Email and domain security

The email header analyzer takes a raw message and lists the Received path. How to read email headers explains those fields. Email auth checks a domain MX, SPF, and DMARC records. SSL/TLS checks a certificate. Security headers grades the response headers on a site. The blacklist check looks up an address on DNS blocklists.

A Received header usually names a sending address. IP lookup shows that address's ASN, ISP, reverse DNS, and whether the IPv4 blacklist check listed it. The block around it is on the subnet calculator and the CIDR calculator.

The other groups are leak tests, IP lookup and geolocation, and network diagnostics.