The US relays the most spam, says Sophos.

According to the security firm's 'dirty dozen' list, the US relays 13.1 percent of global spam, closely followed by India, which relays 7.3 percent and Brazil, which passes on 6.8 percent.

The UK tied with Russia and Italy at 3.1 percent, while China sits in a lowly 15th place.

The amount of spam relayed through Chinese servers has been falling steadily for some time says Sophos but its absence from the top names in the spam league table for Q1 2010 is still noteworthy.

Being a relay point does not mean that the spam was originally sent from this country, merely that it uses points of presence in that country - servers and botnet zombies - to hide the real point of origin.

Indeed, there is an argument that relay points are one of the less meaningful measures of who is sending spam to whom and where from.

Recent analyses, including one by Symantec, has suggested that China's position as a major node for internet crime has dropped slightly or it could just be that other countries are rising in relative terms.

Symentec's figures for the whole of 2009 put China in eighth place for spam zombies, well behind number one zombie hotspot, Brazil.

"Countries such as the USA would do well to remember that cleaning-up infected PCs in their own back yard will be an important step in fighting cybercrime. Furthermore, we all shouldn't forget that if no-one bought products sold via spam there would be a lot less incentive to send junk email," said Graham Cluley of Sophos.

See also: Spam volumes grew 6 percent last year