A short time after you start your WordPress blog, you'll more than likely find an email in your inbox or a notice on the WordPress Admin dashboard telling you someone has commented on one of your posts.

Most new bloggers will be happy, thinking someone has read their blog and cared enough to comment. Unfortunately, roughly 86% of all blog comments are spam¹.

A few steps you can take to cut down on (or eliminate) WordPress comment spam:

A drastic measure you could take is turn off comments, but then you'd get no feedback on your posts, and users like to comment on good blogs.. so this is usually not the best choice.

The next steps you can take are to force users to provide their name and a real email address, and for you to moderate all comments before they appear on your blog.

In the Admin > Dashboard > Settings > Discussion area, set some or all of the following, (to be extra safe, you can have all of these checked off)...

E-mail me whenever:

[_] Anyone posts a comment
[_] A comment is held for moderation
[_] Before a comment appears

Before a comment appears:

[_] An administrator must always approve the comment
[_] Comment author must fill out name and e-mail
[_] Comment author must have a previously approved comment

Then fill in the setting in the Comment Moderation area.

You may want to set the number of links that a user can include in a comment to "1", (one). You do this by having WordPress hold the comment in the moderation queue anytime there are (2) or more links in the comment.

Also in the Comment Moderation section, you can list some common spam words or known spammer's IP addresses and WordPress will block these comments too.

Even with every one of these set, on a busy blog, you could end up spending more time checking through all the comments than you do wrting new posts.

...that is, unless you install Akismet.

If you've downloaded and installed a recent version of WordPress, the Akismet plugin is included in the archive and is very simple to setup.

Briefly, what Akismet does is checks comments posted to your blog against a massive database of spam from blogs around the world. This is done transparently between the time the user posts the comment, and the time you get the notification. The underlying principle is: if it looks like spam, smells like spam, and tases like spam -- it's probably spam. Spammers are usually not "people" per-se... well, a person is behind it, but the work of posting the spam comments is ussualy done by a form-bot. This is an automated type of script that goes out on the web, looks for common submit type forms, and insets a message (usually containing links to a site selling something -- the common types of stuff like you find in email spam -- things I won't mention here, because I don't want my blog associated in any way with this stuff).

Since the spam comments are generated by a script, the email addresses are pretty mcuh all spoofed or just plain fake. There is no sense in replying to ask someone not to spam you, (in fact, this will probably get you more spam if the message does end up going through).

Akismet works by comparing spam comments submitted to your blog against all the other spam IP addresses, email addresses, text and links in the spam itself and can easily recognize spam froma genuine user's comment -- over 99% of the time Akismet gets it right. The spam comments (and any false positves) are held in a que, and with a single click you can delete them all.

To install Akismet in WordPress, either download the plugin from http://akismet.com/download/, (but first, look in your Plugin area chances are you already have it and it's just not installed).

If you already have it, skip ahead to #4,

1). download the archive akismet.zip

2). expand, ("unZIP") the contents into a folder on your local machine.

3). upload the entire /akismet/ folder to your wordpress /wp-content/plugins/ folder

4). go into the WordPress admin and click Plugins.

5). check off Akismet and then click Activate.

6). An application key is needed to run the software, (free to non-comemercial sites which are defined as sites earning less than $500 from their blog read the details on the Akismet site for details about comemrcial and "pro-blogger" keys). To get the key you need to visit WordPress.com and register if you don't already have an account, (the Akismet software is by Matt Mullenweg of WordPress fame).

Once it's installed, you can once again enjoy blogging without spending time worrying about comment spam.

¹86% percent of blog comments are spam fact reported by Akismet based on over +8,000,000,000 comments it has filtered... yes, that's over 8 BILLION!