As an avid follower of SMTP protocols against spam and emerging anti-spam technology, I was surprised to see the U.S. is the #1 leading country when it comes to relaying spam email. In a recent report by Sophos on the Top 12 Spam Relaying Countries, the US accounted for almost a quarter of all spam relayed email. This is not good for the email world of communication.
Spammers are here to stay and worst off they are ahead of the anti-spam solutions. I believe there is a threat to email as other technologies become more popular for collaboration and communication. The problem is not just with email but as user change technologies, spammers are a step ahead. As Nathaniel Borenstein points out, the solution may not be a product, but a legal and economic approach.
For more information on preventing spam in Domino: Controlling spam: Advanced SMTP settings in Lotus Domino
U.S. is atop the spam relay list