Fresh off the nation's biggest holiday shopping season in years, President Trump went postal on Amazon, suggesting on Twitter the online retailer is taking advantage of the federal government's beleaguered mail service.

Amazon and its founder, Jeff Bezos, have been the targets of Trump's tweets in the past, but his Friday morning barrage did collateral damage to the U.S. Postal Service, which Trump said ought to charge more to deliver the online giant's packages.

“Why is the United States Post Office, which is losing many billions of dollars a year, while charging Amazon and others so little to deliver their packages, making Amazon richer and the Post Office dumber and poorer? Should be charging MUCH MORE!” Trump tweeted.

His comment seems to be in response to a “Fox & Friends” segment about tech trends in the new year which was aired Friday morning. The piece focused on Amazon making shopping easier for its customers.

Following the president’s comments, Amazon shares quickly reversed course in premarketing trading.

This isn’t the first time Trump’s used Twitter to taunt Amazon.

TRUMP ATTACKS AMAZON ON TWITTER AGAIN, SAYS IT'S 'DOING GREAT DAMAGE' TO RETAILERS

The president has a long-standing feud with the online retailer and especially its founder.

Bezos also owns The Washington Post, a frequent critic of the president.

On July 23 Trump tweeted:

“It's hard to read the Failing New York Times or the Amazon Washington Post because every story/opinion, even if should be positive, is bad!”

Trump has also claimed at times that Amazon is using financial losses at the Washington newspaper to lower its tax bill.

Amazon does not own The Washington Post.

The president has also suggested Amazon doesn’t pay taxes. And in August, accused the company of “doing great damage to tax paying retailers. Towns, cities and states throughout the U.S. are being hurt – many jobs being lost!”

PRESIDENT TRUMP ATTACKS AMAZON ON TWITTER, SAYS IT DOESN'T PAY 'INTERNET TAXES'

Despite the presidential digs, it’s been a pretty good year for Bezos.

The 53-year-old business mogul saw his net worth climb to more than $100 billion in November after shares of Amazon surged.

As for the U.S. postal service, financial problems have plagued it for years. In September, the USPS reported a net loss of $2.1 billion in the third quarter. It marks the 11th consecutive year that the USPS has lost money. In the last decade, it’s posted $65.1 billion in losses.

“Our financial situation is serious, but solvable,” USPS CEO Megan Brennan said in September. “The continuation of aggressive management actions, and legislative and regulatory reform, will return us to financial stability and enable the Postal Service to maintain the long-term affordability of mail, invest in America’s mailing and shipping industry, and best serve the American public.”

Prospects of legislative reform seemed more attainable earlier this year. The House Committee on Oversight and Government Reform voted in March to advance a bailout bill called the Postal Reform Act of 2017. It was sponsored by former Rep. Jason Chaffetz, who has since resigned.

He is currently a Fox News contributor.