The Berkeley man has warned others not to be fooled either.

"Anything going cheaply is bound to be not much good," Mr Kennedy said.

"Nobody runs around giving you $40,000."

The letter guaranteed Mr Kennedy a large sum of money if he provided his credit card details to pay a small joining fee.

The company that sent the letter was called IWG, connected to EuroMillions lottery.

At first glance, the letter seemed legitimate, with an ABN number and "official" signature.

Mr Kennedy said he knew something was wrong when he saw the return address was the Netherlands.

"It came from Holland and I don't know anyone in Holland," he said.

Peter Palazzi, co-ordinator of ministerial and parliamentary operations at the NSW Office of Fair Trading, said Mr Kennedy's scam letter was only one of many.

"While there are a variety of lottery scams in circulation they are essentially the same," Mr Palazzi said.

"There are no prizes and any consumer who responds risks losing money and having their identity stolen."

Mr Kennedy was confused over how the scammers got his personal information.

"It had my full name, and I never sign my full name," he said. "I'd like to know how they got (my details)."

Mr Kennedy also found the language of the letter puzzling.

"It was like 'you are a silly goose - why haven't you claimed the $40,000 you've won?' " he said.

Mr Palazzi said millions of scams occurred each year, through mail, telephone, flyers, email, SMS messages and seminars.

Mr Kennedy, meanwhile, wants all residents to carefully check what arrives in their mail.

"If I've stopped someone from getting conned or robbed, all the better."