Articles about Security

9 articles

DMARC Email Security

Shadow IT and Email: The Tools Sending on Your Behalf Without You Knowing

How to detect SaaS tools sending emails from your domain without authorization: DMARC reports, unknown source identification, resolution workflow, and continuous monitoring.

Simon Bressier · · 7 min
DMARC Email Security

DMARC: Safely Migrating from p=none to p=reject

Step-by-step guide to moving your DMARC policy from none to reject: recommended timeline, shadow IT pitfalls, the role of RUA reports, and a migration checklist.

Simon Bressier · · 4 min
DMARC Email Security

Reading and Understanding DMARC Reports (RUA)

Practical guide to interpreting DMARC aggregate reports: XML format, legitimate vs suspicious sources, shadow IT, and how to use the data to strengthen your policy.

Simon Bressier · · 3 min
TLS Email Security

TLS and Email: Why SMTP Encryption Is Non-Negotiable

Everything about email encryption: STARTTLS, opportunistic vs enforced TLS, MTA-STS, DANE, TLS-RPT. Why Gmail shows a red padlock and how to avoid it.

Simon Bressier · · 3 min
DKIM Email Cryptography

Anatomy of a DKIM Signature: Every Field Explained

Complete dissection of a DKIM-Signature header: algorithm, body hash, canonicalization, selector, timestamp. Understanding the verification process step by step.

Simon Bressier · · 4 min
DKIM Security Cryptography

DKIM RSA Key Size: 1024 vs 2048 Bits and the Future with Ed25519

Why your DKIM key size matters: history of RSA 512/768/1024-bit vulnerabilities, migration to 2048 bits, and Ed25519 as the future standard.

Simon Bressier · · 3 min
BIMI Email Security

BIMI: Display Your Logo in Email Inboxes

Complete guide to BIMI (Brand Indicators for Message Identification): prerequisites, VMC certificate, DNS setup and impact on trust.

Simon Bressier · · 3 min
DMARC Email Security

How to Configure DMARC to Protect Your Domain

Complete guide to setting up a DMARC record on your domain: syntax, policies, RUA reports and best practices.

Simon Bressier · · 3 min
DKIM Email Security

DKIM: Sign Your Emails to Prove Their Authenticity

Complete guide to DKIM (DomainKeys Identified Mail): how cryptographic signatures work, DNS setup, key rotation and troubleshooting.

Simon Bressier · · 4 min
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