Using SpamAssassin to Test for Comment Spam

I had previously investigated the idea of using SpamAssassin to check comments and decide whether or not they were spam.

Here are some of my test materials. The first is a PHP script, the other is a custom set of spamassassin scores.

<?php

$sender = "user@example.com";
$subject = "Comment";
$date = date("D, d M Y H:i:s O (T)");
$date_old = date("D, d M Y H:i:s O");

echo <<<EOF
Subject: $subject
Date: $date
From: www-data@example.com (www-data)

hi
hi
hi
hi
hi

EOF;
?>

Spamc settings appropriate for comments:

score MISSING_MID 0.0
score NO_RELAYS 0.0
score NO_RECEIVED 0.0