Terms of Service

Effective date: 17 July 2026 · Castellum

These Terms govern your use of Castellum, a native desktop email client provided by Joan Marc Riera (sole trader), trading via riera.co.uk ("we", "us"). By installing or using Castellum you agree to these Terms.

1. The service

Castellum is software you run on your own device to access your own email accounts. It is local-first: it operates no cloud server that receives your mailbox content. Your use of your email providers (Gmail, Outlook, IMAP hosts, etc.) is also subject to *their* terms.

2. Licence

Castellum is currently in early access and provided free of charge. During early access, Castellum is provided free of charge. We grant you a personal, non-exclusive, non-transferable licence to use the app. We may introduce paid licensing in future; existing early-access terms for a given installed version will not be retroactively invalidated.

3. Acceptable use

You agree not to: reverse-engineer, redistribute, or resell the app except as permitted by its licence; use it to send spam or unlawful content; or use it to violate your email provider's terms or any applicable law.

4. Your data and privacy

Your email and related data stay on your device. Our handling of any data is described in the Privacy Policy at /privacy, which is incorporated by reference.

5. Third-party services

Castellum connects to services you choose (your email providers; and, if you purchase a licence, the payment processor Lemon Squeezy as Merchant of Record). We are not responsible for those third parties' availability or conduct.

6. Warranty disclaimer

Castellum is provided "as is" and "as available", without warranties of any kind, express or implied, including merchantability, fitness for a particular purpose, and non-infringement. We do not warrant that the app will be uninterrupted, error-free, or that it will not lose or fail to sync data. Keep your own backups of important mail.

7. Limitation of liability

To the maximum extent permitted by law, Joan Marc Riera (sole trader), trading via riera.co.uk is not liable for any indirect, incidental, special, consequential, or punitive damages, or for loss of data, profits, or goodwill, arising from your use of the app. Our total aggregate liability will not exceed the amount you paid for the app in the 12 months preceding the claim (which may be zero during free early access). Nothing here limits liability that cannot be limited by law (e.g. for death or personal injury caused by negligence, or fraud).

8. Termination

You may stop using the app at any time by uninstalling it. We may suspend or terminate the licence if you breach these Terms.

9. Changes

We may update these Terms; material changes will be posted at /terms with a new effective date. Continued use after changes means you accept them.

10. Governing law

These Terms are governed by the laws of England & Wales, United Kingdom, and disputes are subject to the courts of England & Wales, United Kingdom, without prejudice to any mandatory consumer-protection rights you have where you live.

11. Contact

Joan Marc Riera (sole trader), trading via riera.co.uk — info@castellummail.com