Thousands of consumers every year receive what appear to be official notifications that they've won a prize in a lottery drawing from another country. This is a scam. Common lottery scams involve the Canadian Lottery, the U.K. Lottery and the El Gordo Lottery (Spain).
Normally the letter says the consumer has won a large amount of money, but first needs to pay taxes on the money. Or the letter might include a bogus check for part of the winnings and ask that you send some of the money elsewhere. That “elsewhere” will be a criminal and the original check you received will bounce.