I disabled the trackback facility on my blog months ago because I was getting a lot of trackback spam. Around the same time I wrote a SpamAssassin Plugin for Movable Type. I effectively took MT-Blacklists regex database and converted into a form compatible for SpamAssassin and then wrote the plugin. Of course at the time I had disabled trackbacks so I only wrote it to handle comments and it has been going a great job because I get virtually zero blog spam now that the database is trained.
Of course now that I have turned on the trackback facility again I now have trackback spam to deal with. Of course this time I am not going to forget about it so await an update and I will release anther version that will handle trackbacks as well.
As promised this is the extended entry. I have now just added trackbacks to the spamassassin plugin. It was easier than I thought. It took 2 hours to finish it, now all I need is someone to test it. As soon as I have packaged it up into a tar ball I will release it.