, but only the naïve would see it as an innocent account. The lure of dissembly is too tempting.