MX-NXDOMAIN
An MX host does not exist
What it means
MX records point at a host name that has no address, so senders cannot deliver (or fall through to the next MX).
How to fix it
- 1Fix the MX host name or add the missing A/AAAA records for it.
Re-check after the change
DNS changes can take up to the record's TTL to be seen; use Re-run on the result page to bypass our 10-minute cache.