dragonara.net comment spam

[#1]

Anybody else having trouble with this? I'm using the plusnet formmail script and if a form is around for too long it gets hit by a lot of russian-ish comment spam, usually links, sometimes unintelligible.
Apparently one IP range 194.8.74.xx-194.8.75.xx accounts for most of it and traces suggest this is a UK operation.

[#2]

I haven't had any spam through that script on my site (18 months old), but I get plenty from another non-PN site I manage, which has been around a lot longer and is more easily found. As you say, it eventually gets discovered, so possibly the simplest defence is just to change the URL every so often

[#3]

Things that might be usefull...
If I could make the IP show in the message title it would help a lot. I could probably get my mail
client to discard the junk forms that way. For all I know this may be possible...
Adding "Recieved via HTTP" header entries might help, it might even allow the use of spam filtering on form results since the filter could see the true source IP.