Come August 1, the bankrupt and deeply in debt US Postal Service means to stop delivering first-class mail on Saturdays and save a projected $2 billion a year.

It will still deliver packages six days a week.

While e-mail and texting killed its letter business, e-commerce has thrown the agency founded by Benjamin Franklin a lifeline. Its posties trudge the so-called "last mile" to the consumer's door with parcels sent through FedEx and UPS.

The USPS says package delivery has increased 14% since 2010. Mail, other than junk mail, is negligible.

After the ax falls this summer it will still deliver mail to post office postboxes on Saturday.

Early announcement of the plan is supposed to give customers time to adjust but the agency has yet to get congressional approval for eliminating Saturday mail delivery, which is legally mandated.

According to USPS research, seven in 10 Americans support the move if it means reducing the agency's crippling costs. It originally meant to eliminate all deliveries on Saturday but met resistance.

"The Postal Service is advancing an important new approach to delivery that reflects the strong growth of our package business and responds to the financial realities resulting from America's changing mailing habits," Postmaster General Patrick Donahoe said in a statement. "We developed this approach by working with our customers to understand their delivery needs and by identifying creative ways to generate significant cost savings."

The USPS lost a record $15.9 billion its last fiscal year ending September 30 and also reached its borrowing limit. The biggest drain on its finances - amounting to $11.1 billion last year - comes mostly from the unique requirement that it pre-fund retiree health benefits years into the future. The USPS wants Congress to relieve it of the $5.5 billion-a-year burden but so far its pleas for long-term financial stability have been ignored.

The USPS is otherwise restructuring by closing or consolidating branch offices and cutting hours at post offices.

Fredric Rolando, president of the National Association of Letter Carriers, an opponent of the move, says ending Saturday delivery "would be particularly harmful to small businesses, rural communities, the elderly, the disabled and others who depend on Saturday delivery for commerce and communication."