SPAM comments and trackbacks are a big headache for everyone who manages their WordPress website. It is difficult to control the amount of unwanted comments once the site has find its place on the search engine. However, you can reduce the SPAM comments by making use of plugins designed for this purpose.
Akismet is a popular plugin used in every WordPress based site. By default, every WordPress installation automatically include a copy of Akismet. You just need to activate it from your WordPress admin dashboard to use the plugin.
After activation, navigate to Plugins | Akismet Configuration page and provide the API key on the displayed page.
How to Fetch API key?
Browse https://akismet.com/signup, select a package suited to your needs. If you need a key for your personal site then you should select Personal package and login using your existing WordPress.com username and password. Your Akismet API key will be displayed on the screen as shown below
You should copy and paste the above displayed key on the screen displayed in Figure 1 inside your WordPress Admin dashboard.
If you don’t have an API key then you should register on https://akismet.com/as a new user.
If you already have an API key from WordPress.com then you can make use of the same credentials (username and password) to fetch Akismet API Key.
As soon as you update your WordPress installation using your Akismet API key your site is protected from unwanted comments and trackbacks. You will be able to find the number of entries trapped by Akismet from the WordPress dashboard.