Ghostmail Privacy Policy
Effective 17 June 2026 · Last updated 17 June 2026
Ghostmail (“the app”) is a macOS email client published by Matter ApS (“we”, “us”, “our”), a company registered in Denmark.
The short version: Ghostmail runs on your Mac, talks directly to your email providers, and Matter ApS operates no servers that receive your data.
1. We operate no servers and collect no data
Matter ApS does not run any backend service for Ghostmail. We do not receive, store, or have access to your email, your credentials, or any usage data. There is no analytics, no telemetry, no advertising, and no tracking of any kind. We do not sell or share data, because we never receive it.
2. Email account credentials
When you add an email account, your credentials are stored only on your Mac:
- Passwords and OAuth tokens are encrypted at rest using AES‑256‑GCM and kept inside the app’s sandboxed container.
- This data is never transmitted to Matter ApS.
- For Gmail and Outlook accounts, sign‑in uses the provider’s standard OAuth 2.0 flow. The resulting access and refresh tokens are stored locally and used solely to connect to your mailbox.
Removing an account from the app, or deleting the app, deletes this data from your Mac.
3. Email content
Ghostmail connects directly from your Mac to your email provider using standard protocols — IMAP and SMTP, or the Microsoft Graph API for some Microsoft accounts. Your messages are fetched, displayed, sent, and cached on your device. This content does not pass through Matter ApS at any point.
4. Optional AI email classification
Ghostmail includes an optional feature that uses an AI model to classify incoming emails as important or not. This feature is off by default and only operates if you turn it on and supply your own API key for a third‑party AI provider.
When enabled, for each classified email the app sends the following to the AI provider you selected:
- the sender’s name/address,
- the subject line, and
- up to the first 500 characters of the message body.
The provider is one you choose:
- Anthropic — sent to
https://api.anthropic.com, governed by Anthropic’s privacy policy. - OpenRouter — sent to
https://openrouter.ai, governed by OpenRouter’s privacy policy.
Your API key is stored locally on your Mac and used only to authenticate these requests. Matter ApS does not receive this data or your key. If you do not enable this feature, no email content is ever sent to any AI provider. You can disable it at any time in the app’s settings.
5. Local diagnostic logs
For troubleshooting, the app writes connection logs (IMAP/SMTP/Graph) to its local sandbox container on your Mac. These logs do not contain passwords or access tokens, are rotated/size‑limited, and never leave your device.
6. Third parties
The only third parties involved are services you connect the app to:
- Your email provider (e.g. Google, Microsoft, or any IMAP/SMTP host you configure).
- An AI provider (Anthropic or OpenRouter), only if you enable AI classification.
Each is governed by its own privacy policy. Matter ApS has no access to these accounts.
7. Data retention and deletion
All Ghostmail data lives on your Mac. We retain nothing because we receive nothing. To delete all app data, remove your accounts within the app or delete the app and its sandbox container.
8. Children
Ghostmail is not directed at children under 13 and we do not knowingly handle data from them.
9. Changes to this policy
We may update this policy. Material changes will be reflected by updating the “Last updated” date above and posting the revised policy at https://matteraps.com/ghostmail/privacy.
10. Contact
Questions about this policy or your data:
Matter ApS
Email: support.ghostmail@matteraps.com
Governing law: Denmark.