Receiving spam bounce-backs from my WordPress site
Posted 18th декември, 2018
When a website is experiencing a spam bots attack your mailbox might fill in bounce-back emails from the "Mail Delivery system" stating the message failed, or other automated emails filled with SPAM.
The easiest fix for the issue is to enable captcha on your forms.
What is captcha
This is an authentication test based usually on images. It would provide text or random characters in an image and request you type that to a text box, or make you select images matching certain keyword, depending on the captcha type.
Why a captcha?
The captcha authenticates that the one who is posting on a form is in fact a human and not a bot. The spam bots are usually automated scripts that would fill your mailbox with spam, but there are other types of bots that can use any form on your website (comment form, contact form/ booking form) and attempt to run malicious scripts directly to your database.
All of this is easily stopped by a captcha as the automated bots cannot authenticate through it.
Which captcha plugin to use?
While there are multiple of captcha plugins to use, please use only the reCaptcha type of plugins (that is the Google captcha) as other types of captcha (being math captcha or text captcha) can conflict with your caching plugin or other settings on your hosting environment , causing a constant incorrect value error.
Best reCaptcha plugins are:
Contact Form 7 Captcha - build to be integrated to contact form 7 plugin, but it can be used with other form plugins as well (excluding premium plugins).
Advanced noCaptcha & invisible Captcha - this is also a great plugin that can be integrated to your current form plugin and has the ability to add multiple of captchas to a page.
Simple Google reCAPTCHA - this plugin can add captcha to all registration, log in and commenting forms, but not to a contact us form.