"Whether Australia is 28th or 23rd doesn't matter as what is good is that we have not seen anything even looking like a resurgence in spam relaying machines - there does not seem to be more computers infected by zombies this year," Ducklin said.

"The big deal is if we had gone back up and of course one thing driving other countries up the spam list is the more the population is connected online as spam is increasingly becoming a global problem.

"If you compare the economies and population of Japan and Australia, and the fact perhaps spam is newer in Japan, we are not doing to badly when you consider the Internet penetration and population size in Australia."

Japan was found to contribute some 1.7 percent to global spam levels, according to the report, ranking them number 12 on the list.