Wayne Mansfield is a self-confessed "spam king."
Australian authorities claim he has sent tens of millions of spam emails over the last years. Mansfield says that the response rate to spam "is staggeringly high - people wouldn't do it if it didn't work".
He faces penalties of up to $220,000.
Mansfield said the real king of spam was American Scott Richter who sent more than 56 million spam emails an hour.