I. Product Overview
ZTmail: S/MIME encryption for everybody, automated. AI, your key.
The world's first email client with automated S/MIME certificate management + AI assistant. Engineered in Shenzhen, China.
Based on S/MIME international standards and China SM2 standards, it supports RSA, SM2, PQC algorithms for seamless encrypted interoperability with all major email clients. Automated email certificate application and configuration enable zero-threshold end-to-end encryption. It allows flexible integration with any AI model.
II. Core Features
- Automatic Encryption: Every email is end-to-end encrypted by default, using RSA or SM2 algorithms to guarantee confidentiality throughout the email lifecycle.
- Digital Signatures: Every email is digitally signed by default to prove sender identity trustworthiness and protect content integrity.
- AI Assistant: Choose your AI model, bring your own API key, and control your AI assistant. Let AI assist with drafting, polishing, translating, summarizing, and calendar extraction.
- Identity Choice & Display: Choose which identity to send emails, and clearly view sender identity levels (T1 / T2 / T3 / T4) on incoming mail. Higher levels represent higher trustworthiness.
- Multi-Account Management: Supports centralized management of multiple email accounts with unified automated encryption.
- Cross-Platform Support: Supports Windows, macOS, and Linux, with iOS and Android versions coming soon.
III. Product Editions
ZTmail provides three main product editions to meet diverse user requirements:
💡 For detailed pricing, please visit Editions & Pricing →
IV. Trusted Identity Edition — Three Sub-Products
The Trusted Identity Edition is divided into three sub-products according to identity validation level. Higher identity levels provide greater credibility to recipients.
💡 You are purchasing the "qualification to display your identity," not just a certificate. The system presents your trusted identity to recipients through automated, tamper-proof digital signatures.
V. Global Eco Edition — Two Product Lines
The Global Eco Edition solves the issue where third-party email clients like Outlook and Thunderbird display untrusted signature warnings. Two product lines are available:
Product Line 1: Value Edition (Recommended, Cost-Effective)
Combines International MV Certificates with ZoTrus Identity Certificates to achieve "Global Interoperability" and "Trusted Identity Display" at minimal cost.
Product Line 2: International Edition
Uses high-level certificates issued by international CAs, with identity verification performed directly by international CAs.
💡 For detailed pricing, please visit Editions & Pricing →
VI. Edition Comparison
RSA Interoperability
RSA Interoperability
Global Trusted Interoperability
Auto-decrypt RSA encrypted emails
Auto-decrypt RSA encrypted emails
Auto-decrypt RSA encrypted emails without signature warnings
Supports SM2 Algorithms
Fully Compliant (IV/OV/SV)
Fully Compliant (IV/OV/SV)
VII. Technical Architecture
Built on an integrated client-cloud zero trust architecture, adhering to minimal cloud dependency for ZTmail clients:
- Keys are generated locally on the client; CSRs are submitted automatically for certificate application and issuance, and private keys never leave the device.
- Upon receiving a certificate signing request, ZoTrus Cloud CA System sends a verification code to the user's email address. ZTmail recognizes this special email and reply to for email control validation according to RFC8823 for RSA certificates, and according to China ACME standard for SM2 certificates. ZTmail automatically retrieves and deploys these certificates.
- Users' sensitive data including private keys, contacts, and calendar items are encrypted using a user-configured password, manually backed up to their own mailbox, and manually synced to ZTmail on other devices.
- No manual public key exchange is required. ZTmail connects automatically to ZoTrus certificate directory service to fetch recipient public key certificates, solving the key exchange challenge.
VIII. System Requirements
- Windows: Windows 10/11 and above
- Linux: Ubuntu 20.04 / Fedora 34 / Debian 11 / Kylin V2403 and above
- macOS: macOS 11 (Big Sur) and above (Intel / Apple Silicon) (Coming Soon)
- iOS and Android versions coming soon