We have all had our fill of spam. Nearly every computer user on the planet will agree that it is a dreadful nuisance; most of us will have noticed that it is also becoming rapidly more offensive. At home, most of us can just empty our spam traps periodically without even bothering to look at them.

If we delete a few genuine messages – known in the trade as ‘false positives’ – it is not the end of the world. But in business, it is a different matter. For a law firm, it is unthinkable that important messages from clients get deleted accidentally.