Free tool · DNS check

MX Lookup

Look up the mail servers a domain publishes, in priority order, with TTLs and common configuration problems.

How it works

What gets checked

We query the domain’s MX records, sort them by priority (lowest first), and flag invalid entries, IP addresses used as targets, duplicates, and Null MX (a record that says the domain accepts no mail).

Limits

What it cannot tell you

  • It reads public DNS through a DNS-over-HTTPS resolver. It does not send mail and cannot say whether a message will be delivered or pass authentication.
  • No MX records does not always mean no mail: senders may fall back to the domain’s A/AAAA record. This tool does not check that fallback.
  • It does not connect to the mail servers.
  • Anonymous use is limited to 30 checks per hour.
FAQ

Common questions