Spam can be annoying and even harmful for your WordPress website. It can effect the website performance, contain malicious malware, harm SEO, slow down the website, etc.
To keep you and your website visitors safe you should follow a few tips:
1. Create a blacklist containing certain words banned from your WordPress website. Every comment containing at least one of these words will be automatically deleted from your website. You can find this feature in your WordPress dashboard, go to Settings > Discussion > Disallowed Comment Keys.
2. Allow only registered users to leave comments. This may protect your website from some spammers and hackers. Go to Discussion > Other Comment Settings and check the box saying “Users must be registered and logged in to comment”.
3. Optionally you can select to automatically close the comment section for older posts in the same section to limit spammers.