Spam-identification tools

• Whois searches for
  • North America (except Mexico) etc.
  • Latin America and the Caribbean
  • Europe etc.
  • Africa
  • Asia Pacific (There are separate whois databases for Korea and Japan.)
  One can also use one of several whois clients, such as whois, gwhois and jwhois. These clients will try to figure out where to ask.
• nslookup
• traceroute (restricted access)