I have several Wordpress blogs. All of them are protected by akismet. But you know that sometimes even akismet is wrong so it traces ham as spam and places it directly into the spam folder. The problem is that I get daily in the spam folder more than 500 non-human comments. So I have to parse through them in order not to miss one-two wrongly categorized hams. Is there any chance to completely block all such non-human sent messages in order that in the spam folder I only get the "human spam"?
try using a different comment system... like disqus: http://wordpress.org/extend/plugins/disqus-comment-system/
Try a Google reCaptcha plugin. There are some spam bots that can crack reCaptcha, but it's better than nothing and I haven't seen any problems with Akismet before.
I thought about this, but this will make my users not so happy having to enter the captcha again and again and again...
put Captcha on your blog and install wpspam free, I know your visitor may not happy with that. or you can install this Growmap Anti Spambot Plugin, user will not type captcha, but they just click an option that they're not spam
I use a combination of Akismet and captcha and it works for me. I've tried the Growmap Anti Spambot plugin too and it's great but the bottom line is you would still need to weed out comments once or twice a week.
I really don't think there is no way to automatically identify the spam bots without any captcha or any action user has to do
Using captcha is a better way to stop spamming on your blog. Sometimes visitors don't like it but it is necessary.
Akismet is not yet reported to have problems as you say. Captcha may be a hindrance, but it is believed to be more of a relief than a menace. So if has come to it, somewhere there has to be a compromise... either use recaptcha (plugin) and lose a little on human-generated content, or use akismet (and the likes) only and spend hours filtering out useful comments.
I don't think it's a nuisance at all. Anybody leaving a comment in any part of the web these days would know what a captcha is for and any webowner I think would be using it on their websites. It's a great way of circumventing spambots. So it serves as a precautionary measure for both webowner and commenter.
A lot of those spam that you are getting is actually from real people. Putting some sort of plugin will not help. You can try this method: http:// codex.wordpress.org/Combating_Comment_Spam/Denying_Access#Deny_Access_to_No_Referrer_Requests But like I said, it won't necessarily bring down your comment spam.
From playing around with spam tools in the best I've come to know that the best way to prevent automated bots is not with a captcha, because those can be broken using services like decapcher.com, but rather, place a unique question to force the visitor to prove they are human. Most spam tools do not have math solving capabilities, but some do, so it's best to have a question that requires the user use a tad bit of thought, like... Answer: How much wood could a wood chuck chuck if a wood chuck could chuck ___? Fill in the blank and press submit to comment.
I will suggest you to use Growmap Anti Spam Plugin, it is the best plugin I ever used. A combination of Growmap plugin and Akismet prevents nearly 99.9% of spam bots.
I deny. Even I use the plugin mentioned above and it fails. It is very easy to write a comment spamming script to defeat Growmap Anti spam plugin along with Akismet. I think both along with Conditional captcha plugin can help solve the problem. Infact the best thing is to have reCaptcha installed.