MX Record Lookup — Find a Domain’s Mail Servers

What is an MX record?

An MX record names a mail server that accepts email for a domain, and gives it a preference number. A sending server looks up the MX records for the part after the @, sorts them by preference, and tries them in order. If a domain has no MX record, mail delivery falls back to its A/AAAA record — or fails outright.

Fields in an MX record

Field	Meaning
Preference	A number from 0–65535. Lower is tried first. Equal values are load-balanced.
Exchange	The hostname of the mail server. It must resolve to an address of its own.
TTL	Seconds a resolver may cache the record set.

How to read the results

Rows are sorted by preference, so the first row is the server that receives your mail under normal conditions. Servers sharing a preference number split traffic between them; higher numbers are backups tried only when the lower ones do not answer. The preference number is a ranking, not a quality score — 10 is not "better" than 20 in any absolute sense.

Rules worth knowing

Lower preference wins. A record with preference 10 is tried before one with 20.
The exchange must be a hostname with A or AAAA records. Pointing an MX record at an IP address is invalid, and so is pointing it at a CNAME.
A single MX record with an empty target (.) is a "null MX" and explicitly declares that the domain accepts no mail at all (RFC 7505).
No MX record does not mean no mail: senders fall back to the domain’s A/AAAA record, which is rarely what you want.

Common problems

What you see	Usual cause
No records	The domain publishes no MX record. Inbound mail will fall back to the A record or bounce.
Mail goes to the wrong provider	Records from an old provider are still present. Every MX record for the domain should point at the current provider.
Changes have not taken effect	The old record set is still cached. Check the TTL and compare resolvers with the DNS Propagation Checker.
Mail is rejected as spam	MX is only the delivery path. Sender authentication is separate — check SPF, DKIM and DMARC with the Email DNS Checker.

Look up another record type

Each record type has its own page with the same explanation of its fields, or use the full DNS Lookup to query every common type at once.

A record AAAA record TXT record NS record CNAME record SOA record CAA record SRV record

Most often looked up alongside MX: TXT Record Lookup , A Record Lookup , SOA Record Lookup .

Data source: Public DNS-over-HTTPS resolvers. Queries go to the selected public resolver; results reflect that resolver’s cache. Learn about our data sources →

Frequently asked questions

What does the MX preference number mean?

It is the order in which sending servers try each host. Lower numbers are tried first; equal numbers share the load. The actual values do not matter, only their relative order.

How many MX records should a domain have?

At least two, pointing at different hosts, so mail still arrives if one is unreachable. Most hosted providers give you a set to copy verbatim.

Can an MX record point to an IP address?

No. The exchange field must be a hostname that has its own A or AAAA record. It must also not be a CNAME.

What is a null MX record?

A single MX record with preference 0 and a target of "." It tells senders the domain accepts no email, so they can reject immediately instead of retrying for days. It is defined in RFC 7505.

Does having MX records mean my email will be delivered?

No. MX controls where inbound mail goes. Whether your outbound mail is accepted depends on SPF, DKIM and DMARC alignment, which the Email DNS Checker reviews together.