Manned flight was a new technology. The proposal to build a new SMTP with [...] requires <i>abandoning</i> SMTP as it is now and convincing everyone to switch.<p>If the Wright Brothers wanted to eliminate auto accidents by flying, anyone at the time could have told them they were doomed to failure, and history would have proven them right, even though air travel is safer than road travel. That&#x27;s because getting people to stop using cars isn&#x27;t simply a matter of inventing an airplane.