The Postal Service, battered by anthrax attacks that have left two workers dead, others sick and the public nervous about its mail, is turning to Congress for financial help.

Postmaster General John Potter has said the attacks will cost the post office billions of dollars, and estimates of damage and loss of revenues have ranged from $3 billion to $7 billion or more.

"Extraordinary expenditures will be required," Robert Rider, chairman of the Postal Service Board of Governors, said this week. "We strongly believe these costs should not be borne by our customers through increased rates."

Rider said the costs should be considered part of homeland defense, and several lawmakers have said they want to include aid for the Postal Service as part of a new $20 billion package of spending related to terrorism.

President Bush said Tuesday, however, he would veto any spending beyond the $40 billion Congress appropriated after the Sept. 11 airliner hijackings but before the outbreak of mailed anthrax.

Nonetheless, Potter was expected to get a sympathetic audience Thursday before a Senate Appropriations subcommittee.

Deputy Postmaster General John Nolan said Thursday it will be after Jan. 1 before the post office has a firm handle on how much money it needs.

"We don't know exactly the technology we'll be using (to sanitize mail), although we have begun to purchase some, and we're waiting to see the end of the Christmas holiday season to see whether the volume picks back up again," Nolan said on ABC's "Good Morning America." "So I would expect that those final numbers will be available right after the first of the year."

Before the attacks, the post office had expected to finish this fiscal year $1.35 billion in the red and is seeking a rate increase to take effect next year.

But that did not anticipate costs from the hijacking attacks, including damage to post offices and sharp increases in transportation costs because of limits on what mail commercial planes can now carry.

Then the anthrax attacks occurred.

The agency has leased machinery to sanitize the mail, is purchasing other machines and has spent a large amount on testing post offices, buying masks and gloves for workers and on medical care for its staff.

At the same time mail volume, and thus income, dropped sharply. In the four weeks after Sept. 11 there were 6.6 billion fewer mail items than the corresponding period a year ago.

In Bellmawr, N.J., a federal judge closed a postal distribution facility Wednesday after workers complained that they weren't sure it was free of anthrax. A postal workers union said an outside contractor had cleaned the wrong machine after anthrax spores were found on a barcode-sorting device.

Judge Jerome P. Simandle said the facility should remain closed until an arbitrator considers the union's complaints. A worker at the station is being tested for skin anthrax.

Potter and other postal officials met Wednesday with leaders in the mail industry to discuss the agency's future and how to restore confidence in the mail.

Potter announced that Gary Mulloy, president of the advertising firm Advo, donated $250,000 to increase the reward for information leading to whoever sent anthrax in the mail. That reward now stands at $1.25 million.

"The anthrax attacks are changing the way all of us do business," Potter said. He said the business leaders "explored new avenues for making the mail they send to American households and business even safer than it is today."

Mail-related industries ranging from catalog sales to greeting cards to film developing employ 9 million Americans and contribute $900 billion to the national economy annually, Potter noted.

While more than 30 billion pieces of mail have been delivered since Sept. 11, just three letters are known to have been tainted with anthrax, though others are suspected.

Those letters "have done damage to the psyche of the American public when it comes to handling mail," Potter said. "We are going to work together to ensure that we restore confidence in the mail."

Michael Sherman, president of the mail-order catalog company Fingerhut, said his business has changed its packaging to make the name of the company more visible on both parcels and advertising pieces.

"We want people to understand what it is that we're sending them and that it's from us," he said.

Sherman and others said they have not encountered major problems getting mail delivered. Postal officials have said service is normal in most of the country, though there have been delivery problems in areas affected by anthrax, such as Washington.

C. Hamilton Davison Jr., president of Paramount Cards, encouraged people to put return addresses on all items.

"That's a big help. When the recipient gets a package or envelope from you, they're going to recognize that name, and they're going to recognize that address," he said.