Terms of Service

Last updated: 8/21/2025

1. Acceptance of Terms

By accessing and using SubjectLine.app ("the Service"), you accept and agree to be bound by the terms and provision of this agreement. If you do not agree to abide by the above, please do not use this service.

2. Description of Service

SubjectLine.app provides an AI-powered subject line testing and optimization platform that allows users to test email subject lines and receive AI-generated suggestions to improve email campaign engagement. The Service includes access to our web-based platform, AI recommendations, voting system, and related services.

3. User Accounts

To access certain features of the Service, you must create an account. You are responsible for:

  • Maintaining the confidentiality of your account credentials
  • All activities that occur under your account
  • Providing accurate and complete information
  • Notifying us immediately of any unauthorized use
  • Ensuring your subject line content complies with our acceptable use policy

4. Subscription and Billing

The Service offers both free and Pro subscription tiers. By subscribing to Pro, you agree to:

  • Pay all fees associated with your Pro subscription
  • Provide accurate billing information
  • Authorize recurring charges to your payment method
  • Cancel your subscription before the next billing cycle to avoid charges
  • Understand that free accounts are limited to 1 subject line test

5. Acceptable Use

You agree not to use the Service to:

  • Violate any applicable laws or regulations
  • Infringe on intellectual property rights
  • Test subject lines containing harmful, offensive, or inappropriate content
  • Attempt to gain unauthorized access to our systems
  • Interfere with the proper functioning of the Service
  • Use the Service for spam or malicious email campaigns

6. Intellectual Property

The Service and its original content, features, and functionality are owned by SubjectLine.app and are protected by international copyright, trademark, patent, trade secret, and other intellectual property laws. You retain ownership of your subject line content, while we own the AI recommendations.

7. Privacy Policy

Your privacy is important to us. Please review our Privacy Policy, which also governs your use of the Service, to understand our practices regarding your subject line data and AI interactions.

8. Termination

We may terminate or suspend your account and access to the Service immediately, without prior notice, for any reason, including breach of these Terms of Service or inappropriate use of the AI features.

9. Limitation of Liability

In no event shall SubjectLine.app, nor its directors, employees, partners, agents, suppliers, or affiliates, be liable for any indirect, incidental, special, consequential, or punitive damages, including without limitation, loss of profits, data, use, goodwill, or other intangible losses related to email campaign performance or AI recommendations.

10. Disclaimers

The Service is provided on an "AS IS" and "AS AVAILABLE" basis. SubjectLine.app makes no warranties, expressed or implied, and hereby disclaims all warranties, including without limitation, implied warranties of merchantability and fitness for a particular purpose. AI recommendations are suggestions only and do not guarantee improved email performance.

11. Governing Law

These Terms shall be interpreted and governed by the laws of the United States, without regard to its conflict of law provisions.

12. Changes to Terms

We reserve the right to modify or replace these Terms at any time. If a revision is material, we will provide at least 30 days notice prior to any new terms taking effect.

13. Contact Information

If you have any questions about these Terms of Service, please contact us at:

Email: legal@subjectlines.app
Website: https://subjectlines.app