Privacy Policy

Effective date: March 3, 2026

This Privacy Policy explains how Fastmail Checker (the "Extension", "we", "our", "us") handles data when you use the browser extension and related services.

Summary

Fastmail Checker is designed to process the minimum data needed to show unread Fastmail counts and optional notifications. Data is processed locally in your browser extension and in transit to Fastmail APIs. We do not store message content on our servers and the relay is intended to operate as a pass-through service.

Data We Process

Depending on features you use, we process the following categories of data:

Account and authentication data: Fastmail email address, account display name, Fastmail user/account identifiers, OAuth access token, OAuth refresh token, and token expiry metadata.
Mailbox metadata: unread counts and limited message metadata needed for the popup UI and notifications (for example: message id, sender name/email, subject, preview, receive time, and mailbox/keyword state for message actions).
Settings and operational data: polling interval, notification preferences, Do Not Disturb state, and timestamps used for polling/notification behavior.
License check data: primary email address may be sent to a subscription endpoint to determine paid/free status, if license checking is enabled.
Optional diagnostic logs: if developer mode is enabled, API request/response diagnostics may be stored locally in your browser for troubleshooting.

How Data Is Collected

You provide data when you connect a Fastmail account through OAuth.
The Extension retrieves mailbox data from Fastmail APIs to provide unread counts, previews, and message actions.
The Extension stores settings and state generated during normal operation.

How We Use Data

Authenticate you with Fastmail and maintain account connection.
Fetch and display unread counts and message previews.
Power extension features (badge updates, notifications, Do Not Disturb, quick actions).
Enforce account-tier limits and license status (where applicable).
Troubleshoot technical issues when optional diagnostics are enabled.

Storage and Retention

Extension state is primarily stored locally using browser extension storage on your device.
OAuth relay traffic is processed in transit to Fastmail APIs. The relay is intended as a pass-through service, and not a user-content archive.
We do not intentionally retain server-side logs containing message content from relayed Fastmail API traffic.
Data remains stored until you remove the account, clear extension/browser storage, or uninstall the extension.
Optional developer logs are stored locally and can be cleared from the extension UI.

Data Sharing and Disclosure

We do not sell personal data.

Data may be shared only as needed with:

Fastmail: to authenticate and access mailbox data you request.
Infrastructure providers: hosting/network providers that process requests to operate the service.
Legal/compliance recipients: if required by law, regulation, legal process, or to protect rights and security.

Security

We use reasonable administrative and technical safeguards designed to protect data in transit and reduce unauthorized access. No method of transmission or storage is 100% secure.

Your Choices and Controls

Disconnect accounts in the Extension options page.
Clear optional diagnostic logs in the Extension options page.
Uninstall the Extension to stop all processing by the Extension.
Clear extension/browser local storage to remove locally stored account/settings/message metadata.

Children's Privacy

Fastmail Checker is not directed to children under 13, and we do not knowingly collect personal data from children.

International Data Transfers

Depending on your location and service infrastructure, data may be processed in countries other than your own.

Changes to This Policy

We may update this Privacy Policy from time to time. We will post updates on this page and revise the effective date.

Contact

For privacy questions or requests, or show what code the proxy runs, contact [email protected].