Businesses could soon be able to buy direct access to a customer's mailbox--and your direct mailings may well get costlier, too.

The U.S. Postal Service  is on an "unsustainable financial path," accumulating $69 billion in total net losses over the past 12 years, and in dire need of adopting new revenue streams, according to a new report from the Treasury Department. One way to boost revenue is to capitalize on the post office's mailbox monopoly and license access to the mailboxes of nearly 159 million households and businesses in the U.S. To this day, it is a federal crime for anyone other than a postal service worker to deliver correspondence to a person's mailbox.

"The USPS's exclusive access rights to mailboxes protect customers from theft, obstruction, fraud, and other mail-related criminal activity while protecting the personal privacy of consumers," reads the report, noting it also provides an advantage to USPS for the delivery of parcels small enough to fit in a mailbox. As other delivery services grow, "it is reasonable to expect a willingness to pay for access to USPS mailboxes," the report continues. "By franchising the mailbox, the USPS could expand its revenue and income opportunities without necessitating any change to its current mail products."

The report doesn't disclose how the licensing process would work, what USPS could charge for it, or how much revenue it might bring in. It is one of several recommendations outlined in the document, along with reducing labor costs by partnering with third-party providers for certain tasks and issuing hunting and fishing licenses at the Post Office.

Another recommendation calls to reclassify mail by purpose instead of type. Think business or commercial mail as opposed to letter or package. The report suggests USPS should be able to command higher prices for purely commercial mail, such as direct marketing leaflets.

President Donald Trump has long advocated that USPS should increase the rates it charges e-commerce companies like Amazon. However, the government analysis states that increasing package fees alone will "fail as a competitive strategy" given the higher costs associated with their delivery. Instead, the report calls for a multi-pronged approach that could also improve USPS data tracking systems, which will allow it to gather business intelligence on customer preferences and offer targeted pricing.