> Does anyone know of a way, that whenever someone emails
> from say, for example, Nigeria, Korea, Russia and
> China, the email gets returned to them, saying
> something like, "Email failed, no such email address"
> please ?
You can use the DNS blacklists at blackholes.us to block based on sender
countries. Lying about why the message was rejected is going to be something
you have to do in your MTA, and I'd consider it an extremely bad idea
because it's going to make troubleshooting difficult.
--
Dave Pooser
Cat-Herder-in-Chief, Pooserville.com
"The greatest dangers to liberty lurk in insidious encroachment
by men of zeal, well-meaning but without understanding."
-- Justice Louis Brandeis
