Privacy
Mister Plimsoll runs entirely on your Mac. It collects no analytics, no telemetry, and no usage statistics. Nothing is sent to any server I control.
Your configuration — the volumes you choose to monitor, your thresholds, your alert preferences — is stored in macOS user defaults on your Mac alone.
Credentials you give Mister Plimsoll for delivering alerts (the SMTP password for email and the user key for Pushover) are stored in your macOS Keychain, encrypted at the operating-system level. They never leave your Mac except to authenticate with the third-party service you’ve chosen.
What gets sent when an alert fires
When Mister Plimsoll sends an alert, the message contains your computer’s name (whatever you’ve named it in System Settings), the volume name, the percentage used, and the free-space figure. Depending on which channels you’ve enabled, that content travels through one or more third-party services:
- Email goes to your SMTP provider (Apple, Google, Fastmail, your employer, whoever you configure). Your provider can read the alert’s subject and body the same way they can read any other email you send.
- iMessage (direct-download edition only) alerts go through Messages.app on your Mac, which routes them through Apple’s iMessage service to whichever handle (Apple Account email or registered phone number) you configure. Apple’s privacy policy applies.
- Pushover alerts are POSTed to
api.pushover.netwith a Mister Plimsoll application token, your Pushover user key, the alert title, and the alert body. Pushover delivers the push to whichever devices you’ve registered with them. Pushover’s privacy policy covers how they handle the message en route. - Webhook alerts POST the same alert content to whichever URL you supply — a Slack incoming webhook, a Discord channel webhook, a Zapier or IFTTT or n8n endpoint, or your own backend. The destination handles the payload according to its own privacy policy. Mister Plimsoll itself does nothing more than send the single HTTP POST.
Mister Plimsoll never sends alert content (or anything else) to any server I control.
If you leave a tip, the path depends on the edition. In the direct-download edition, clicking Leave a tip redirects you to Stripe’s hosted checkout page; Stripe collects payment information per Stripe’s own privacy policy. In the Mac App Store edition, optional tips are StoreKit in-app purchases handled by Apple’s App Store. Either way, no payment information passes through anything I control.
The misterplimsoll.app website may keep standard server logs (IP address, timestamp, requested page, user agent) for operational and security purposes. These are not used for analytics, advertising, or any other purpose, and they aren’t shared with anyone. They are typically deleted within 60 days.
Reliability
Mister Plimsoll is stable software, but it is a single-person project and can still surprise you. Please don’t rely on it as your sole protection against running out of disk space, particularly on production machines, servers, or systems where running out of room would have serious consequences. Treat its alerts as one signal among several.
Liability
Mister Plimsoll is provided as-is, without warranty of any kind, express or implied. To the fullest extent permitted by law, Glenn Fleishman is not liable for any direct, indirect, incidental, consequential, or other damages arising from use or misuse of the software, including (but not limited to) data loss, missed alerts, hardware damage, downtime, or business interruption.
The software is free. By using it, you accept these terms. If you don’t agree, please don’t install or run it.