How to Check an MX Record

To check an MX record properly, query MX for the exact domain that should receive mail. That gives you the published preference values and target hostnames that receiving systems are expected to use.

If there are no MX records where you expect them, inbound mail routing may be broken or at least unclear.

• MX Lookup

An MX record is not just a hostname. It is a priority plus a target. Lower numbers are preferred first, so a technically valid set of MX records can still be wrong if the priorities send mail to the wrong platform.

0 mail.protection.outlook.com

The next question is whether the MX target belongs to the provider you actually expect to be receiving mail. Migrations often leave old MX values in place or mix providers accidentally.

• Email Provider Setup Checker
• How to tell which email provider a domain uses

The MX value itself is a hostname, so you should also confirm that hostname resolves correctly. If the target hostname is broken, mail can fail even though the MX record exists.

• Query the domain's MX records
• Review the number of MX records and their priorities
• Check whether the targets look like the intended mail provider
• Resolve the MX target hostnames if needed
• If the setup looks mixed, compare it with provider-specific expectations

If you want to validate this topic in practice, these DNS Pro tools are the fastest next step.

• MX Lookup
• Email Provider Setup Checker
• Email Security Check