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
How to Check a DKIM Record
A practical guide to checking a DKIM record, finding the right selector, validating the TXT record, and spotting common DKIM setup problems.
How to Check a DMARC Record
A practical guide to checking a DMARC record, understanding the main tags, and spotting common DMARC issues before enforcement causes problems.
How to Check an SPF Record
A practical guide to checking an SPF record, including where to look, how to read includes and qualifiers, and how to spot common SPF problems.
Return-Path vs From Address: What's the Difference?
Learn the difference between the Return-Path and From address in email, why SPF checks one while DMARC protects the other, and how mismatches affect deliverability.
SPF vs DKIM vs DMARC: What Is the Difference?
Learn the difference between SPF, DKIM, and DMARC, how they work together, and why you usually need all three for a strong email authentication setup.
What Is a DMARC Record? Tags, Policy, and Examples
Learn what a DMARC record is, what the main DMARC tags mean, how policy works, and how to review a DMARC record correctly.
What Is an SPF Record? Syntax, Mechanisms, and Limits
Learn what an SPF record is, how SPF syntax and mechanisms work, what qualifiers mean, and what to check when reviewing an SPF policy.
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 what DKIM is, how DKIM works, what a selector does, 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.