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MX Record Lookup

Enter a domain to find its MX records and mail server priorities.

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Enter a domain name and run a lookup to see its MX records.

How to use MX Record Lookup

The MX Lookup tool retrieves the mail exchange (MX) records for a domain, revealing which servers are responsible for receiving its email and in what priority order. MX records are the backbone of email delivery: when someone sends a message to you@example.com, their server looks up example.com’s MX records to decide where to deliver it. Use this tool to confirm a newly configured mail provider is correctly published, to diagnose why mail is bouncing, or to see which email service a domain uses before sending to it.

  1. Enter the domain whose mail configuration you want to inspect.
  2. Click Lookup to fetch the live MX records from DNS.
  3. Review each mail server and its priority value.
  4. Note the lowest-priority host — that is the preferred receiver.
  5. Cross-check against your mail provider’s recommended records.

How MX priority works

Each MX record has a priority number, and lower numbers are preferred. A sending server tries the lowest-priority host first and falls back to higher numbers only if that host is unreachable, which is how providers build in redundancy. A common configuration lists a primary at priority 10 and a backup at 20. If two records share the same priority, sending servers choose between them at random to spread load. Getting these numbers wrong can route mail to a backup server that is not fully configured, causing delays or bounces.

Example MX configuration
PriorityMail serverRole
10mail1.example.comPrimary receiver
20mail2.example.comBackup receiver

MX records and email deliverability

Valid MX records are necessary but not sufficient for reliable email. Receiving servers increasingly check that the domain also publishes SPF, DKIM and DMARC records to prove that mail claiming to be from it is legitimate. If your MX is correct but mail still lands in spam, the next step is to verify those authentication records. Conversely, if mail bounces immediately with a "no route to host" style error, the MX records themselves are usually missing or pointing at a server that no longer accepts mail.

Glossary

MX record
A DNS record naming a mail server responsible for receiving a domain’s email.
Priority
A number on each MX record; lower values are preferred by sending servers.
SMTP
Simple Mail Transfer Protocol — the standard for transferring email between servers.
Bounce
A delivery failure notice returned when mail cannot be delivered.
Fallback
Using a higher-priority-number backup server when the preferred one is unreachable.

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