This software is currently in use on our servers for stopping spam and for making us more sound on 2senet. The current version is: 1.1.2
In order to be a sound site on Usenet-2, an ISP has to be very diligent tracking posts from its users. It should be impossible for spam to come from its users, however spam detection software tends to be iffy at best. Mostly it relies on searching for strings in posts like "$$$", or having a list of spammers that you can block. The first method suffers because it is computationally expensive, and because it is not absolute. The second suffers because knowing your spammer usually means your spammer has sent out 20,000 posts and your newsmaster has had his mailbox flooded by thousands of angry usenetters.
The News Shogun is a post-filter for INN and Typhoon which can:
Every filter in the system is configured based on a series of conditions that the current user and article may, or may not flag. This means that you can tell the filter to allow joe-user to be able to post to any newsgroup however much you want him to, except for, when he's posting to Usenet-2, where he would only be allowed to post a much smaller number of messages.
Here's how it works:
When the user attempts to post a message, post monitors related to the limits are invoked on the message. If anything about the user's post runs contrary to the administration's posting policy, the post is blocked and a descriptive error message is relayed to the user.
The post can also be logged to a holding directory, where an external daemon will run into it and send it back to the news server. This can happen, for example, when the user has posted enough times that you want to see his posts, but few enough times that you don't want to block it indefinately.
Mail can be sent back to the user and to the administrators which will describe the reason the post got slowed, and how to get the limit raised.
We've finished writing a patch to the innd transfer server which will modify the format of hosts.nntp such that you can outright reject an article if it's destined for a particular hierarchy. Russ Allbery modified it, and here is his description of his modifications:
I didn't want the poison patch for hosts.nntp (and in fact exclusions in hosts.nntp in general) to result in entries into the history file even when REMEMBER_TRASH is set to yes. This is because, with Usenet II, one may receive sound articles via unsound paths before sound paths.
This patch is now a part of recent INN-2.0 beta snapshots. If you are running a post May 22, 1998 INN, you don't need to download this patch.
Find it at ftp://ftp.panix.com/pub/shogun/poison.tar.gz .