checkdmarc

A Python module and command line utility for validating SPF and DMARC DNS records

Features

• API and CLI
• Can test multiple domains at once
• CLI output in JSON or CSV format
• Parsing and validation of many DNS records related to email
  • SOA
  • MX
    • Tests STARTTLS and TLS support on each mail server, including certificate validation
  • SPF
    • Counts the number of DNS lookups required in each part of the SPF record
  • DMARC
  • MTA-STS
    • Checks both the DNS record and the policy provided over HTTPS
  • SMTP TLS reporting
  • BIMI
    • Validates the SVG format and mark certificate
  • DNSSEC