Email users are only six mouse-clicks away from anyone else in cyberspace, a team including two Australian researchers at New York's Columbia University has found.
Drawing on the six degrees of separation theory, the experiment involved more than 60,000 participants in 166 countries who registered online.
Volunteers were asked to begin an email chain to reach 18 "target" people in 13 countries, including Australia.
Each person in the chain was to forward the email to someone they thought would get it closer to the target. Although some message chains died out, researchers found that emails could reach their targets in an average of five to seven steps.