USPS lost $3.9 billion in fiscal year 2018, according to a new report from the Task Force on the United States Postal System.

The task force made several recommendations in its report on how USPS could recoup losses.

One tactic could be " franchising the mailbox" — charging private companies to allow deliveries to individuals' mailboxes.

You may have never thought of it, but there's only one shipping company that can leave deliveries in your mailbox, rather than just on your doorstep — the United States Postal Service.

And the USPS is famously not doing so well. It's doing so badly, in fact, that President Donald Trump personally urged the federal agency to up delivery prices on the gargantuan online retailer Amazon.

The USPS lost $3.9 billion in fiscal year 2018, according to a December 4 report from the Task Force on the United States Postal System. Its cumulative losses are nearing $70 billion. As the report said, "the shift toward digital correspondence and the corresponding effect of declining mail volumes has led to significant net losses."

A larger contributor to USPS' woes is a 2006 law passed under President George W. Bush surrounding prefunding retirement benefits. That law required the USPS to determine how much it would spend on pension over the next 75 years and quickly build up a fund to cover all of it. According to USPS' Inspector General, the new requirement to prefund retiree benefits accounted for $54.8 billion of the agency's $62.4 billion loss incurred between 2007 and 2016.

Meanwhile, other package-delivery companies are cleaning up in the e-commerce era. FedEx reported strong earnings last quarter, and UPS upped its profit in the third quarter of 2018 by 20%.

Still, the USPS has one key advantage over those private-delivery companies — access to your mailbox. And the USPS Task Force wrote in its 70-page report that the flailing federal agency should "franchise" your mailbox to delivery companies in order to recoup losses.

"By franchising the mailbox, the USPS could expand its revenue and income opportunities without necessitating any change to its current mail products," the report states.

Read more: Trump has ordered a review of the US Postal Service's prices — and it could force Amazon to raise Prime membership fees

The USPS is presently the only body that is able to lawfully access individual's mailboxes. That "protects customers from theft, obstruction, fraud, and other mail-related criminal activity while protecting the personal privacy of consumers," according to the task force report.

Allowing certain private companies to access one's mailbox to deliver small packages would give the USPS a new revenue stream.

"This could be done by retaining the mailbox monopoly and allowing regulated access, for a fee, to certified private companies," notes the report. "These 'franchisees' would be granted access to the mailbox for the delivery of mail and small parcels."

The task force, headed by Secretary of the Treasury Steven Mnuchin, also recommended in the report that the USPS develops a concept for what its key customers are (particularly those in rural households), expand third-party relations, spin off its package-delivery business, and other measures.