World Map of Spam Sources

Postini - (they make a server side email filter) - has published a map of the world - color coded by how much spam various regions send.

The data is based on the amount of junk e-mail intercepted by their software.

Surprisingly - the offending areas are very concentrated. The worst offenders seem to be certain regions in the United States, Brazil, Southeast Asia with a couple different hot spots in western Europe.

Some spam software uses regional information about spam sources to help determine if email is legitimate or not.

SpamButcher's email filters only factor in sending location in a few extreme circumstances from regions without any paying customers.

The data presented by Postini is presumably based on the originating email server. Sometimes the real source of spam can be hard to track. A server in one country can be used by a spammer in another.

Resource: World Map of Spam Sources