example on the email Jim listed it was from goldenlink.com.br so forward a copy of the letter to abuse@goldenlink.com.br with a nastygram, also send the whole email as an attachment. If you are using a Cloudmark toolbar immediately report it back to cloudmark. Vipul Razor users (freeware) do the same.
it doesnt stop it but slows it down tremendously.
thanx,
bill