SJ-Mail Privacy Policy

1. How We Collect and Use Your Personal Information

SJ-Mail is a local-first desktop email client. To provide mail sending and receiving, local management, and AI-enhanced services, we need to access and process relevant data in the following scenarios:

• Local mail storage: your mail (body, sender, recipients, subject, date, attachment metadata, etc.) is downloaded from the mail server and stored in a SQLite database on your local device, for offline reading, search, archiving, and management.
• Local credential encryption: passwords or authorization codes you enter when configuring email accounts are stored locally encrypted with AES-256-GCM, never written to disk or transmitted in plaintext.
• AI service request processing: when you actively use AI features (smart chat, compose, translate, summarize, daily briefing, profile analysis, attachment analysis, etc.), the relevant mail content undergoes real-time inference via the SJ-AI service to generate results. Processing completes within the service request.
• Technical data: your operating system type and version, app version, locally generated operation logs during use, etc., used for service operation, troubleshooting, and product improvement.

1.1 Special Notes on the AI Service (SJ-AI)

SJ-Mail's AI capabilities are driven by Shujian AI's self-developed SJ-AI protocol, using a "server-side orchestration + client-side execution" architecture. The SJ-AI service may be compute-supported by Shujian AI or its designated AI service provider(s). When you use AI features, your data is handled under the following rules:

• On-demand processing: AI processes relevant mail content only when you actively initiate a request; it does not continuously scan or upload all mail in the background.
• Not used for training: we have taken technical configuration measures to disable the data-optimization switch used for training; your mail content will not be used for any model training or fine-tuning.
• Local security boundary: AI can invoke local tools (MCP framework) to perform mail operations, but sensitive actions such as sending, deleting, flagging, saving contacts, and sending drafts always require your manual approval (approval timing out after 5 minutes counts as rejection).
• Attachment handling: for AI attachment analysis, images are read locally as data URIs; raw file paths are not exposed.

Responsibility allocation: when the SJ-AI service is compute-supported by a designated third-party AI provider, that provider acts as an independent data processor whose processing is governed by its own privacy policy. We recommend reviewing the relevant provider's privacy policy to understand its data handling rules.

1.2 User Profiles and Personalization

To generate content better suited to your style and needs, the AI profile feature may perform characteristic analysis based on your sent and received mail content and your organizational structure information. This process follows the principles of necessity, explicit purpose, and transparency; it is used only to improve the quality of the mail assistant service and will not profile based on sensitive information such as race, ethnicity, politics, religion, health, sex life, or sexual orientation.

2. Data Storage and Local Encryption

• Local-first storage: mail, settings, and credentials are stored preferentially on your local device; you can archive mail locally at any time to keep it long-term off the server.
• Encrypted storage: account passwords and AI keys are stored in the local database encrypted with AES-256-GCM; encryption keys are backed by the operating system's key ring or secure storage mechanism.
• Safe rendering: mail HTML is sanitized via DOMParser before rendering, preventing XSS and phishing script execution.
• Audit logs: operation logs rotate daily and are stored in the user data directory; mail content is not uploaded to remote logs.

3. Data Sharing and Disclosure

Except as otherwise stated in this policy (such as real-time processing by the SJ-AI service during AI requests), we do not share your mail data with any third party unless one of the following applies:

• as required by laws and regulations or lawful orders of competent government authorities;
• as necessary to safeguard the legitimate interests of users or the public interest;
• in emergencies, to protect the personal safety of users or others;
• in the event of a merger, acquisition, or other asset transaction, your information may be transferred as part of the transaction assets, but we will ensure the information continues to be governed by this policy or notify you of subsequent handling.

We may share necessary information with service providers to complete payment transactions or provide technical services, but such providers may use your information only to the extent necessary to provide the service.

4. Data Security Measures

We use industry-standard security technologies to protect your personal information, including:

• Encryption: account credentials and AI keys stored with AES-256-GCM encryption; data in transit protected with SSL/TLS.
• Access control: strict access-control mechanisms; only authorized personnel may access server-side data.
• AI security boundary: tool definitions are provided by the client; the server stores no schema, reducing the attack surface; sensitive operations enforce local approval.
• Security audits: regular security audits and vulnerability scans; local operation logs rotate daily.

Despite the measures above, please understand that given the complexity of the internet environment, no security measure is 100% impregnable.

5. Data Retention

Your mail data is stored on your local device; you can manage it at any time via local archiving, deletion, and similar operations, and it is removed along with the app on uninstall (unless you choose to keep the archive directory). Mail content processed by the SJ-AI service is cached only briefly during real-time processing and deleted upon completion; it is not retained long-term and is not used for model training. User profile tags are retained only for the duration of the service we provide to you.

6. Your Rights

Under applicable laws and regulations, you enjoy the following personal-information rights:

6.1 Right to deletion

Because mail data is stored on your local device, you can delete mail, empty folders, or uninstall the app at any time to clear local data. For related information retained on the server, we will proactively delete it or delete it upon your request when any of the following occurs: the processing purpose has been achieved or is no longer necessary, the service is terminated, you withdraw consent, or we have processed it in violation of the law, among others.

6.2 How to exercise your rights

1. Request channel: you can submit requests to delete personal information, withdraw authorization, or cancel your account via our official email privacy@shujian-ai.com.
2. Handling process: after receiving a valid request, we will handle it in a timely manner in accordance with the law; if we decline, we will explain the reasons.

6.3 Withdrawing authorization and account cancellation

You may withdraw personal-information authorization or submit an account-cancellation request by email. After consent is withdrawn, we will no longer be able to provide the corresponding service, but this does not affect processing already performed based on the earlier authorization.

7. Protection of Minors

Our products and services are primarily intended for adults. If we proactively discover or are informed during operations that a user is a minor without valid guardian consent, we will immediately suspend or terminate service to that account and delete or anonymize the collected personal information in accordance with the law (except in the rare cases where retention is required by law).

8. Updates to This Privacy Policy

We may adjust this policy as our business develops and laws and regulations change. In the event of material changes, we will notify you via in-app notice, email, or announcement. Your continued use of the service constitutes acceptance of the modified policy; if you do not agree, you may stop using the service and clear your local data at any time.

9. Disclaimer

Regarding content accuracy: due to the inherent nature of AI technology, we cannot fully guarantee the absolute accuracy, completeness, or applicability of AI-generated content. You are responsible for exercising prudent independent judgment on AI-generated content and making necessary modifications and verification, and you bear the consequences of ultimately adopting and using such content.

Regarding force majeure: to the extent permitted by law, we are relieved of corresponding liability for service interruptions or data security incidents caused by force majeure, but we commit to taking reasonable remedial measures promptly after the event.

10. Contact Us

If you have any questions, comments, or suggestions about this privacy policy or the processing of your personal information, or wish to exercise your personal-information rights, please contact our privacy officer:

Email: privacy@shujian-ai.com  |  Business cooperation: sales@shujian-ai.com

We commit to responding to access requests within 15 days and to complaints within 24 hours.