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Tag: For IT Professionals

Technical guides, configuration, and diagnostics for email authentication aimed at IT administrators and developers.

How DNSSEC Protects SPF, DKIM, and MX Records

How DNSSEC Protects SPF, DKIM, and MX Records

DNSSEC protects email DNS records from forgery. We break down four concrete attacks on SPF, DKIM, DMARC, and MX — and how cryptographic signatures prevent them.

· 7 min read
What Is DANE and How It Secures Email Transport

What Is DANE and How It Secures Email Transport

DANE verifies mail server TLS certificates directly via DNS and DNSSEC. Learn how TLSA records work, how to deploy DANE, and how it compares to MTA…

· 8 min read
What Is a CAA Record and How to Restrict TLS Certificate Issuance

What Is a CAA Record and How to Restrict TLS Certificate Issuance

A CAA record specifies which certificate authorities may issue TLS certificates for your domain. Learn how to configure it with practical examples.

· 6 min read
How to verify if your domain has DNSSEC

How to verify if your domain has DNSSEC

How to verify DNSSEC for your domain using online tools and dig commands. Interpret results, fix common issues, and understand the impact of broken…

· 5 min read
DKIM Fail — Diagnosis and Solutions

DKIM Fail — Diagnosis and Solutions

DKIM fail means the recipient could not verify the email's digital signature. Learn the causes of failure and how to systematically fix them.

· 9 min read
ARC — Email Authentication Across Forwarding

ARC — Email Authentication Across Forwarding

ARC (Authenticated Received Chain) preserves email authentication results across forwarding hops. Learn how ARC works and when to deploy it.

· 7 min read
DKIM Selectors — What They Are and How to Use Them

DKIM Selectors — What They Are and How to Use Them

A DKIM selector links an email signature to its public key in DNS. Learn how selectors work, naming conventions, and how to rotate keys safely.

· 6 min read
MTA-STS and TLS-RPT — Securing Email Transport

MTA-STS and TLS-RPT — Securing Email Transport

MTA-STS enforces encrypted TLS connections for inbound emails and prevents downgrade attacks. Learn how to deploy MTA-STS and TLS-RPT step by step.

· 8 min read
SPF 10 DNS Lookup Limit — How to Count and Fix It
SPF

SPF 10 DNS Lookup Limit — How to Count and Fix It

SPF records are limited to 10 DNS lookups. Learn which mechanisms count, how to audit your record, and four strategies to stay within the limit.

· 5 min read
DMARC Fail — What It Means and How to Fix It

DMARC Fail — What It Means and How to Fix It

DMARC fail means your email failed authentication — usually due to missing SPF/DKIM or alignment issues. Learn how to diagnose the cause and fix it.

· 7 min read
DNS Records for Email — A Complete Guide

DNS Records for Email — A Complete Guide

MX, TXT, CNAME, PTR — every DNS record you need for email delivery and security in one place. Examples, rules, and a ready-to-use checklist.

· 8 min read
How to Set Up SPF, DKIM, and DMARC for Google Workspace

How to Set Up SPF, DKIM, and DMARC for Google Workspace

Step-by-step guide to setting up SPF, DKIM, and DMARC for Google Workspace. From DNS records to DKIM activation in Admin console and DMARC deployment.

· 8 min read