Another utility to analyze state of deployment of security-related email protocols.
Needs Go toolchain.
go get github.com/foxcpp/mailsec-check
mailsec-check example.org
$ mailsec-check protonmail.com
-- Source forgery protection
[+] DKIM: _domainkey subdomain present; DNSSEC-signed; [+] SPF: present; strict; DNSSEC-signed; [+] DMARC: present; strict; DNSSEC-signed; -- TLS enforcement
[+] MTA-STS: enforced; all MXs match policy; [+] DANE: present for all MXs; DNSSEC-signed; no validity check done; -- DNS consistency
[+] FCrDNS: all MXs have forward-confirmed rDNS
[+] DNSSEC: A/AAAA and MX records are signed;
$ mailsec-check disroot.org
-- Source forgery protection
[+] DKIM: _domainkey subdomain present; DNSSEC-signed; [+] SPF: present; strict; DNSSEC-signed; [ ] DMARC: present; no-op; DNSSEC-signed; -- TLS enforcement
[ ] MTA-STS: not enforced; all MXs match policy; [+] DANE: present for all MXs; DNSSEC-signed; no validity check done; -- DNS consistency
[ ] FCrDNS: no MXs with forward-confirmed rDNS
[+] DNSSEC: A/AAAA and MX records are signed;