Last updated: February 2026
These Terms of Service ("Terms") govern your access to and use of the Mailcaff email verification API and related services ("Service") operated by Mailcaff ("we", "us", or "our"), accessible at mailcaff.com. By creating an account or using the Service, you agree to be bound by these Terms. If you do not agree to these Terms, do not use the Service.
Mailcaff provides an email verification API that allows you to verify the deliverability of email addresses. The Service includes:
The Service is provided on an "as-is" basis. We continuously work to improve accuracy and reliability, but verification results are inherently probabilistic and should not be treated as guarantees of deliverability.
To use the Service, you must create an account by providing a valid email address and password. You are responsible for:
You must be at least 18 years old (or the age of legal majority in your jurisdiction) to create an account. If you are using the Service on behalf of a company or organization, you represent that you have the authority to bind that entity to these Terms.
The Service is available under the following subscription plans:
| Plan | Price | Monthly Verifications |
|---|---|---|
| Free | $0 / month | 200 |
| Starter | $29 / month | 10,000 |
| Growth | $79 / month | 50,000 |
| Scale | $199 / month | 250,000 |
Verification counts reset at the beginning of each billing cycle. Unused verifications do not roll over to the next month. We reserve the right to modify pricing with 30 days' notice.
Paid subscriptions are billed monthly through Stripe. By subscribing to a paid plan, you authorize us to charge your payment method on a recurring monthly basis until you cancel.
You agree to use the Service only for lawful purposes and in accordance with these Terms. You must not use the Service to:
API requests are subject to a rate limit of 10 requests per second per account. Exceeding this limit will result in HTTP 429 (Too Many Requests) responses. Persistent abuse of rate limits may result in temporary or permanent suspension of your account.
We reserve the right to adjust rate limits at any time. Higher rate limits may be available on custom enterprise plans — contact support@mailcaff.com for details.
We strive to maintain high availability but the Service is provided on a best-effort basis. We do not guarantee any specific uptime percentage or service level agreement (SLA) at this time. The Service may be temporarily unavailable due to:
We will make reasonable efforts to notify users of planned downtime in advance. We are not liable for any damages resulting from service interruptions.
When you submit email addresses for verification, we process them to return a verification result. We may temporarily cache results to improve performance and reduce redundant lookups. We do not sell, share, or disclose the email addresses you submit to any third party.
For more information about how we collect, use, and protect your personal data, please refer to our Privacy Policy.
The Service, including its design, API, documentation, and underlying technology, is the intellectual property of Mailcaff and is protected by applicable copyright, trademark, and other intellectual property laws. These Terms do not grant you any rights to our trademarks, logos, or brand assets.
You retain ownership of any data you submit to the Service. By using the Service, you grant us a limited, non-exclusive license to process your submitted data solely for the purpose of providing the Service.
We reserve the right to suspend or terminate your account at any time, with or without notice, if we determine in our sole discretion that you have violated these Terms. Grounds for termination include, but are not limited to:
Upon termination, your access to the Service will be revoked and your API keys will be deactivated. We are not obligated to provide a refund for any remaining subscription period following a termination for cause.
You may delete your account at any time through the dashboard or by contacting support@mailcaff.com.
THE SERVICE IS PROVIDED "AS IS" AND "AS AVAILABLE" WITHOUT WARRANTIES OF ANY KIND, WHETHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT. WE DO NOT WARRANT THAT:
Email verification is inherently imperfect. Mail servers may respond differently over time, and results can change based on external factors outside our control. You acknowledge this and agree to use verification results as one input in your decision-making, not as a sole determinant.
TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, MAILCAFF AND ITS OFFICERS, DIRECTORS, EMPLOYEES, AND AGENTS SHALL NOT BE LIABLE FOR ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, OR PUNITIVE DAMAGES, INCLUDING BUT NOT LIMITED TO:
IN NO EVENT SHALL OUR TOTAL LIABILITY TO YOU FOR ALL CLAIMS ARISING OUT OF OR RELATING TO THESE TERMS OR THE SERVICE EXCEED THE AMOUNT YOU PAID TO MAILCAFF IN THE TWELVE (12) MONTHS PRECEDING THE EVENT GIVING RISE TO THE CLAIM, OR ONE HUNDRED EUROS (EUR 100), WHICHEVER IS GREATER.
You agree to indemnify, defend, and hold harmless Mailcaff and its officers, directors, employees, and agents from and against any claims, liabilities, damages, losses, and expenses (including reasonable legal fees) arising out of or in any way connected with:
We may update these Terms from time to time. When we make material changes, we will notify you by email or by posting a prominent notice on the Service at least 14 days before the changes take effect. Your continued use of the Service after the changes take effect constitutes your acceptance of the revised Terms.
We encourage you to review these Terms periodically to stay informed about your rights and obligations.
These Terms are governed by and construed in accordance with the laws of the Netherlands, without regard to its conflict of law provisions. Any disputes arising out of or relating to these Terms or the Service shall be resolved exclusively by the competent courts in the Netherlands.
Before initiating any legal proceedings, you agree to attempt to resolve any dispute informally by contacting us at support@mailcaff.com. We will attempt to resolve the dispute within 30 days.
If you have any questions about these Terms, please contact us at support@mailcaff.com.