This Privacy Policy explains how Nestiel collects, uses, stores, shares, and protects your information. Nestiel is independently developed and operated by Zhang Ze, an individual developer. We take privacy seriously and follow the requirements of applicable laws such as the Personal Information Protection Law and the Cybersecurity Law of the People's Republic of China; for users outside mainland China, we also follow generally accepted international privacy practices.
Please note the split of responsibility between the hosted edition and self-hosted deployments: in the hosted edition we operate, we act as the personal information processor (data controller) for the relevant personal information; in self-hosted deployments, you decide how data is processed and are the data controller — we do not access data in your instance, and the descriptions in this policy about 'we collect / store information' do not apply to self-hosted deployments.
1. Information we collect
In the hosted edition, we may collect and process the following information to deliver the service:
- Account information: the email address you use to log in, one-time-code records, and session credentials;
- Organization and member information: org names, member emails, roles, and invitation relationships you create;
- Email data: metadata of the mail you send and receive (sender, recipients, cc, subject, timestamps, delivery events, etc.), message bodies, and attachments;
- Configuration you provide: the sending domain, Resend API key, webhook secret, and (when you enable AI features) the LLM provider's API key, base URL, and model name;
- Technical and log information: access times, IP addresses, browser and device info used for security and troubleshooting.
2. How we use information
We use the above information only as necessary to provide and improve the service, including:
- Delivering core capabilities: send/receive, conversation threading, separate sending, scheduled send, and more;
- Account login, authentication, and multi-tenant isolation;
- Invoking LLMs to complete translation, drafting, and per-recipient personalization when you enable those features;
- Protecting service security, troubleshooting, and preventing abuse;
- Meeting obligations required by applicable laws.
3. Third-party sharing and processors
To deliver core capabilities, we transmit relevant data to the following third-party services within necessary limits and strictly for the purposes below:
- Resend: for sending, receiving, and processing delivery events — the corresponding message content and addresses pass through it;
- Object storage provider (e.g., Aliyun OSS): for storing email attachments;
- Email service (a QQ Mail SMTP): for delivering login one-time codes;
- LLM provider: when you enable email translation, AI drafting, or per-recipient personalization, the relevant text is sent to the provider you configure for processing.
4. Cross-border transfer and sharing limits
Some of the third-party services listed above may have servers outside mainland China (for example, some LLM providers or overseas nodes). When you use the relevant features, your data may be transferred and processed outside mainland China. We work to ensure such transfers comply with applicable law; by enabling those features, you acknowledge and consent to the necessary cross-border transfers involved.
Beyond what is necessary to deliver these features, obtained with your consent, or required by law, we do not sell or rent your personal information to any third party.
5. Storage and security
Email metadata, conversations, and org member information are stored in a PostgreSQL database; email attachments are stored in object storage. We apply reasonable technical and organizational measures to protect your information.
Please note: under a 'trusted runtime' design assumption, sensitive credentials (such as the Resend API key, webhook secret, and LLM API key) are currently stored in plaintext in the database. The service does not provide end-to-end encryption. We recommend deploying and using the service only in trusted, controlled environments and managing access permissions carefully.
Inbound email attachments are fetched from Resend on demand and may expire under its retention policy; attachments on email you have sent are persisted to your object storage.
6. Cookies and local storage
To maintain your login state, the hosted edition stores the necessary session tokens in your browser's localStorage. The marketing site itself is primarily static and does not track your identity. You can clear your browser storage to log out or remove the related data.
7. Data retention and deletion
We retain your information only as long as necessary to provide the service. You can delete conversations, emails, or your account; after account deletion or removal of the relevant org / mailbox, we cascade related data according to system logic. Some data may be retained for a reasonable period due to legal obligations or backup mechanisms.
8. Your rights
To the extent permitted by applicable law, you have the following rights over your personal information; contact us via the email below to exercise them:
- Access and copy: understand and obtain the personal information we process about you;
- Correction and completion: request that inaccurate or incomplete information be corrected;
- Deletion: request deletion of your personal information under qualifying conditions;
- Withdraw consent: withdraw previously given consent for specific processing (e.g., AI features, cross-border transfer);
- Delete your account: stop using the service and delete your account at any time.
9. Minors
The service is designed for users with full legal capacity and is not primarily aimed at minors. If you are a minor, please use the service with the consent and guidance of a guardian. If we discover we have collected minors' personal information without a guardian's consent, we will delete it promptly.
10. Self-hosted deployments
In self-hosted deployments, you deploy and operate the software on your own infrastructure and are the data controller for the relevant data. We do not access, store, or process any data in your instance, and cannot respond to data-subject requests on your behalf. You should draft and publish your own privacy policy for your users and are responsible for the compliance of your data processing activities.
11. Policy updates
We may update this Privacy Policy from time to time. Updates are published on the website and take effect from the date of publication. For significant changes, we will use appropriate means to give notice. Continuing to use the service after an update constitutes acceptance of the updated policy.
For questions about privacy or to exercise your rights, contact:
15046644304@163.com