Infrastructure Engineer · Tallinn, Estonia
I am an infrastructure engineer working on email platforms, deliverability and email security. I build and operate the systems that decide whether mail actually arrives: MTA clusters, SMTP transport, IP and domain reputation, and the authentication layer underneath them.
Day to day that means PowerMTA, KumoMTA, Postfix, Haraka, Momentum and GreenArrow in production; queueing, throttling and retry behaviour; DNS and the SPF, DKIM, DMARC, MTA-STS and TLS-RPT stack; IP pool design and warm-up; bounce, deferral and complaint classification; and blocklist remediation when reputation goes wrong. I have run outbound estates on bare metal and cloud across several hosting providers, and led the team that operated them.
I write here about the parts of this that are hard to find written down properly.
A reference for the responses that actually show up in mail logs, written from operating them rather than from the RFCs. What each one means, whether it is worth retrying, and what to change so it stops happening.
Original measurement of email authentication adoption across the public internet, with the methodology and the raw dataset published alongside the findings.
Open-source tooling for email operations: bounce and deferral classification, and authentication auditing.