The letters promised dodgy health products, non-existent lottery prizes and fortune telling, but the massive seizure of scam mail has now gone to the shredder in Western Australian.
More than 346,000 letters promoting more than 100 scams have been intercepted in a joint operation between Consumer Protection and Australia Post since February.
Commerce Minister Michael Mischin said this year's haul had more than tripled from last year, showing that although mail interception methods were improving, the scam business was also booming.
"The increase indicates that overseas promoters continue to cash in on innocent people and are prepared to send enormous amounts of mail to increase their chances of getting a return," he said.
Some of the scams in the latest haul include order forms for dubious health products, clairvoyant predictions and secrets to success for a fee, and non-existent prizes and lotteries.
Mr Mischin said despite the efforts of authorities, people still needed to be aware of the tempting tactics of scammers.
"Remember, if it sounds too good to be true, it usually is," he said.