What this check shows
MX records tell sending mail systems which servers accept email for a domain. Each record includes a hostname and a priority; lower numbers are normally attempted first.
A global comparison is useful after changing email providers, adding a backup mail exchanger or diagnosing why some senders still deliver to an old platform.
When to use it
- Email provider migrations
- Inbound mail delivery failures
- Incorrect MX priorities
- Removing obsolete mail servers
How to read the result
- The MX target should be a hostname, not an IP address, and that hostname must resolve independently.
- Different priority values are normal when a domain has primary and backup mail exchangers.
- No MX answer does not always prevent delivery because some senders may fall back to the domain A record, but publishing explicit MX records is safer.
Questions
Does a lower MX number mean higher priority?
Yes. A sender normally attempts the lowest preference value first.
Can MX propagation affect only some senders?
Yes. Sending systems use different recursive resolvers, so cached MX answers can expire at different times.
Related DNS tools
Compare DNS answers worldwide after a record, provider or nameserver change.
Check published IPv4 addresses for a domain across independent DNS resolvers.
Check IPv6 addresses and AAAA record propagation across public DNS resolvers.
Verify canonical name aliases and CNAME propagation across DNS resolvers.
Inspect SPF, DKIM, DMARC, ownership verification and other TXT records.
Compare authoritative nameserver records returned by public DNS resolvers.