Email remains the poster child (given its age, perhaps that should be poster grandparent) for how a lightweight federated communications protocol can service needs from micro to mega.<p>For comparison: the sidelining of XMPP by corporate interests was awfully disappointing; the centralisation of social networking feeds is downright heartbreaking.  But none of that should put us off trying and trying again.  Everyone with an interest in how the Internet protocol stack works in context should try running their own mail service, it&#x27;s a fantastic and low-cost way to gain insight.