Cumps · Geek.

SPF, DKIM, DMARC: Getting Mail Delivered

Tue, 08 Sep 2026 10:00:00 +0200

Last week ended with Stalwart running on two nodes. At that point I had a mail server in the same sense that a teenager with a learner’s permit has a car: technically true, not yet trusted by anyone. The big providers treat unknown mail servers as guilty until proven innocent, and the proof is a stack of DNS records and protocols that grew up as patches on a protocol from 1982.

One Binary for All of Email

Tue, 01 Sep 2026 10:00:00 +0200

Email is the service this whole project exists for, and the one my family will not forgive me for breaking. It’s also the service with the scariest reputation in self-hosting. Part of that reputation comes from the traditional stack: Postfix for SMTP, Dovecot for IMAP, rspamd for spam, something else for CalDAV, each with its own config language, its own failure modes, and its own opinions about the others.

LUKS on Every Data Volume

Tue, 25 Aug 2026 10:00:00 +0200

The threat model for a rented server is simple to state: my data sits on disks I will never see, in a data center I will never visit, handled by people I will never meet. Disks get decommissioned, snapshots get copied, hardware gets recycled. I can’t control any of that. What I can control is whether the bytes on those disks mean anything without a passphrase. Last week covered the secrets that never leave the git repository; this week is about the disks those secrets unlock.

Secrets That Live in Git

Tue, 18 Aug 2026 10:00:00 +0200

This is the first of the foundation retrospectives I promised in the catch-up post. We’re going back to December, before a single server existed, when the first real decision of the project wasn’t about compute or DNS. It was: where do the secrets live?

Catching Up: Six Months of Building, Zero Posts

Tue, 11 Aug 2026 10:00:00 +0200

The last post on this blog is dated February 23rd. It ended with a to-do list: monitoring, backups, Git hosting, password management, migrating out of Google. Then nothing for almost six months.

Building a Self-Hosted Platform: Architecture Overview

Mon, 23 Feb 2026 11:00:00 +0100

In the previous post I explained why I’m moving my family off Google Workspace and onto self-hosted infrastructure. This post is about how it’s built.

Why I'm Self-Hosting Everything

Sun, 22 Feb 2026 10:00:00 +0100

A few months ago my nine-year-old asked me why YouTube always seems to know what she wants to watch. I gave her a half-answer about algorithms and changed the subject. That evening, after the kids were in bed, I sat staring at my Google Workspace admin console and felt uneasy for the first time in years. Not because Google had done something wrong exactly, but because I finally sat with the question: why is every email my family sends, every calendar invite, every contact stored on servers I have zero control over, in a jurisdiction that doesn’t answer to us?

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