What I do is I find out what web based email server they are on ..
So if they send an email from a yahoo.com or hotmail.com account, I forward the email to
abuse@yahoo.com or
abuse@hotmail.com.
In the re subject line I put "419 SCAM CLOSE THIS EMAIL ACCOUNT". This will close the email account till they open the next one (minutes later of course). But it would stop them for a bit if they are in the middle pulling the scam on someone.
