diff --git a/awesome-privacy.yml b/awesome-privacy.yml
index 2dd3550..ec62b1d 100644
--- a/awesome-privacy.yml
+++ b/awesome-privacy.yml
@@ -1090,6 +1090,14 @@ categories:
           Verifies DKIM signatures and shows the result in the e-mail header, in order to help
           spot spoofed emails (which do not come from the domain that they claim to).
 
+      - name: Captchainbox
+        url: https://captchainbox.com
+        icon: https://captchainbox.com/logo-512.png
+        openSource: false
+        description: >-
+          CAPTCHA-based email filtering for Gmail. Known contacts pass through,
+          unknown senders verify via a simple CAPTCHA. Verified senders are auto-whitelisted.
+
       notableMentions: >
         If you are using ProtonMail, then the [ProtonMail Bridge](https://protonmail.com/bridge/thunderbird)
         enables you to sync & backup your emails to your own desktop mail client.