Guides
Chaptered guides rather than blog posts: the whole subject in one place, updated rather than replaced, free to read without an account. Each one sits above the reference pages, so the exact steps for your registrar or mail provider are one click away.
Definitive guides · eight chapters each
A domain does not warn you. It works for years, and then on one specific morning the registry stops publishing its records and your website …
Read the guideEmail authentication is three separate mechanisms that people treat as one setting, deployed in an order that matters enormously and is almo…
Read the guideA subdomain pointing at a service you cancelled is not untidy. With several providers it is claimable, and whoever claims it controls what i…
Read the guideCertificates used to expire because somebody forgot. Now they expire because a job stopped running, and the job is on a server nobody curren…
Read the guideDNS is the piece of infrastructure every business depends on and nobody owns. It was configured once during a website project and has worked…
Read the guideA great many businesses do not control their own domain. It is on a former designer's account, registered to someone who left, or held by an…
Read the guideEvery business eventually runs on infrastructure configured by somebody who has left. The website was built by an agency three agencies ago,…
Read the guideAt some point a larger customer, an insurer or a buyer asks you to demonstrate that your infrastructure is looked after. The questions are m…
Read the guideAuthentication decides whether your mail is allowed to claim it is from you. Deliverability decides whether anyone actually receives it, and…
Read the guideMoving DNS is the change people avoid longest, because the failure mode is the whole business being unreachable and the process is described…
Read the guideAlmost everything written about choosing a domain extension is written by somebody who sells domain extensions, which is why it reads as a l…
Read the guideIf you look after websites for other people, their domains become your problem regardless of whose account they sit on. When one lapses, the…
Read the guideDomain security is discussed almost entirely as a technical subject, which is odd, because the overwhelming majority of domain losses are ad…
Read the guideAutomated certificate renewal works so well that it created a new problem: a process running somewhere, configured by somebody who has left,…
Read the guideField guides · five chapters each
Padding a five-chapter subject out to eight is exactly how this format stops feeling like a different class of page. These are deliberately shorter.
SPF is one DNS record with one job and a surprising number of ways to fail while looking correct.…
Read the guideDMARC is the instruction that makes SPF and DKIM mean something, and the one most likely to block your own mail if deployed in the wrong ord…
Read the guideAn incomplete certificate chain works perfectly in your browser and fails for other people, which makes it the hardest certificate problem t…
Read the guideNothing propagates. Caches expire, at different times, on different resolvers, and the difference between those two descriptions explains al…
Read the guideEvery domain carries status codes that describe what can and cannot be done to it, and most people first encounter them while trying to work…
Read the guideAlmost every question about why an email did or did not arrive is answered in its headers, and almost nobody knows how to read them.…
Read the guideWhy these exist
Search any of these subjects and you get one of three things: a registrar telling you to renew, a vendor explaining why their product is the answer, or a page that stops at the definition.
What is missing is the sequence — what actually happens, in what order, with what consequences, and what differs between providers. That takes chapters rather than paragraphs, which is why almost nobody writes it.
Each guide links down to the reference pages beneath it, so when you need the exact steps at your registrar or the exact records for your mail provider, they are one click away rather than crammed into an already long page.
Check yours
Everything these guides cover, checked on your own domain in about ten seconds.