In short: Mailer is a private-beta desktop email client for Windows and Linux. Use it lawfully, keep your own backups, and review AI output before sending. The app is provided as-is during the beta, and mandatory consumer rights are not affected.
1. Acceptance
These Terms of Service ("Terms") form an agreement between you and Martin Kukal, U Valu 496, Nupaky, 25101, Czech Republic ("we", "us", or "our") for the use of the Mailer desktop application and this website. By installing, accessing, or using Mailer, you agree to these Terms. If you do not agree, do not use Mailer.
2. Private beta
Mailer is currently provided as a private beta. Features may change, break, or be removed without notice. Access may be limited, suspended, or revoked. We do not guarantee that the beta will be available for any particular period or that data formats will remain compatible.
Any fees, if introduced, will be agreed separately before you are charged. The beta is provided free of charge unless we agree otherwise in writing.
3. Licence and permitted use
Subject to these Terms, you receive a limited, non-exclusive, non-transferable, revocable licence to install and use Mailer for your personal or internal business purposes.
You may not redistribute, sublicense, sell, rent, or commercially exploit Mailer, or reverse engineer, decompile, or create derivative works from it, except where applicable law expressly permits it or we agree in writing. All rights not expressly granted are reserved.
4. Your accounts and credentials
You are responsible for the e-mail accounts, devices, passwords, OAuth grants, and AI API keys you use with Mailer. Keep your device and credentials secure. You must have the right to access every mailbox you connect.
Mailer stores credentials locally in an encrypted vault, but no system is perfectly secure. If you suspect unauthorised access, revoke the OAuth grant with your provider, change your passwords, and remove the account from Mailer.
5. Acceptable use
You agree not to use Mailer to:
- send spam, phishing, malware, or unlawful bulk mail;
- harass, threaten, defraud, or deceive others;
- access a mailbox or data you are not authorised to access;
- violate the terms of your mail provider, AI provider, or applicable law;
- interfere with the security or operation of Mailer or third-party services.
We may suspend access if we reasonably believe you are using Mailer in a way that creates a security, legal, or abuse risk.
6. Third-party services
Mailer connects to services operated by others, including Google, Microsoft, your mail provider, AI providers, MyMemory, GitHub, and OpenPGP keyservers. Those services have their own terms, privacy policies, limits, and availability. We are not responsible for them.
Mailer is not affiliated with Google LLC, Microsoft Corporation, or any other provider. Google, Gmail, Microsoft, Outlook, and Microsoft 365 are trademarks of their respective owners.
7. AI features
AI features are optional and depend on the provider you configure. AI output can be inaccurate, incomplete, or inappropriate. You are responsible for reviewing AI-generated text, classifications, translations, and suggestions before relying on them or sending them.
Do not send confidential, sensitive, or regulated data to an AI provider unless you are authorised to do so and accept that provider's terms. You are responsible for the costs and limits of your AI account.
8. No warranty
Mailer is provided "as is" and "as available" during the private beta. To the maximum extent permitted by law, we disclaim warranties of merchantability, fitness for a particular purpose, non-infringement, and uninterrupted or error-free operation.
Mailer is not a backup service. Keep independent backups of important mail, attachments, keys, and settings. We are not responsible for data loss caused by device failure, provider deletion, sync errors, beta changes, or user actions.
Nothing in these Terms excludes or limits any warranty or right that cannot be excluded or limited under mandatory law, including consumer protection law.
9. Limitation of liability
To the maximum extent permitted by law, we are not liable for indirect, incidental, special, consequential, or punitive damages, or for loss of profits, revenue, data, goodwill, or business opportunity, arising from or related to Mailer or these Terms.
Our total liability for direct damages arising from or related to Mailer or these Terms is limited to the amount you paid us for Mailer in the twelve months before the event giving rise to the claim, or CZK 1,000 if you paid nothing.
Nothing in these Terms limits liability for intentional misconduct, gross negligence, death or personal injury, or any liability that cannot be limited under mandatory law. If you are a consumer, your mandatory statutory rights are not affected.
10. Privacy
Our Privacy Policy explains how Mailer processes personal data, including Google user data, OAuth tokens, AI features, and local storage. It forms part of these Terms.
11. Intellectual property
Mailer, its name, logo, code, documentation, and website content are owned by us or our licensors and are protected by intellectual property laws. These Terms do not transfer ownership to you.
Your mail, attachments, and other content remain yours. You grant us only the limited rights needed to provide the features you request, such as processing a message locally or sending it to a provider you configured.
12. Changes and termination
We may update these Terms from time to time. The effective date at the top of this page will change, and material changes will be announced in the app or on this website. Continued use after the effective date means you accept the updated Terms.
You may stop using Mailer at any time. We may suspend or terminate access to the private beta if you breach these Terms, if required by law, or if we discontinue the beta. Sections that by their nature should survive termination — including intellectual property, disclaimers, liability limits, and governing law — will survive.
13. Governing law and disputes
These Terms are governed by the laws of the Czech Republic, without regard to conflict-of-law rules. Courts in the Czech Republic have jurisdiction, subject to mandatory rules that protect consumers, including rules that allow consumers to bring proceedings in their country of residence.
Before starting a dispute, please contact us at martin@kukal.cz so we can try to resolve the issue.
14. Contact
Martin Kukal
U Valu 496, Nupaky, 25101, Czech Republic
martin@kukal.cz
These Terms are available in English and Czech. For users in the Czech Republic, the Czech version prevails if there is a conflict.