Having got completely fed up with the wonderful Christine Hall sending me copious amounts of spam by trawling my sites for email addresses, I finally did something about it. I've added the following rewrite rule to my Apache config:
RewriteEngine On
RewriteCond %{REMOTE_ADDR} ^211\.101\.236\.*$
RewriteRule ^.* /fuckoff-trafficmagnet.html [L]
which serves fuckoff-trafficmagnet.html instead of the usual content to anything coming from what I believe to be trafficmagnet.net's subnet. With any luck their spamming software doesn't check the hostname of the receiving mailserver :-) Let's wait and see...
If you're a user on budvar, simply put the following lines in your server.conf
Include /home/web/generic/conf/anti-trafficmagnet.conf
and symlink or copy /home/web/generic/pub/fuckoff-trafficmagnet.html