Reducing spam comments to your blogs.perl.org blog
Since I’ve never used MT before I signed up to blogs.perl.org, it’s only recently that I found that MT does have some spam settings, which unfortunately are not turned on or default to the most conservative value. Along with other settings, you can reduce the number of spam comments being posted/notified to you.
You can increase spam detection aggressiveness (Preferences → Spam). By default this is set to 0 which allows many spams to pass through. I set this now to 5 which seems to be okay (so far only 2 spams after a couple of days).
You can disallow anonymous comments (Preferences → Comments → Setup Registration) or at least require email verification. By default anonymous comments are turned on and email verification is not required.
You can use CAPTCHA! (Preferences → Comments). By default this is off, and unfortunately when I tried to turn it on (either using MT’s own CAPTCHA or reCaptcha), no image is displayed and yet all comments got rejected with the message “Text entered is not correct”. I guess this is currently a bug.