By default, the MailChimp for WordPress plugin uses various techniques to prevent spam sign-ups. Unfortunately, some spam-bots are smart enough to get through and more actions might be required. Bots are getting smarter everyday and sometimes even target your sites in a specific way.
If you’re suffering from spam sign-ups, the following methods will help you reduce and maybe even eliminate them.
Enable double opt-in
Double opt-in is a method where your subscriber will receive a confirmation email for your list. Most bots will not be able to get through to your list when this option is set to yes.
You can find this setting when editing your form; scroll down to find MailChimp Settings and set the double opt-in to yes.
This should prevent most of the spam sign-ups!
Install the WP Bruiser plugin.
The WP Bruiser plugin (formerly called Goodbye Captcha) uses a highly effective anti-spam technique which does not even require your visitors to fill an additional field. We’ve integrated this plugin with our so they work together seamlessly. If you’re having issues with spam sign-ups, this is a plugin we highly recommend!
Add a CAPTCHA field to your sign-up forms
Another guaranteed show-stopper for bots is a CAPTCHA field, although this can reduce the number of people subscribing to your lists. It requires subscribers to fill in another field, and some will find that too much effort.
We suggest only adding the CAPTCHA field if the previously mentioned methods don’t work for you.