(1) What is ZTmail?
The world's first email client with automated encryption + bring-your-own AI. Every email is automatically encrypted and digitally signed by default — zero manual effort required.
(2) What does "S/MIME encryption for everybody, automated. AI, your key." mean?
This is the ZTmail promise in one sentence:
One clicks to enable. From then on, every email you send is automatically encrypted and digitally signed.
(3) How long is the free edition valid?
Forever. All core features — automated encryption, digital signatures, AI integration — are completely free, no payment required.
(4) What makes ZTmail different from regular email clients?
Regular clients just send and receive emails. ZTmail automatically encrypts, digitally signs, displays sender identity, and provides an AI assistant to help you process emails.
(5) Does ZTmail store my data?
No. ZTmail is just a tool. Your emails stay on your own mail server, your private keys stay on your device. ZoTrus cloud stores no user email content whatsoever.
(6) Where do the encrypting certificates come from?
ZTmail automatically applies for and configures S/MIME email certificates for you — fully automated. Zero user action required.
(7) Which operating systems are supported?
Windows, macOS, and Linux are fully supported. iOS and Android versions coming soon.
(8) Why does ZTmail emphasize "trusted identity"?
Traditional email senders can be forged at will. ZTmail uses digital signatures and identity validation so recipients can instantly see "who sent it and with what identity."
(9) Which encryption algorithms does ZTmail support?
Both international standard RSA and China's national standard SM2. Users can freely switch the default algorithm in settings. PQC algorithms will be supported in the future.
(10) Is ZTmail compatible with other email clients?
Fully compatible. Based on the S/MIME international standard, ZTmail interoperates seamlessly with Outlook, Thunderbird, Apple Mail, and all other S/MIME-compatible clients.
(1) What plans does ZTmail offer?
Three plans: Free (forever free), Trusted Identity Edition (US$7.98~15.98/year), and Global Eco Edition (US$13.98~48.98/year).
(2) What's the core difference between the three plans?
Free displays T1 identity (email only). Trusted Identity Edition displays T2 / T3 / T4 trusted identity. Global Eco Edition adds no digital signature warnings in Outlook and other third-party clients.
(3) Is the Free plan sufficient?
If you only need automated encryption and digital signatures, Free is enough. If you want recipients to see your name or organization, upgrade to Trusted Identity Edition.
(4) Which plan should I choose?
Choose Free for basic encryption. Choose Trusted Identity Edition to let recipients see your identity. Choose Global Eco Edition if your recipients use Outlook and you want to eliminate signature warnings.
(5) Can I get a refund after purchase?
Yes. The paid service from ZTmail offers a 7-day no-questions-asked refund. Once refunded, your certificate will be immediately revoked, and all previously sent signed and encrypted emails will show a "certificate revoked" notice to recipients, making the digital signatures permanently invalid. It's recommended to try the free edition before buying. Revoking a paid certificate won’t affect the use of free certificates, but you might need to manually set the default encrypting certificate if your default certificate was the revoked paid one.
(1) What products are in Trusted Identity Edition?
Three products: Individual Identity Edition, Organization Identity Edition, and Employee Identity Edition.
(2) What does Individual Identity Edition display?
T2 · Individual Validated. Recipients see your real name. Validates your personal identity.
(3) What does Organization Identity Edition display?
T3 · Organization Validated. Recipients see your organization name. Validates that you are an employee of that organization.
(4) What does Employee Identity Edition display?
T4 · Sponsor Validated. Recipients see both your organization name and your name. Double confirmation, the highest level of trust.
(5) How do I choose among the three?
Choose Individual Identity Edition to let recipients know who you are. Choose Organization Identity Edition to let recipients know you are an employee of that organization. Choose Organization Employee Identity Edition when both organization and individual identity need to be confirmed.
(1) What products are in Global Eco Edition?
Two product lines: Value Edition and International Edition, each containing four sub-products: Basic, Individual, Organization, and Employee — 8 products total.
(2) What's the difference between Value Edition and International Edition?
Value Edition = International MV certificate + ZoTrus identity certificate (identity validated by ZoTrus). International Edition uses high-level identity certificates validated and issued by global CAs.
(3) What identity levels do the four sub-products correspond to?
Basic = T1 (Mailbox Validated only). Individual = T2 (Individual Validated). Organization = T3 (Organization Validated). Employee = T4 (Sponsor Validated).
(4) How do I choose among Value Edition products?
Choose Basic if you only need global interoperability. Choose Individual to display your personal identity. Choose Organization to display your organization identity. Choose Employee for double confirmation.
(5) How do I choose among International Edition products?
Choose Basic if you only need global CA interoperability. Choose Individual for global CA individual validation. Choose Organization for global CA organization validation. Choose Employee for global CA sponsor validation.
(1) How do I choose an identity when composing?
Click the sender identity selector next to the From field. Choose T1 / T2 / T3 / T4. Use T1 for daily communication, T2 for personal communication, T3 when communicating as an employee of an organization, T4 for double confirmation.
(2) How do I identify the sender's identity when receiving emails?
Every email in the message list carries an identity icon (T1 / T2 / T3 / T4). Click the icon to view detailed validated identity information.
(3) How do I choose an identity when replying?
The identity selection works the same way as when composing — choose the identity level you want to use for this reply from the sender identity selector.
(4) What does a higher identity level mean?
The higher the identity level, the more complete the identity information recipients see, and the higher the trust.
(5) Can Outlook users decrypt emails have encrypted by ZTmail?
Yes. Users just need to export the email certificate automatically configured by ZTmail and install it on their Windows system. Outlook will automatically decrypt emails encrypted with the RSA algorithm. However, it cannot decrypt emails encrypted with the SM2 algorithm.
(1) How do I enable AI features?
Enter your preferred AI service provider's API key (e.g., OpenAI, DeepSeek) in settings to enable the AI assistant.
(2) What can the AI assistant do?
Draft, polish, shorten, expand, proofread, and translate emails. It can also summarize long emails, extract schedule items, and detect fraudulent emails with one click.
(3) How does AI fraud detection work?
Once AI is configured, the system automatically analyzes sender anomalies and email content. When suspicious emails are detected, it displays security warnings at the top.
(4) Does the AI read my email content?
Yes, the AI does read your email content in order to process it, but only when you actively use an AI feature. Requests are sent directly from your computer to your chosen AI provider; they do not pass through ZoTrus server. Whether to allow AI to process encrypted emails is entirely your choice, it is configurable in settings.
(5) Is AI functionality free?
AI features are free to use. However, you are responsible for any costs incurred from calling your AI service provider's API.
(1) How does ZTmail help me detect fraudulent emails?
Through identity display for active judgment and AI assistant for automatic anomaly detection and proactive warnings.
(2) What indication is shown for emails without digital signatures?
The message list clearly marks them with "⚠️ Identity Not Verified" to remind you to proceed with caution.
(3) What issues can AI fraud detection identify?
Sender domain impersonation, urgent transfer requests, suspicious links, unusual attachments, requests for sensitive information, and more.
(4) What should I do if I receive a suspicious email?
Do not click links or provide personal information. ZTmail displays specific risks and recommendations at the top of the suspicious email.
(5) Which is more reliable — identity display or AI detection?
Both work best together. Identity display lets you "actively judge," while AI detection provides "passive defense." Double protection.