DNSX
DNS records, SSL certificate, HTTPS redirect and mail servers, with a plain-language fix for anything wrong.
What DNSX checks
A / AAAA
The server address your website points to.
SSL certificate
Whether HTTPS works, who issued the certificate and when it expires.
HTTP to HTTPS
Whether visitors typing http:// are sent to the secure version.
MX, NS, TXT, CAA
Mail servers, nameservers, verification and certificate-authority records.