The U.S. Postal Service is marching towards a more "centralized delivery," where residents pick up their own mail from clusters of mail boxes located in their neighborhood. Local postmasters are sending hundreds of letters to fast-growing communities, warning that cluster boxes will be the way mail will be delivered to new developments.
Delivering mail is the agency's largest fixed cost—$30 billion. Ending such door deliveries would save $4.5 billion a year. That's more than the $3 billion it would have saved from ending Saturday mail service, according to government reports.