$ ls topics/shield/

Shield

3 articles.

Aug 4, 2026QA14 min read
You can't test email against a spec
Email is a federated protocol with decades of implementations behind it and an adversary working the gaps on purpose, so the set of things your product has to handle is discovered rather than designed. How we run QA at Mailprotector without a QA department.
Ben Hathaway·Chief Technology Officer
Jul 22, 2026Releases10 min read
Deployment Control: deploy today, roll out at your pace
The engineering story behind Shield's Deployment Control release: how deployment and rollout became separate steps, how health checks gate enablement, and the routing redesign that removed DNS from the process.
Ben Hathaway·Chief Technology Officer
Jul 21, 2026Shield11 min read
The evolution of Shield's mail flow architecture
Three versions of Shield's mail flow architecture, from a blunt MX record to a design that hands the last mile back to Microsoft, and what changed each time along the way.
Christian Maddox·Senior Software Engineer

You can't test email against a spec