Readers: After a intense and much appreciated effort, my new anti-spam filter, Anti-Spam by CleanTalk, has solved the commenting problem that has plagued the website for the past two months. It seems the re-Captcha plugin was interfering with every anti-spam filter I tried, thus throwing all comments into the spam folder.
As they have advised, I have deactived re-Captcha (something I think my readers will like anyway), and comments now appear to be properly screened, with legitimate comments posting immediately and spam getting blocked.
Thank you CleanTalk! I must further add that in my effort to fix this problem, I tried five different anti-spam filters. Only CleanTalk was willing to work with me. All the other filters were typical software operations, treating the customer as an annoyance that they wished would go away.
CleanTalk’s personal support was refreshing and very much appreciated. If only more software operations would do the same.