Email Security Articles
Use these guides when you need to understand mail authentication policy, reporting, alignment, and the records that affect inbox trust and spoofing protection.
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Email Security Check
Review SPF, DMARC, DKIM, MTA-STS, TLS-RPT, and BIMI together.
SPF Checker
Break down SPF mechanisms, redirects, includes, and lookup count.
DMARC Checker
Inspect DMARC policy, reporting, and alignment tags.
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Email Security
DMARC Record Explained: Tags, Policy, and Examples
Understand what a DMARC record does, what each DMARC tag means, how policies work, and how to review a DMARC record correctly.
SPF Record Explained: Syntax, Mechanisms, and Limits
Learn how an SPF record works, what common SPF mechanisms mean, how qualifiers affect policy, and how to avoid typical SPF mistakes.
What Is BIMI? Email Brand Indicators Explained
A practical guide to BIMI, including what the BIMI record contains, how selector-based publishing works, and how BIMI fits into email trust.
What is DKIM and how does it work?
Learn how DKIM works, what a selector is, what the public key record contains, and why DKIM matters for email authentication.
What Is DMARC and How Does It Work?
Learn what DMARC is, how DMARC uses SPF and DKIM alignment, what policy modes mean, and how DMARC helps prevent domain spoofing.
What Is MTA-STS? SMTP TLS Policy Explained
Learn what MTA-STS is, how it enforces TLS for email delivery, what the policy looks like, and how it works with DNS and HTTPS.
What is SPF and how does it work?
Learn what SPF is, how SPF records are evaluated, what include and all mechanisms mean, and how to troubleshoot common SPF problems.
What is SPF flattening?
A practical guide to SPF flattening, including what a flattened record looks like, why teams consider it, and what risks it introduces.
What Is TLS-RPT? SMTP TLS Reporting Explained
A practical reference guide to TLS-RPT, including what the record looks like, what the tags mean, and how it fits alongside MTA-STS.