Shirley Ware of Flemington, W.Va., who won $1.6 million in Maryland's state lottery last year, had gotten her lucky number through the mail -- a practice that is illegal, U.S. Postal Service officials said yesterday.

Ware, who said at the time that she derived her winning Lotto number from the birthdays of herself and her husband, may be among the last beneficiaries of lottery winnings by interstate mail in the wake of a crackdown on six states that began this week.

Thomas Ziebarth, an attorney in the Postal Service's consumer protection division, said that Maryland, New Hampshire, Michigan, New York, Rhode Island and Massachusetts are violating federal postal laws by allowing gamblers outside their borders to play by mail in their state-run lotteries.

"There have been letters of inquiry asking , 'How come we can't send raffle tickets through the mail and the state can send lottery materials?' " Ziebarth said. "They're right. We can't look the other way."

State lottery officials in Maryland and other states expressed dismay at the Postal Service crackdown, of which they were notified in letters sent to them last week.

"It's always been kind of a hazy thing," said Robert J. Laird, deputy director of marketing for the Maryland agency. Postal regulations, he said, were designed to discourage illegal gaming across state lines, not legal state-run lotteries.

Ziebarth said that lottery materials can be sent through the mails under an exemption in the federal statute, but only to addresses in the state from which they are mailed.

Representatives of the states affected by the Postal Service directive said yesterday that they have not decided whether they will challenge what they consider to be a new interpretation of the law.

New York State Lottery Director John Quinn questioned how such a decision can be enforced when legislation is pending on Capitol Hill that would set up a national lottery, for which tickets would be sold through local post offices.

"You run into some strange dichotomies here," he said.

Quinn and Laird said that mail lottery subscriptions account for less than 2 percent of their states' weekly ticket sales and that suspending interstate mail sales would not have a significant financial impact on their state lotteries.

"But there is definitely principle at stake about whether the federal government can tell states what they can and can't do," Laird said.

State lotteries may not be the only losers if the Postal Service's crackdown sticks. Entrepreneurs such as Robert Frank, a 43-year-old Sacramento, Calif., telecommunications consultant, could be forced to close businesses that advertise the joys of winning money legally by gambling through the mails.

"Out here in California we have lottery fever," Frank said. California residents in November voted to approve the creation of a state lottery that is supposed to begin this year.

"When lottery laws were put into effect in the 1890s or whenever, they were meant to protect the public from shysters and scams," added Frank, who registered his month-old business in the Golden State as Mr. Lottery and sells the state lottery addresses to people in the Sacramento area for $3. "Those laws are outdated."