The holidays weren’t merry or bright for the U.S. Postal Service.

The nation’s mail delivery service lost $3.3 billion in its first quarter, which runs from Oct. 1 through Dec. 31 and encompasses the holiday shopping and shipping season.

Total mail volume reached 43.7 billion pieces, a 6 percent decrease from the previous year, the USPS said. Revenue on first-class and standard mail dropped 3.7 percent, to $650 million.

Despite slumping mail volume, the Postal Service’s shipping services improved, generating $2.8 billion for the quarter, a 7 percent year-to-year climb.

The rising cost of gasoline also affected revenue and forced the USPS to spend 6.3 percent more on transportation expenses in its first quarter. To reduce overall costs, the Postal Service cut 8 million work hours, helping to cut pay and benefits expenses by $180 million, or 1.4 percent.

Joe Corbett, the USPS chief financial officer, warned again that the Postal Service will probably default on retirement and health benefits payments this year unless Congress changes the pay formulas.

A coalition of businesses tied to the mailing industry once again called on lawmakers to quickly pass postal reform legislation.

“We have a Postal Service that essentially is living from paycheck to paycheck, which is a very risky proposition for the American economy and the 8 million private sector workers whose jobs rely on the mail,” said Art Sackler, head of the Coalition for a 21st Century Postal Service. “A great financial quarter isn’t going to save the Postal Service, but a terrible financial quarter could sink it. That’s why Congress needs to pass postal reform legislation now.”