MX Lookup
Look up a domain's MX records - the mail servers that receive its email - with priorities, and check that each one resolves to a real server.
Want the full picture - MX, SPF, DKIM, DMARC and more?
Run a full Domain CheckAbout these results
This tool reads a domain's public MX records at the moment of the lookup and checks that each mail server hostname resolves. Results reflect current public DNS and can be affected by caching and propagation (up to 24-48 hours). Guidance is general and not a substitute for your provider's official instructions. We don't store the domains you check.What is an MX record?
MX records tell other mail servers where to deliver email for your domain. Each has a priority - senders try the lowest number first, then fall back to higher numbers.
Implicit MX and null MX
- Implicit MX: no MX but an A/AAAA record - senders fall back to that address (RFC 5321). Explicit MX is more predictable.
- Null MX: a single
0 .record (RFC 7505) - the domain sends/receives no mail.
Common problems and fixes
- No MX records: add your provider's MX records, or publish a null MX if the domain shouldn't handle mail.
- MX host doesn't resolve: point each hostname at a valid server or remove stale entries.