FedEx Corp. has been “systematically overcharging” customers by billing businesses and government offices at higher residential rates, a company sales executive said in an internal email unsealed in a lawsuit, Bloomberg reported.

“I have brought this to attention of many people over the past five or six years, including more than one managing director, and no action has been taken to address it,” Alan Elam wrote in an email on Aug. 2, 2011. “My belief is that we are choosing not to fix this issue because it is worth so much money to FedEx,” Elam said in a separate email that day.

The emails were unsealed Monday in a class-action lawsuit claiming that FedEx Corp. and FedEx Corporate Services Inc. overcharged commercial and government customers as much as $3 each for millions of packages delivered. The plaintiffs, who claim violations of federal civil racketeering laws, seek three times the amount of the alleged overcharges in their lawsuit.

“We allege that FedEx has and continues to engage in a pattern of intentionally charging its customers residential delivery fees for deliveries to obviously non-residential addresses such as courthouses, government offices and banks,” Steven J. Rosenwasser, a lawyer for the plaintiffs, said in an interview.