MX records control where inbound email is delivered. Each MX entry includes a hostname and a priority value; lower numbers are preferred. A correct MX setup ensures that mail servers can accept messages for your domain and provides failover if a primary server is down. This lookup shows the full MX set across resolvers so you can verify order and ensure all hosts are reachable.
Common mail issues are caused by missing MX records, using an incorrect hostname, or pointing to a host that does not accept mail. Also check that the target hostnames have valid A or AAAA records. If you use a hosted email provider, the MX records are usually documented and must match exactly. Even a small typo can cause mail delivery to fail.
If you need related checks, try Check Email DNS check online and Check TXT record online.
Priority determines which server should be tried first. Lower values are preferred. If the lowest priority host is unreachable, the sender will attempt higher priority hosts.
No. MX records must point to hostnames. Those hostnames must then resolve to A or AAAA records.
Multiple MX records provide redundancy and sometimes load distribution. If you see multiple values with the same priority, senders may choose any of them.
Some mail servers will fall back to the A record for delivery, but this is not reliable and not recommended. Explicit MX records are best practice.
You can connect to the mail server on port 25 to confirm it responds, and verify correct SMTP banners. Also check SPF and DMARC to improve deliverability.
It usually means propagation is incomplete or TTL caches differ. Check the authoritative name servers and wait for caches to expire.