Using Friendly Captcha in HTML subscription and unsubscription forms

With Friendly Captcha, you can protect yourself against so-called list bombing attacks, for example. In a list bombing attack, subscriptions to your newsletter are made by computer programs or bots. In this process, a very large number of fictitious or actually existing email addresses are transferred to your subscription form and the subscription process is triggered (double opt-in) or even carried out (single opt-in). The owners of the email addresses know nothing about this.

You can use Friendly Captcha in your HTML subscription and unsubscription forms by using Subscription Servlet version 3.

The version of Friendly Captcha used in Subscription Servlet version 3 automatically determines based on algorithms whether a human or a computer program is visiting a web page. Unlike Google reCAPTCHA, Friendly Captcha operates completely in the background. No need to recognize objects in pictures or decipher slurred words. For more information, please visit:

On the web page, only a captcha icon will be displayed:

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Friendly Captcha is an alternative to Google reCAPTCHA. Use Friendly Captcha (like all third-party software) only in consultation with your privacy officer to ensure that you comply with current privacy laws.

Additional information

More information about Friendly Captcha can be found at:

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