Privacy Policy

1. Information We Collect

Account Information

When you create an account, we collect your name, email address, and a password. If you configure a mailbox, we also collect your IMAP server credentials (username, password, server address, and port). If you connect via Gmail OAuth 2.0 or Microsoft Graph OAuth 2.0, we receive and store encrypted access and refresh tokens — your email provider password is never shared with us.

Email Metadata

We process email messages to classify them into categories (e.g., Safe Email, Newsletter, Promotional, Spam). We retain only the message ID, classification category, confidence score, and action taken to prevent duplicate processing and provide usage statistics. We do not store the content of your emails.

Email Modification

When a message is classified as unwanted and moved, Post Guard AI injects a visible warning banner into the email's HTML and plain-text body before relocating it. This modification is performed in your mailbox (via IMAP APPEND, Gmail API messages.insert, or Microsoft Graph API) and is visible only to you. The original message is removed after the bannered copy is created. If you disagree with the classification, dragging the email back to your inbox automatically whitelists that sender's domain.

Usage Data

We may automatically collect certain information when you access the service, including your IP address, browser type, operating system, referring URLs, and pages viewed. This information is used to maintain and improve the service.

2. How We Use Your Information

• To provide, operate, and maintain the Post Guard AI service
• To classify and organize your incoming email messages
• To authenticate your identity and manage your account
• To communicate with you about your account or the service
• To detect, prevent, and address technical issues or security threats
• To comply with legal obligations

3. AI and Email Processing

Post Guard AI uses artificial intelligence to classify email messages. The AI model runs entirely on our private cloud infrastructure — no email content is sent to third-party AI services. Email bodies exceeding 24,000 characters are automatically truncated before classification. Email content processed by the AI is never used to train models. Classification is performed in real time, and no email body content is retained after processing.

Inbox monitoring uses IMAP IDLE push notifications, Gmail API adaptive polling (30 s–5 min intervals), or Google Cloud Pub/Sub push notifications depending on your connection type. When Pub/Sub is configured, Google delivers a notification to our webhook endpoint indicating that new mail is available — the notification contains only your mailbox identifier, not email content. All message content is then fetched directly from the Gmail API over HTTPS.

4. Data Security

We implement reasonable administrative, technical, and physical safeguards to protect your personal information:

• One-way password hashing: User account passwords are hashed using PBKDF2-HMAC-SHA512 with 600,000 iterations and a unique random salt. Passwords can never be recovered — only verified. Existing accounts using the previous encryption method are migrated transparently on next login.
• Credential encryption: IMAP passwords, OAuth access and refresh tokens, and TOTP two-factor secrets are encrypted at rest using AES-256-GCM with PBKDF2-derived keys.
• Default password enforcement: On first admin login, if the default password is still in use, a mandatory password change is required before the application can be used.
• Account lockout: After repeated failed sign-in attempts, the account is temporarily locked to prevent brute-force attacks.
• Rate limiting: Sign-in requests are rate-limited per IP address to prevent automated credential stuffing.
• Session invalidation: All user sessions are automatically invalidated when the application restarts, requiring re-authentication.
• TLS certificate validation: In production, all IMAP connections validate server TLS certificates against the system trust store. Connections to servers with invalid or self-signed certificates are rejected.
• Two-factor authentication: User accounts support TOTP-based multi-factor authentication, adding an extra layer of protection beyond your password.
• OAuth 2.0: Gmail and Microsoft 365 users connect via their provider's consent screen. We never receive or store your email provider password — only scoped access tokens that can be revoked at any time.
• Database resilience: Transient database failures are automatically retried with exponential backoff, ensuring classification and security data is never silently lost. Permanent errors are logged with diagnostic details for investigation.

However, no method of transmission over the Internet or electronic storage is completely secure, and we cannot guarantee absolute security.

5. Data Retention

We retain your account information for as long as your account is active or as needed to provide you with the service. Email message IDs and classification statistics are retained to prevent duplicate processing and to provide you with usage reports. You may request deletion of your account and associated data at any time by contacting us.

6. Disclosure of Your Information

We do not sell, trade, or rent your personal information to third parties. We may disclose your information in the following circumstances:

• Legal Requirements: If required to do so by law or in response to valid requests by public authorities (e.g., a court or government agency).
• Protection of Rights: If we believe disclosure is necessary to protect our rights, your safety, or the safety of others, investigate fraud, or respond to a government request.
• Service Providers: We may share information with third-party vendors who perform services on our behalf, subject to confidentiality obligations.

7. Cookies and Tracking Technologies

We may use cookies and similar tracking technologies to maintain your session and remember your preferences. You can instruct your browser to refuse all cookies or to indicate when a cookie is being sent. However, some features of the service may not function properly without cookies.

8. Third-Party Links

Our service may contain links to third-party websites or services that are not operated by us. We have no control over, and assume no responsibility for, the content, privacy policies, or practices of any third-party sites or services.

9. Children’s Privacy

Our service is not intended for use by anyone under the age of 13. We do not knowingly collect personal information from children under 13. If we become aware that we have collected personal information from a child under 13, we will take steps to delete that information.

10. Your Rights

Depending on your jurisdiction, you may have the right to:

• Access the personal information we hold about you
• Request correction of inaccurate information
• Request deletion of your personal information
• Object to or restrict certain processing of your data
• Request portability of your data

To exercise any of these rights, please contact us using the information provided below.

11. Changes to This Privacy Policy

We may update this Privacy Policy from time to time. We will notify you of any changes by posting the new Privacy Policy on this page and updating the “Effective Date” at the top. You are advised to review this Privacy Policy periodically for any changes.