I think many of us here hate spam. Usually, a spam contains inappropriate messages containing urls to some unknown websites. The websites can sometime contain links to file containing virus, Trojan, or other securities threats. This may lead your computer to some problems which can become really troublesome. My friend has been hit by a flood of spam recently and he has no choice but to delete the comment table from his Wordpress database.
Preventing spams is an important thing to do and here’s what you are supposed to do to avoid your Wordpress blog from getting hit by spammers. Since the first time using the Wordpress blog, I have found two very effective plugins which do the job very well. One is Bad Behavior and the other one is Spam Karma. I am currently using Bad Behavior on my blog. Optionally, you can add the Bad Behavior Stats Plugin to display the number of blocked attempts on your blog.
Besides using those two plugin, consider using Askimet (built-in Wordpress) as an alternative. How does Askimet works? Well, basically when a new comment, trackback, or pingback comes to your blog, it is submitted to the Akismet web service which runs hundreds of tests on the comment and returns a thumbs up or thumbs down. To use Akismet, you need an API key. You can get a free API key by registering for a WordPress.com user account. The API key will be emailed to you after you register. Please not that the free API is for personal use only.
Now, after installing those plugins, one of the tricks that you can apply to Wordpress is by limiting the number of links in comments. To change the number of links in comment posts which may help stop comment spammers who include dozens of links in their comment posts, try this method:
Go to the Options > Discussion panel.
* Scroll down to Comment Moderation.
* In the section which covers the number of links in a post, it is set to 2 by default. You could lower to one.
NOTE: Do not set this to zero or leave the field blank. It will send every comment to moderation — not the desired effect
Conclusion
There is lots of customization that available for Wordpress to avoid spam form getting into your blog. The mods above are my recommendation and your result might be varied. Any comment, question or suggestions, let us discuss in the comment board.