Privacy Policy

Last updated: May 2026

Inbox Search ("we", "our", "the add-in") is an Outlook add-in developed and operated by an individual developer. It uses on-device AI to provide fast, semantic email search across your mailbox. This policy explains what data we access, how it is used, and your rights as a user.

1. Who We Are

Inbox Search is an independent add-in developed by a solo developer. It is not affiliated with Microsoft Corporation. For any privacy-related enquiries, contact us at [email protected].

2. Data We Access

To build and search your local email index, the add-in accesses the following data from your Microsoft 365 account via the Microsoft Graph API, solely on your device:

This data is processed on your device to build and maintain a local search index. None of it is transmitted to our servers.

3. How Data Is Processed

All AI processing happens entirely on your device. The add-in loads a small AI model from our servers and runs it locally inside Outlook's browser environment using Transformers.js and WebAssembly. Your email content is never sent to our servers or to any third-party AI service.

The add-in creates embedding vectors (numerical fingerprints) and TF-IDF keyword indices for each email. These are stored locally in your browser's IndexedDB storage and used to rank search results. No email text is stored on any external server.

4. Data Storage and Retention

IndexedDB (search index): The add-in stores the following data locally in your browser's IndexedDB:

This index remains entirely on your device and is never transmitted to our servers. It is cleared when you uninstall the add-in or clear your browser storage.

localStorage (authentication tokens): The Microsoft Authentication Library (MSAL) stores OAuth tokens in your browser's localStorage. This is standard browser-based OAuth behaviour. These tokens contain no email content and are scoped to the add-in's domain.

5. Legal Basis for Processing (GDPR)

If you are located in the European Economic Area (EEA), our legal basis for accessing your mailbox data is legitimate interests (Article 6(1)(f) GDPR): specifically, to provide the email search functionality you have explicitly chosen to use. We process the minimum data necessary for this purpose and do not use it for any other purpose.

6. Microsoft Graph API and Authentication

The add-in uses Microsoft's OAuth 2.0 identity platform (Azure Active Directory) to authenticate you. We request only the minimum Graph API permissions needed:

7. Data We Do Not Collect

8. Third-Party Services

The AI model is an open-source sentence-transformer sourced from Hugging Face under an Apache 2.0 licence. It is self-hosted on our own infrastructure and cached in your browser after the first load. No third-party AI service is contacted during normal use.

The add-in communicates with Microsoft Graph (to read email content for indexing) and Microsoft Azure Active Directory (for authentication). These are covered by Microsoft's privacy statement.

The app is hosted on Cloudflare Pages. Cloudflare may process standard web request metadata (IP address, user-agent) as part of its CDN and security services. See Cloudflare's privacy policy.

9. Your Rights (GDPR / CCPA)

Because we do not collect or store personal data on our servers, most data subject rights are exercised directly through your Microsoft account. You have the following rights:

10. Children's Privacy

This add-in is not directed at children under 13 (or under 16 in the EEA). We do not knowingly collect data from children.

11. Security

All communication between the add-in and Microsoft Graph is encrypted via HTTPS. The add-in is hosted on Cloudflare Pages with HTTPS enforced. Because we do not store email data on our servers, there is no server-side data breach risk for your email content.

12. Disclaimer and Limitation of Liability

This add-in is provided "as is" without warranty of any kind, express or implied. To the maximum extent permitted by applicable law, the developer shall not be liable for any indirect, incidental, or consequential damages arising from your use of the add-in.

13. Changes to This Policy

We may update this policy from time to time. The "last updated" date at the top of this page will be updated accordingly. Continued use of the add-in after a policy change constitutes acceptance of the updated policy.

14. Contact

For any questions about this privacy policy or your data, please contact us at [email protected]. We aim to respond within 2 business days.