Problems with sending comments to spam

I tried very hard to like this plugin. Unfortunately, it sent every comment post to the spam folder. Other elements of my site use Google reCAPTCHA also without issue–contact, guestbook, etcetera. But any comment from comments, Nextgen gallery, and pages/posts ended up immediately in the spam folder. I ended up uninstalling and replacing with a simpler CAPTCHA plugin that did not cause the problem. Running 5.0.3 under PHP v5.6.40.