What is an MX record?
An MX (Mail Exchange) record is a DNS entry that tells the internet which mail server is responsible for receiving email on behalf of a domain. Without at least one valid, correctly prioritized MX record, a domain cannot receive mail at all – so checking it is usually the first step in diagnosing a delivery problem.
What this lookup shows
Enter any domain to see every MX record it publishes, along with each record's priority number. Lower priority numbers are tried first; a domain with several records is simply listing backup mail servers in case the primary one is unreachable.
Common reasons to run this check
- Confirming a new domain is ready to receive mail after DNS changes.
- Diagnosing bounced messages – a missing MX record is one of the most common causes.
- Verifying that a migration to a new email provider (e.g. moving to Google Workspace or Microsoft 365) has fully propagated.
- Spotting typos in an email address before adding it to a mailing list – a domain with no MX record at all is a strong red flag.
DNS changes can take anywhere from a few minutes to 48 hours to fully propagate, so a fresh check after any DNS edit is the fastest way to confirm the change actually took effect.