Look up MX priorities and hostnames, identify null MX, and check for implicit A/AAAA mail routing.
Enter a domain to retrieve its MX records using DNS over HTTPS. Lower numerical priority means a more preferred mail exchanger.
An MX priority of 10 is preferred to 20. Equal priorities indicate equally preferred destinations; the number is not a quality or uptime rating.
A sole “0 .” MX record declares that a domain does not accept email. Missing MX is different: SMTP can fall back to the domain address records.
An MX answer identifies routing configuration. It does not confirm SMTP reachability, TLS support or the existence of any recipient.
No. MX applies to the whole domain, not to individual email accounts.
Check for null MX, NXDOMAIN and A/AAAA fallback separately. Those cases mean different things.