DNS Tools

MX Record Lookup

Look up a domain's MX records to see which mail servers handle its email.

Enter a domain below to instantly look up its MX (Mail Exchange) records - the DNS records that tell the internet which mail servers are responsible for receiving email for that domain, and in what priority order.

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Each MX record includes a priority number (also called "preference") and a mail server hostname. Lower priority numbers are tried first - a record with priority 10 is preferred over one with priority 20. If the lowest-priority server doesn't respond, mail servers automatically fall back to the next one, which is why many domains have 2 or more MX records for redundancy. A domain with no MX record at all cannot receive email - some services fall back to the A record in that case, but this isn't guaranteed and is considered misconfigured. JustChecker tracks your DNS records continuously and alerts you the moment something changes.

What Is an MX Record?

MX (Mail Exchanger) records tell other mail servers where to deliver email for a domain. Each record has a hostname and a priority number. This tool lists a domain's MX records in priority order.

When to Use It

After setting up Google Workspace, Microsoft 365 or another email provider.
When a domain stops receiving email.
To find out which email provider a domain uses.

How to Use It

Enter the domain (not the email address).
Check that the listed hosts match your email provider's instructions.

Understanding the Result

A lower priority number is tried first; higher numbers are backups. Hostnames such as aspmx.l.google.com indicate Google Workspace and *.mail.protection.outlook.com indicates Microsoft 365. No MX records means the domain cannot receive email in the normal way.

Limitations

MX records alone do not show whether mail is trusted - check authentication with the SPF Checker and DMARC Checker, or get the full picture with the Email Security Summary.

Frequently Asked Questions

It controls which mail server is tried first when someone sends you an email. Lower numbers have higher priority - a server at priority 10 receives mail before one at priority 20. If the top-priority server is unreachable, sending servers automatically retry the next one in order.

This is normal and often intentional - it provides redundancy (a backup mail server if the primary is down) or splits mail handling across providers, like a primary Google Workspace/Microsoft 365 server plus a secondary spam-filtering service.

That domain generally cannot receive email at all. A few mail systems will fall back to the domain's A record as a last resort, but this is non-standard behavior you shouldn't rely on - a working domain that sends or receives email needs at least one valid MX record.

DNS changes take time to propagate, and MX records in particular are often cached with their own TTL by mail servers around the world - it can take anywhere from a few minutes to 48 hours. Use our DNS Propagation Checker to see whether major resolvers have picked up your new records yet.