The United States, with anti-spam laws in place, still tops the "Dirty Dozen" list of countries that spew the most unsolicited e-mail, a new survey says. Security experts at Sophos, in Lynnfield, Mass., said in an announcement Monday that although the U.S. is still the most prolific spam source, its output has dropped dramatically, from 42.5 per cent of the world's spam in late 2004 to 24.5 per cent in late 2005. Canada has increased its spam output its spam volume marginally in that time frame — from 2.9 per cent to 3 per cent — but still has a grip on a distant fifth place in the Dirty Dozen list. Sophos created the list by deploying "spam traps" — computers without protection designed for that purpose — around the world, and tracking their source to the countries where the spam made its final journey. The company credits tough legislation such as the U.S. CAN-SPAM Act and greater information sharing by Internet Service Providers, for the drop in the U.S. figures. The country has imposed strict penalties and fines for those found guilty of spamming, including a $11.2-billion (U.S.) judgment against Florida-based spammer James McCalla. Another spammer, Daniel Lin of Detroit, faces a sentence of at least two years imprisonment for his actions.