Infrastructure that actually works.
Practical guides on email deliverability, SPF, DKIM, DMARC, server security and managed infrastructure — written by engineers who run it in production.
- security 21 July 2026 9 min read
HTTP security headers: what to set, what breaks, and what silently voids them
Seven HTTP security headers, the two that actually matter, what breaks when you enable them, and the nginx inheritance trap that silently voids the whole set.
Read article - security 22 June 2026 8 min read
The Essential Eight in plain English: a readiness checklist for Australian SMBs
The ASD's Essential Eight explained without jargon — what each control means, where small businesses fall short, and a self-check you can run today.
Read article - ai 22 June 2026 6 min read
Practical AI for Australian businesses: four automations that pay for themselves
Four AI automations that pay for themselves: document extraction, inbox triage, copilots over your own data, and quoting that replaces spreadsheets.
Read article - email 18 June 2026 6 min read
How to set up MTA-STS and TLS-RPT for your domain
MTA-STS forces sending servers to use TLS when delivering to your domain, blocking downgrade attacks. How to configure the policy file, DNS records and TLS-RPT.
Read article - email 11 June 2026 7 min read
Why Microsoft 365 DMARC failures happen and how to fix them
DMARC failures in Microsoft 365 environments usually trace back to one of four causes. Here's how to identify which one is happening on your domain and fix it.
Read article - security 4 June 2026 8 min read
Linux server hardening: a practical checklist for production
A working checklist for hardening a production Linux server: SSH, firewall, fail2ban, automatic updates, audit logging and more. Built from real environments.
Read article - email 28 May 2026 7 min read
How to check if your mail server is blacklisted and get it delisted
A blacklisted sending IP is rejected at the SMTP level before your message is read. How to check the major blacklists, read results and get listings removed.
Read article - email 28 May 2026 7 min read
MTA-STS: stop attackers from reading your inbound email in transit
Without MTA-STS, an attacker on the path to your mail server can strip TLS and read inbound email in plaintext. What it does, how to deploy it and verify it.
Read article - email 21 May 2026 8 min read
Migrating Exchange to Microsoft 365: four email delivery problems nobody warns you about
Most Exchange to M365 migration guides cover mailbox data, not delivery. Fix broken DKIM, orphaned SPF includes and hybrid flow issues before MX cutover.
Read article - email 14 May 2026 9 min read
Setting up DKIM in Microsoft 365: what the documentation misses
Set up DKIM in Microsoft 365 / Office 365: publish the two CNAME records and enable signing. DKIM is off by default and fails silently — here's the fix.
Read article - email 7 May 2026 10 min read
Reading DMARC aggregate reports: what the XML actually tells you
DMARC aggregate reports arrive as compressed XML almost nobody reads. Here's what each field means, the failure patterns to watch for, and how to act on them.
Read article - email 7 May 2026 5 min read
DMARC's p=none policy does nothing useful — here's what to do instead
A DMARC record with p=none doesn't protect your domain or affect delivery. It just collects reports. Here's how to read those reports and move to enforcement.
Read article - email 7 May 2026 5 min read
Why your email is going to spam — and how to fix it
SPF, DKIM and DMARC failures account for most email deliverability problems. Here's how to diagnose and fix each one.
Read article - email 7 May 2026 4 min read
Why Microsoft 365 DKIM stops signing your email — and how to fix it
Exchange Online DKIM can silently stop signing after licence changes, domain edits or tenant reconfigurations. How to detect the failure and re-enable signing.
Read article - email 7 May 2026 4 min read
The SPF 10-lookup limit: why it breaks email delivery
RFC 7208 caps SPF evaluation at 10 DNS lookups. Exceeding it invalidates your record and causes intermittent delivery failures. How to count lookups and fix it.
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Looking for step-by-step guides?
The resources section has practical checklists for email authentication setup, M365 migrations and more.