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.
Command examples
Use these dig commands when you need to compare DNSRadar with a terminal check or collect evidence for a DNS provider.
dig example.com MX +short
dig @1.1.1.1 example.com MX
dig mail.example.com A +shortTroubleshooting focus
Use this page when inbound email routing changes, messages still arrive at an old provider, or a mail platform asks you to verify MX propagation. MX results should be read together with target A or AAAA records and outbound authentication records.
Practical examples
- After moving to a new mail provider, compare MX priorities and hostnames globally.
- Before disabling the old provider, confirm that public resolvers no longer return the previous MX set.
- When delivery is inconsistent, check whether affected senders may still be using cached MX data.
- After MX changes, verify SPF, DKIM and DMARC TXT records separately.
Common mistakes
Pointing MX to an IP address
MX records should point to hostnames, and those hostnames should resolve separately.
Confusing MX with SPF
MX controls inbound delivery; SPF authorizes outbound senders.
Deleting backup MX without checking priority
Senders use preference values to decide which mail exchanger to try first.
Forgetting TXT records during DNS provider migration
Email authentication can break even when MX records look correct.
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.