Screaming Penguin - Source Does Matter

An article at news.com puts 30-80% of spam getting into the network via open proxies. Spammers are apparently getting a bit more sophisticated (not a lot) and using open proxies to then connect to mail servers, etc. The old open relay game is still alive as well, of course, but most open relays have been quashed by the anti-spam publiclity and now there are fewer around (even in Korea and China, hopefully).

For more check the linked news.com article.   Lending spammers a helping hand: news.com