aki_no_kaze kindly told me how to turn on the anti-spam feature that requires all posters to solve a captcha before posting. Thanks Aki!
Sorry for the tiny inconvenience to the community, but I know how much you all hate spam, so I felt this would be a small price to pay for a little peace and quiet. :)
Please send all your flowers of gratitude to aki_no_kaze. :) I just pushed the buttons.
Edit: Actually, apparently aki told me how to do this SEVEN WEEKS AGO according to the timestamp on the email. I only now saw it because I got a new spam notification and dealt with it, then noticed an unread email that explained this.
I'm terribly sorry for not turning this feature on immediately. I'll try to be a better moderator from now on. :)