The cqwerty blog

Security, explained the way operators actually fix it.

Plain language field notes on domain posture, email authentication, and web hardening. Written for the operator who needs to ship the fix this afternoon, not next quarter.

FeaturedDMARCEmail

DMARC aggregate reports, reading them like an operator.

Aggregate reports show who sends mail as your domain. How to read them, route them, and act on them.

Read the storyApr 21, 20266 min read

What this covers

TLS, email auth, and HTTP headers, read the way an operator triages them.

Every check maps to a free tool you can run on your own domain.

Public surface only · no intrusive testing

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Every guide, by what you are fixing.

30 guides published

Apr 18, 20267 min

What public security signals tell you about a domain, and where most sites slip.

A walk through the public posture signals a scan reads, TLS, email auth, and HTTP headers, and the pattern of misses we see most often. Run the same checks on your own domain.

DataResearch

Apr 18, 20267 min

SPF flattening, fixing the 10 lookup limit.

Flattening resolves include mechanisms into IPs. When to use it, how to do it, what can go wrong.

SPFEmail

Apr 17, 20266 min

HSTS, forcing HTTPS without surprise outages.

How HSTS works, when to enable preloading, and the rollback plan if something breaks.

HSTSHTTPS

Apr 17, 20266 min

DNSSEC, end to end.

Cryptographic signatures on DNS records. What it blocks, how to enable it, and how to verify the chain.

DNSSECDNS

Apr 17, 20265 min

TLS certificate chains, when HTTPS quietly breaks.

Incomplete chains cause silent trust errors. How chains work, how to verify them, how to fix them.

SSLCertificates

Apr 17, 20266 min

Cookie security, the flags every dev should set.

Secure, HttpOnly, SameSite. The flags that block session hijacking and the defaults you can paste in.

CookiesWeb

Apr 17, 20267 min

DNS record types, A, AAAA, CNAME, MX, TXT, more.

The record types that actually matter, what they do, and how to configure them for security and reliability.

DNS

Apr 17, 20265 min

MX records, configuring email delivery without surprises.

How to set MX records, verify them, and avoid the common mistakes that break inbound mail.

MXEmail

Apr 17, 20265 min

Redirect chains and security, what can go wrong.

Open redirects, redirect loops, HTTP to HTTPS gaps. How to audit, how to fix, and what a scan flags.

RedirectsWeb

Showing 9 of 29 guides

Reading these is how operators get sharp.

Run a free scan and the graded report cites the same checks these guides unpack.

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