6 articles
Complete guide to email-related DNS records: MX, SPF, DKIM, DMARC, MTA-STS, TLS-RPT, BIMI, PTR. Each record explained with concrete examples.
How to read email headers: Received, Return-Path, Authentication-Results, ARC, DKIM-Signature. Complete guide to diagnosing deliverability issues.
Complete dissection of a DKIM-Signature header: algorithm, body hash, canonicalization, selector, timestamp. Understanding the verification process step by step.
Why your DKIM key size matters: history of RSA 512/768/1024-bit vulnerabilities, migration to 2048 bits, and Ed25519 as the future standard.
Technical explanation of dual DKIM signatures: why your ESP adds its own signature, the role of Gmail and Yahoo Feedback Loops, and the impact on DMARC alignment.
Complete guide to DKIM (DomainKeys Identified Mail): how cryptographic signatures work, DNS setup, key rotation and troubleshooting.