The statistic is a genuine concern to SpamTrap chief executive Andrew Kent, despite the likelihood that it will lead to a boost in business for his company.
"We've just closed off May and done the sums. 55.8 percent of all customers' e-mail was spam," he said.
According to Kent, the cross-over happened in April.
"April for us was just over 50 percent. It was a transition month," he told ZDNet Australia.
MessageLabs, another mail filtering company, has released similar statistics, showing 55.1 percent of all messages scanned in May were spam.
The scourge of spam is a genuine threat to the usefulness of e-mail when "you start looking at some other numbers," Kent says. "We think there's about 50 million e-mails in Australia sent every day. We're taking an estimate that one third of that is spam".
The fact that the ratio of spam is higher among SpamTrap users than the general population is because the customers usually sign up because they're being spammed stupid, Kent says.
As for legislation that's going to make spamming a crime in Australia, he is looking forward to it being tabled.
"We haven't heard much about it, we're hoping they're going to hurry it up," he said.
Spam spam spam spam spam spam spam spam Wonderful Spaaam wonderful spam!
I think Monty Python saw the future.