U.S. Regulators Reviewing USPS Five-day Mail Delivery Plans: U.S. Postal Service ( USPS ), which recorded a $16B loss last year and expects to lose around $7.5B this financial year, believes reducing letter delivery services by a day per week could save $2B a year. The Postal Service has been bound by U.S. federal appropriations legislation to provide six-day-a-week mail delivery since the early 1980s. However, after last year saw Congress failing to pass reforms including a move to five-day-a-week mail delivery, Postmaster General Patrick Donahoe ordered a reinterpretation of the law.