Full check of the domain
One grade for how your security looks from the outside. Email, DNS and web are weighed together, and we explain in plain language what raises and lowers it.
About the grade
What it measures
The grade weighs together three areas that can all be read from the outside: email (SPF, DKIM, DMARC, MX and blacklist), DNS and domain (name servers, SOA, address, DNSSEC, CAA and domain age), and web (TLS certificate, security headers and subdomains). Each shortcoming lowers the grade by a different amount depending on how serious it is.
What it does not measure
This is an external view. It does not see your accounts, your sharing, your apps or your security settings inside Microsoft 365.