https://ownchain.systems/tags/email-security/ Recent content in Email-Security on Ownchain Systems Hugo en-us Sun, 30 Aug 2026 00:00:00 +0000 https://ownchain.systems/codex/002-mail-auth/ Sun, 30 Aug 2026 00:00:00 +0000 https://ownchain.systems/codex/002-mail-auth/ <p><strong>Classification:</strong> Perimeter Defense &amp; Mail Authentication<br> <strong>Status:</strong> Implemented &amp; Verified</p> <hr> <h2 id="executive-summary">Executive Summary</h2> <p>This report covers auditing, remediating, and enforcing cryptographic and domain-level email authentication records (SPF, DKIM, and DMARC) across a multi-service custom domain. The objective was resolving silent delivery failures for automated application notifications, aligning third-party transactional mail providers, and enforcing a strict quarantine policy to protect domain reputation against spoofing and phishing attempts.</p> <hr> <h2 id="threat-model--problem-statement">Threat Model &amp; Problem Statement</h2> <p>When operating self-hosted services alongside third-party transactional email relays and professional mail routing, misaligned authentication headers lead to two major failure modes:</p>