I'm getting bombarded with comment spam on this blog, even after installing MT-Blacklist. Something I've noticed after a spot of log analysis is that the kosher comments come from the HTML form generated by Movable Type at the end of each post, and are submitted by POST method (i.e. in the HTTP headers); the spammers use the GET submission method (i.e. in the URL query string). Am I missing something here? Make MT reject the form fields by GET and accept them by POST only?

I'm going to upgrade to the latest version, have a twiddle with mt-comments.cgi and report back ...