In this post, Pioneer Web Design will show you how Using WordPress To Block Comment Spam can be done readily from the WordPress admin panel.
In my humble experience, there are techniques built into WordPress that make Spam comments very much a non-issue:
A) Moderate all comments: Admin Dashboard>Settings>Discussion>Before a comment appears>An administrator must always approve the comment
B) To place all comments with (spam) links into spam comments: Admin Dashboard>Settings>Discussion>Comment Moderation>Hold a comment in the queue if it contains> 1 >or more links. (A common characteristic of comment spam is a large number of hyperlinks.)
C) Then: Admin Dashboard>Settings>Discussion>Comment Blacklist> Add to this list:
D) Admin Dashboard>Settings>Discussion>Other comment settings>Automatically close comments on articles older than>14>days
(Leaving comments open for a long time will have the biggest impact on how many spam comments are received)
E) Admin Dashboard>Settings>Discussion>E-mail me whenever>A comment is held for moderation>Comments sent to spam are not emailed.
F) Update the comments form to note that comments are moderated, links not allowed, and language must be about the post/page.
G) Empty the Comment Spam daily (often)>Check all>Delete Permanently.
You can now rest assured that some bot is not going to flood your site with bad links. As you can see, we can use the built in features in WordPress to control comment spam.