Email Security Tools
Use these tools when you are diagnosing mail delivery, validating authentication records, or checking how a domain presents itself to receiving mail systems.
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Start With The Right Tool
Run A Full Mail Posture Check
Start here if you want one place to review SPF, DMARC, DKIM, MTA-STS, TLS-RPT, and BIMI together.
Troubleshoot SPF Or DMARC
Use focused record-specific checkers when one part of mail authentication is failing or looks suspicious.
Analyze A Received Message
When a real email is failing or being flagged, parse the headers to see authentication and routing results directly.
Featured Tools
Article Topic Hubs
Email Security Articles
Read practical guides on SPF, DMARC, DKIM, BIMI, MTA-STS, and related email authentication topics.
DNS Troubleshooting Articles
Read troubleshooting guides for propagation, mail issues, DNS misconfiguration, and common operational failures.
Setup And Migration Guides
Read setup and migration guides for common DNS and email configuration tasks.
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Email & Security
SPF Checker
Break down SPF mechanisms, redirects, includes, and lookup count.
SPF Flattener
Generate a flattened SPF-style output from the current effective SPF policy.
DMARC Checker
Inspect DMARC policy, reporting, and alignment tags.
DKIM Checker
Check DKIM records with a selector.
Email Security Check
Review SPF, DMARC, DKIM, MTA-STS, TLS-RPT, and BIMI together.
MTA-STS Check
Check the MTA-STS TXT record and HTTPS policy file.
TLS-RPT Check
Inspect TLS-RPT reporting records.
BIMI Check
Inspect BIMI TXT records and parsed BIMI tags.
Blacklist Checker
Check whether a domain or IP appears on common blocklists.
Email Header Analysis
Analyze email headers for SPF, DKIM, DMARC, and routing clues.
Email Provider Setup Checker
Compare Google Workspace or Microsoft 365 mail DNS patterns.
Featured Articles
How to Check DNS Delegation Correctly
Learn how to check DNS delegation by comparing parent and child NS records, SOA responses, and glue records to find broken or inconsistent delegation.
How to Check If an IP or Domain Is Blacklisted
Learn how to check whether an IP address or domain is blacklisted, what DNSBL results really mean, and how to interpret blocklist findings before escalating.
How to Identify a Hosted Service from DNS Clues
Learn how to identify a hosted service or platform from DNS clues such as CNAME targets, MX patterns, TXT records, and provider-specific hostname conventions.
How to Read CAA Records Correctly
Learn how to read CAA records, understand issue, issuewild, and iodef tags, and tell whether certificate issuance is properly restricted for a domain.
How to Read CNAME Chains Correctly
Learn how to read CNAME chains, understand alias targets step by step, and spot stale, looping, or takeover-prone CNAME configurations.
How to Read DKIM Records Correctly
Learn how to read DKIM records, understand selector hostnames and key tags, and spot the difference between valid publishing and weak configurations.