check_mx_all_flavours <domain>
It may be helpful to pipe the output though column -t
check all mx hosts of the given domain for
- reachability over ipv4 and ip6
- support for starttls
- support for TLS 1.2 and TLS 1.3
- support for RSA and ECDSA certificates
- whether the certificates are trusted
- whether DANE data are available and valid
The program is expected to be run on a system capable to establish outbound connection to port 25 over IPv4 and IPv4 and uses a validating DNS resolver.
The following tools must be available in $PATH:
- awk
- dig or kdig
- ldns-dane
- openssl
- sed
- sleep
Andreas Schulze