Terms of Service

last updated: 2026-06-10

1. The service

Catch-All Checker ("the service", "we", "us"), operated by NullMX Labs (Tallinn, EE), provides email verification: single lookups via this website, bulk CSV verification, and a REST API. Verification results (deliverable, undeliverable, risky, unknown, and associated flags) are best-effort assessments based on live network checks at the time of the request. We do not guarantee that any individual result is accurate, or that a "deliverable" address will accept any particular message.

2. Accounts

You must provide accurate registration information and keep your credentials and API keys confidential. You are responsible for all activity under your account and keys. We may suspend or terminate accounts that violate these terms.

3. Lookups and billing

The service is sold as prepaid lookups; one lookup covers one verification. New accounts receive 100 free lookups with no payment method required. Paid lookup packs are processed by Stripe; we do not store your card details. Inconclusive lookups (results returned as "unknown") are refunded automatically, on single checks and in bulk. Lookups are non-transferable. Except where required by law, purchased lookups are non-refundable once consumed.

4. Acceptable use

• Use the service only for lawful purposes and in compliance with applicable anti-spam and data-protection law (including CAN-SPAM, PECR and the GDPR) when emailing any list you verify.
• Do not attempt to circumvent rate limits, free-tier quotas, or the proof-of-work challenge on the free checker.
• Do not resell raw access to the service without a written agreement.
• Do not use the service to harass individuals or to facilitate abuse, fraud or phishing.

5. Fair use and rate limits

API usage is limited to 120 requests per minute per key, and bulk jobs to 50,000 addresses per job. The free on-page checker is limited to 5 lookups per IP address per day. We may throttle or refuse traffic that degrades the service for others.

6. Disclaimer of warranties

The service is provided "as is" and "as available", without warranties of any kind, express or implied, including fitness for a particular purpose and non-infringement. Mail-server behaviour is outside our control and verification outcomes can change at any time.

7. Limitation of liability

To the maximum extent permitted by law, our total liability arising out of or relating to the service is limited to the amount you paid us in the twelve months preceding the claim. We are not liable for indirect, incidental, special or consequential damages, including lost profits, lost data, or damage to sender reputation.

8. Termination

You may stop using the service at any time. We may suspend or terminate access for breach of these terms, with notice where practicable. Sections 6–9 survive termination.

9. Changes and contact

We may update these terms; material changes will be announced on this page with an updated date. Continued use after changes constitutes acceptance. Questions: [email protected].