Privacy Policy

Last updated 11 October 2026. Applies to the Postfach apps for macOS and iOS and to this website, both from esense GmbH, Switzerland.

The short version: Postfach collects nothing. It has no server of its own, creates no account with us, and sends nothing anywhere except to the mail servers you configure, with your own credentials, over an encrypted connection. The rest of this page says the same thing in more detail.

What the app connects to

Postfach connects only to the IMAP and SMTP servers of the mail accounts you add, to read, send, and manage your mail there. Those servers belong to your mail provider, not to us; what they keep is governed by their privacy policy. Postfach also asks the Domain Name System for the address of a mail server when you add a Zimbra account, in the same way any mail app resolves a host name.

What stays on your device

Your messages, attachments, folders, a search index of the text, your contacts' names and addresses as seen in your mail (for address completion), your templates, and your settings are stored on your Mac, iPhone, or iPad in the app's own container. Your passwords are stored in the Keychain of your device. Nothing of this leaves the device except as mail you send to your mail server.

What we do not do

• No analytics, no usage statistics, no crash reporting of our own.
• No advertising, no tracking, no identifiers shared with anyone.
• No copy of your mail, your addresses, or your passwords on any server of ours. We have none.
• No AI reads your mail: no summaries, no smart replies, no model of ours or anyone's sees a word of it.
• No remote content loaded from messages until you ask for it, and no scripts run from messages, ever.

Purchases

Postfach Pro is bought through Apple's App Store. Apple processes the payment and tells the app whether the purchase exists; we receive no name, address, or payment detail from it. Apple's privacy policy applies to the purchase.

Notifications and background refresh

Notifications for new mail are created on your device from the mail the app fetched itself; no notification service of ours is involved. On iOS, Background App Refresh lets the app check your inboxes while it is not on screen, again by connecting to your mail servers and nowhere else.

Diagnostics you may send us

If you ask for help, you may choose to send us the app's log from Settings. It contains folder names, message counts, timings, and error texts, never the content of messages, addresses, or passwords. It is used to answer your request and then deleted.

This website

This site is static. It sets no cookies, stores nothing in your browser, loads nothing from anyone else, and has no analytics script and no forms; the only links to third parties go to Apple (the App Store and its licence agreement), to Microsoft's help and account pages, and to an open-source licence on GitHub, and they are followed only if you click them. Our hosting provider keeps ordinary server access logs, which record the address of each request, the page asked for, the browser, the page that led here, and the time. From these logs we count how many visitors the site had per day, which pages they opened, and where they came from. The count is made on the hosting; what we keep of it is totals, never addresses. Beyond that we use the logs only to run and protect the site. If you write to info@postfach-app.com, we keep your message and your address for as long as it takes to answer you and to keep a record of it.

Your rights

Under the Swiss Federal Act on Data Protection you may ask what data we hold about you, have it corrected, or have it deleted, and you may complain to the Federal Data Protection and Information Commissioner. Because the app collects nothing, this concerns only the server logs of this website, mail you send us, and a log you choose to attach to a support request.

Children

Postfach is a general mail client and collects no data from anyone, of any age.

Changes

If this policy changes, the new version appears here with a new date. Since the app collects nothing, changes will be rare and small.

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