Hi,
I assume this is asked once someone clicks the opt-in link, not for submitting the form?
Once the form is submitted it’s out of our hands, from there MailChimp.com handles everything including the double opt-in email.
I believe they show that captcha based on the country of the subscriber but I’m not sure what their algorithm is for this.
I guess the only way to circumvent this is turning off double opt in for the form, under MailChimp for WP > Form > Settings.
Please note we are not affiliated with MailChimp.com. We are a different company “ibericode” that develops plugins such as “MailChimp for WordPress”. I’m sorry to tell you I am not able to help you with this question as it is not related to our plugin. My advice to you is to contact MailChimp.com as they would be the best people to answer any query related to your MailChimp.com account.
You can contact MailChimp.com trough https://mailchimp.com/contact/support/
I hope that helps. If you have any queries specific to our plugin please let us know!