Email Security Checker
Analyse your domain's email authentication posture. Check SPF, DMARC, DKIM, MTA-STS and TLS-RPT - graded and explained in plain English.
SPF
SPF · Sender Policy Framework
Verifies which mail servers are authorised to send email for your domain.
DMARC
DMARC · Message Authentication
Defines how receivers should handle emails that fail SPF or DKIM checks.
DKIM
DKIM · DomainKeys Identified Mail
Cryptographic signatures that prove emails haven't been tampered with.
MTA-STS
MTA-STS · Strict Transport Security
Enforces TLS encryption for inbound email, preventing downgrade attacks.
TLS-RPT
TLS-RPT · TLS Reporting
Collects reports about TLS failures from sending mail servers.
Score
Score · Overall Grade
An A–F grade summarising your domain's email security posture at a glance.