A federal judge yesterday dismissed a Justice Department attempt to block the U.S. Postal Service from beginning its controversial electronic mail service, clearing the way for the plan to begin on schedule Monday.

The Justice Department immediately asked a panel of judges from the U.S. Court of Appeals for the District of Columbia to stop the introduction of the electronic mail system. It wasn't clear when the panel would rule.

The case was dismissed by U.S. District Court Judge Thomas A. Flannery, who ruled on the basis of whether he had the statutory authority to hear the case, not on the its merits. Flannery said that, under law, any decision made by the Postal Service Board of Governors--in this case to proceed with electronic mail--must be taken to an appellate court.

The Justice Department had sought a temporary restraining order and a preliminary injunction against start-up of the service.

"I am of the opinion this court does not have jurisdiction over this case," Flannery said after a hastily called one-hour hearing. "Therefore, I'm dismissing this case for lack of jurisdiction."

Postmaster General William F. Bolger said the electronic mail service will begin as scheduled on Monday.

The Justice Department had filed late Wednesday a suit claiming that the postal service violated the Postal Reorganization Act of 1970 by failing to have a hearing by the independent Postal Rate Commission before starting the service.

The suit was the latest of several attempts during the past three years to stop the system, called E-COM, which is one of the Postal Service's highest priority projects. The Justice and Commerce departments and private telecommunications firms have opposed E-COM because they said the service unfairly prohibits private industry from entering the electronic message-delivery business.

The rate commission earlier recommended an experimental electronic mail service, but the D.C. appeals court last May said the commission didn't have the authority to determine whether the service was experimental or permanent. The rate commission then began expedited hearings on whether E-COM should be permanent, but the Postal Service refused to participate, saying the commission didn't have the authority to determine the issue, the lawsuit said.

The new hearings were suspended on Dec. 3 because the Postal Service refused to participate and plans were made to go ahead with E-COM anyway, the lawsuit said.

Postal Service attorney Ben Heineman said in court yesterday that the lawsuit was "a near-frivolous suit brought in the wrong court at the wrong time . . . " and the Postal Service had already engaged in a year of administrative proceedings producing 12,000 pages of testimony when the rate commission approved the experimental service.

The Postal Service interpreted the May appellate court's decision to mean the judges approved the start of electronic mail but only disputed the rate commission's authority to make it experimental, Heineman said. The postal board of governors had the authority to determine the duration of the system and they approved a permanent one, Heineman said.

In addition, Heineman said any dispute about a decision by the governors must be taken to the appellate court.

However, the Justice Department contended in its suit that the May appellate court's decision meant new hearings had to be held on establishing a permanent electronic system. The postal governors can only act on the recommendation of the rate commission and the commission never decided on a permanent system, Justice Department attorney Stanley Gorinson said.