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Terms of Service

Effective date: April 14, 2026 · Last updated: May 11, 2026

These Terms of Service ("Terms") govern your use of Captchainbox, operated by Felix Doerp (sole proprietor, based in Germany) at captchainbox.com. By using the service, you agree to these Terms.

1. Description of Service

Captchainbox is an email protection service for Gmail. It automatically archives emails from unknown senders and sends them a CAPTCHA verification challenge. Once a sender completes verification, their email is unarchived and they are added to your trusted sender list.

2. Account Registration

To use Captchainbox, you must sign in with a Google account and grant access to your Gmail. You are responsible for maintaining the security of your account. You must be at least 13 years old to use the service.

3. Gmail Access and Permissions

By connecting your Gmail account, you authorize Captchainbox to:

  • Read email metadata (sender, subject, date) to classify messages
  • Modify email labels to archive and unarchive messages based on sender verification status
  • Send verification challenge emails to unknown senders on your behalf
  • Set up Gmail push notifications to monitor incoming messages in real time

You may revoke these permissions at any time through your Google Account settings. Revoking access will stop all Captchainbox functionality for that Gmail account.

4. Acceptable Use

You agree not to:

  • Use the service for any unlawful purpose
  • Attempt to interfere with or disrupt the service or its infrastructure
  • Use the service to send spam, phishing, or other unsolicited bulk messages
  • Reverse-engineer, decompile, or disassemble any part of the service
  • Create multiple accounts to circumvent usage limits or abuse the service

5. Service Availability

We strive to keep Captchainbox available at all times, but we do not guarantee uninterrupted or error-free operation. The service depends on third-party APIs (Google Gmail API, Cloudflare Turnstile) that are outside our control. We may modify, suspend, or discontinue the service at any time with reasonable notice.

6. Email Processing

By using Captchainbox, you understand and accept that:

  • Emails from senders not on your whitelist will be automatically archived. This may include legitimate emails that you want to receive.
  • Verification emails will be sent to unknown senders from your Gmail address. Recipients will see your email address.
  • There may be a delay between receiving an email, archiving it, and sending the verification challenge due to processing time.
  • The initial whitelist is built from your email history and may not capture all legitimate contacts.

7. Pricing and Payments

Captchainbox offers both free and paid plans. Paid plan pricing, features, and billing terms are displayed on the website. We reserve the right to change pricing with 30 days' notice to affected users.

8. Data and Privacy

Your use of the service is also governed by our Privacy Policy, which describes how we collect, use, and protect your data.

9. Intellectual Property

The Captchainbox service, including its design, code, and branding, is owned by us. You retain all rights to your email data. We claim no ownership over any content in your Gmail account.

10. Limitation of Liability

To the maximum extent permitted by law, Captchainbox is provided "as is" without warranties of any kind. We are not liable for any indirect, incidental, special, or consequential damages arising from your use of the service, including but not limited to:

  • Missed or delayed emails due to archiving
  • Verification emails that are not delivered or are marked as spam
  • Unauthorized access to your account due to compromise of your Google credentials
  • Service interruptions caused by third-party API outages

11. Termination

You may stop using Captchainbox at any time by revoking Gmail access and deleting your account. We may suspend or terminate your account if you violate these Terms. Upon termination, we will delete your data in accordance with our Privacy Policy.

12. Changes to These Terms

We may update these Terms from time to time. We will notify you of material changes by posting the updated Terms on this page and updating the "Last updated" date. Continued use of the service after changes constitutes acceptance of the new Terms.

13. Governing Law

These Terms are governed by the laws of Germany. Any disputes arising from these Terms or the service will be resolved in the courts of Germany.

14. Contact

If you have questions about these Terms, please contact us at felixdoerp@gmail.com.