I’ m sure that there are plenty of posts on this topic, but we have had first-hand experience for several years in dealing with comment spammers. Each of the plugins below are in use by the EffortlessHR Blog and they all work in uniquely different ways to stop bots and spammers dead in their tracks. Today we are going to share our winning combination, in order of importance:
G.A.S.P. (GrowMap Anti Spam Plugin)
This plugin also comes installed with CommentLuv Premium. It’s very simple in design and adds a checkbox to “Confirm you are NOT a spammer” to your comment form. It also performs some validation and limits the maximum number of links that can be present in comment text. It can also enforce that the user is on the page for a certain amount of time before leaving a comment.
It is extremely effective at preventing automated spam.
Stop Spammer Registrations Plugin
I know what you are thinking.. Registrations? This plugin could use a new name, but there is no arguing with how effective it is, and contends with G.A.S.P. as being the best plugin. I just looked at my statistic screen for the plugin and saw this message — “Stop Spammers has stopped 66668 spammers since installation” — that should explain how great it is.
This plugin checks against StopForumSpam, Project Honeypot and BotScout to to prevent spammers from registering or making comments. The Stop Spammer Registrations plugin works by checking the IP address, email and user id of anyone who tries to register, login, or leave a comment. This effectively blocks spammers who try to register on blogs or leave spam. It checks a users credentials against up to three databases: Stop Forum Spam, Project Honeypot, and BotScout. Optionally checks against Akismet for Logins and Registrations.
Akismet
Akismet is what kicks in if/when a comment makes it past the other plugins, which does happen.
It performs further analysis on the comment information and visitor to determine if the post is legitimate.
There you have it, simple and easy. With this combination, we very rarely have to moderate or flag comments as spam. Almost all comments that make it through are legitimate and these plugins work in ways that result in very few false positives.