Hi All,
I've written a basic Sendmail milter in Perl using Sendmail::PMilter which uses the SpamAssassin libraries with just the 20_uri_tests.cf rules file (so it is relatively light) to strip the URI's from a message and then check them against multi.surbl.org and black.uribl.com and reject any messages that contains blacklisted URI's.
It's rough code at the moment - there's no whitelisting or any start/stop scripts for it yet and this is my first attempt at anything in Perl - I've been running it on our spam trap for a while now and it's worked very well, I have not tried it on a production system yet.
I'm posting it here in case anyone finds this useful and for comment - It can be downloaded from http://www.fsl.com/support/milter-uri.pl -- installation instructions are in the file.
Finally - I'd like to say thanks to everyone involved in both SURBL and URIBL projects, you all do an excellent job of making lives difficult for the spammers :-)
Kind regards, Steve.